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 GB/T 1220—2007 1 ICS 77. 140. 20 H 40 GB National Standard of the People’s Republic of China GB/T 1220—2007 In place of GB/T 1220—1992  ________________________ Stainless Steel Bars 不锈钢棒 Issued on 14-05-2007 implemented on 01-12-2007 By General Administration of Quality Supervision, Inspection and Quarantine of  the People’s Republic of China and Standardization Administration Committee of the People's Republic of China

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  • GB/T 12202007

    1

    ICS 77. 140. 20 H 40

    GB National Standard of the Peoples Republic of China

    GB/T 12202007

    In place of GB/T 12201992 _______________________________________________________________________________

    Stainless Steel Bars

    Issued on 14-05-2007 implemented on 01-12-2007 By General Administration of Quality Supervision, Inspection and Quarantine of the Peoples Republic of China and Standardization Administration Committee of the People's Republic of

    China

  • GB/T 12202007

    1

    Forward This Standard is to be implemented in place of GB/T 12201992: Stainless steel bars. In comparison with Standard GB/T 12201992, the alterations of this Standard include the

    following points: It has added Technical terms and definitions and Contents in order sheet (See

    Chapter 3 and Chapter 4 hereof); Dimensions, contour, weight and permissible deviation is changed to direct quotation

    of stipulations specified in universal basic standard (Chapter 4 of 1992 edition; Chapter 6 of this edition);

    It has cancelled 6 grades, including 1Cr18Mn10Ni5Mo3N, 1Cr18Mn12Mo2Ti, 0Cr18Ni12Mo2Ti, 1Cr18Ni5Mo12Mo3Ti, 1Cr18Ni9Ti and 0Cr26Ni5Mo2, etc (Table 2 and Table 3 of 1992 Edition);

    It has added 6 grades and their properties, in including 022Cr18Mn22Ni5Mo3N, 022Cr23Ni5Mo3N, 022Cr25Ni6Mo2N, 03Cr25Ni6Mo3Cu2N, 17Cr16Ni2 and 05Cr15Ni5Cu4Nb, etc (See Table 2 and Table 7, Table 4 and Table 9, Table 5 and Table 10 hereof);

    It has adjusted the chemical compositions and phosphonium content of 21 steel grades (serial numbers: 1, 3, 13, 17, 23, 25, 35, 38, 39, 41, 43, 44, 52, 55, 62, 68, 93, 85, 98, 137 and 139) based on universal international steel grade (Table 2 in 1992 Edition and Tables 1 ~ 5 in this Edition);

    It has modified Smelting method that it shall apply initial molten steel plus out-of-furnace refining process in priority (Article 5.2 of 1992 edition and Article 7.2 of this edition);

    Delivery state is changed from It may not be treated if it is required by the Buyer into It may not be treated through negotiations between the Supplier and the Buyer, while for precipitation-hardening stainless steel bars it has added that annealing treatment to the delivery can be chosen by steel texture (Article 5.3 of 1992 edition and Article 7.3 of this edition);

    For Surface quality it has added that It may specify to remove scales formed from heat treatment by way of pickling, turning or other methods through negotiations between the Supplier and the Buyer, which should be indicated in contract (Article 7.8.3 of this edition);

    The heat treatment system for all kinds of stainless steel bars or test pieces is separated from mechanical property table and listed into Appendix A (Informative appendix) (Table 3 ~ Table 5 of 1992 edition; Table A.1 ~ Table A.5 of this edition);

    The yield strength for martensite and precipitation-hardening stainless steel is changed to necessary inspection indicator (Article 5.4.1.1 of 1992 edition; Table 9 and Table 10 of this edition);

    For 022Cr19Ni5Mo3Si2N(00Cr18Ni5Mo3Si2) steel, it has added that Brinell hardness value HBW shall be no more than 290 (Table 3 of 1992 edition; Table 7 of this edition);

    For 12Cr13(1Cr13) steel it has added that the lower limit of carbon content shall be 0.08%, while its percentage elongation after fracture is adjusted from 25% to 22% (Table 2 and Table 4 of 1992 edition; Table 4 and Table 9 of this edition);

  • GB/T 12202007

    2

    For 30Cr13(Y3Cr13) steel, its percentage elongation after fracture is adjusted from 12% and 40% to 8% and 35% (Table 4 of 1992 edition; Table 9 of this edition);

    The original yield strength 0.2 value for some martensite steels (No. 18, 22, 26, 39, 46, 50 and 52) and 06Cr13Al(0Cr13Al) is adjusted from 177Mpa to proof strength at non-proportional extension RP0.2 value to be 175 N/mm2 (Table 3 of 1992 edition; Table 6 and Table 8 of this edition);

    The yield strength 0.2 value for 022Cr12(00Cr12) steels is adjusted from 196MPa to proof strength at non-proportional extension RP0.2 value to be 195 N/mm2, while tensile strength is adjusted from 365MPa to 360N/mm2 (Table 3 of 1992 edition; Table 8 of this edition);

    The tensile strengths Rm for 20Cr13 (2Cr13) and 13Cr13 (1Cr13Mo) are adjusted respectively from 635MPa and 685MPa to 640N/mm2 and 690N/mm2 (Table 4 of 1992 edition; Table 9 of this edition);

    It has cancelled the stipulations on section shrinkage rate of flat steel (Table 3 ~ Table 5 of 1992 edition; notes of Table 6 to Table 10 of this edition);

    Corrosion resistance is changed to an item in agreement, where it has cancelled the two test methods contained in GB/T 4334.4 and GB/T 4334.6, while for the test condition of 06Cr19Ni13Mo3 (0Cr19Ni13Mo3) it has added Sensitizing treatment (Article 5.5 of 1992 edition; Article 7.5 of this edition);

    For Surface quality it has added that It may specify to remove scales formed from heat treatment by way of pickling, turning or other methods through negotiations between the Supplier and the Buyer, which should be indicated in contract (Article 5.8 of 1992 edition; Article 7.8 of this edition);

    It has clearly specified the sampling positions in Macro strcture and Tower shape for inspection of continuous casting steel and the sampling quantity for Corrosion resistance test (Article 12 of 1992 edition; Article 16 of this edition);

    It has cancelled Check list for stainless steel grades of this Standard and stainless steel grades of each country and changed to direct quotation of GB/T 20878: Stainless steel and heat-resisting steel Grade and chemical compositions (Appendix B of 1992 edition; Table 1 ~ Table 5 of this edition).

    The Appendix A and Appendix B of this Standard are informative appendixes. This Standard is proposed by China Iron and Steel Association. This Standard is governed by National Technical Committee of Standardization for Iron and Steel. The main drafting units of this Standard include China Metallurgical Information and Standardization Institute and Liaoning Dongbei Special Steel Group Co., Ltd.. The major drafters of this Standard include Luan Yan, Dai Qiang, Gu Qiang, Zeng Wentao and Liu Baoshi. Versions issued in history to be substituted by this Standard include: ---------GB/T 12201975, GB/T 12201984, GB/T 12201992.

  • GB/T 12202007

    1

    Contents 1. Scope.........................................................................................................................................1 2. Normative documents quoted ...................................................................................................1 3. Technical terms and definitions ................................................................................................4 4. Contents in order sheet..............................................................................................................4 5. Classification.............................................................................................................................4 6. Dimension, contour, weight and permissible tolerance.............................................................4 7. Technical requirements .............................................................................................................5 8. Test methods ...........................................................................................................................21 9. Inspection rules .......................................................................................................................22 10. Packing, marking and quality certificate.............................................................................22 Appendix A ....................................................................................................................................23 (Informative appendix) ...................................................................................................................23 Typical heat treatment regulations for stainless steel bars or test pieces .................................23 Appendix B ....................................................................................................................................27 (Informative appendix) ...................................................................................................................27

  • GB/T 12202007

    1

    1. Scope This Standard has stipulated the dimensions, contour, technical requirements , test methods, inspection rules, packing marks and certificate quality, etc, of stainless steel bars (generic terms of round steel, square steel, flat steel, hexagonal steel and octagonal steel, hereinafter refer to as Steel bar). This Standard is applicable to the hot rolled and forged steel bars that the dimension (diameter, side length, thickness or subtense distance, hereinafter refer to as Dimension) is no more than 250mm. Through negotiations of both the Supplier and Buyer, it may also supply the hot rolled and forged steel bars that the dimension is more than 250mm.

    2. Normative documents quoted Articles contained in the following documents have become articles of this Standard after

    they are quoted. For the dated documents so quoted, all their modifications made thereafter (excluding corrections) or revised versions shall not be applicable to this Standard, but all parties who have reached agreements on the basis of this Standard are encouraged to study on the implementation of the latest versions of these document. For the undated documents so quoted, their latest versions shall be applicable to this Standard. GB/T 222 Permissible tolerances for chemical composition of steel products GB/T 223.3 Methods for chemical analysis of iron, steel and alloy - The Diantipyrylmethane

    Phosphomolybdate Gravimetric Method for the Determination of phosphonium content GB/T 223.4 Methods for chemical analysis of iron, steel and alloy - The volumetric method

    for determination of manganese content by ammonium nitrate oxidation GB/T 223.5 Methods for chemical analysis of iron, steel and alloy The reduction type

    silicomolybdic acid spectrophotometric method for the determination of acid-soluble silicon content

    GB/T 223.8 Methods for chemical analysis of iron, steel and alloy The sodium fluoride separation-EDTA titration method for the determination of aluminium content

    GB/T 223.9 Methods for chemical analysis of iron, steel and alloy The chromazurine S spectrophotometric method for the determination of aluminium content

    GB/T 223.11 Methods for chemical analysis of iron, steel and alloy The ammonium persulphate oxidation volumetric method for the determination of chrome content

    GB/T 223.14 Methods for chemical analysis of iron, steel and alloy The tantalum reagent extraction spectrophotometric method for the determination of vanadium content

    GB/T 223.16 Methods for chemical analysis of iron, steel and alloy The chromotropic acid spectrophotometric method for the determination of titanium content

    GB/T 223.17 Methods for chemical analysis of iron, steel and alloy The diantipyrylmethane spectrophotometric method for the determination of titanium content

    GB/T 223.18 Methods for chemical analysis of iron, steel and alloy The sodium thiosulfate separation - iodine volumetric method for the determination of cuprum content

    GB/T 223.23 Methods for chemical analysis of iron, steel and alloy The dimethyl glyoxime spectrophotometric method for the determination of nickel content

    GB/T 223.25 Methods for chemical analysis of iron, steel and alloy The dimethyl glyoxime gravimetric method for the determination of nickel content

    GB/T 223.26 Methods for chemical analysis of iron, steel and alloy The thiocyanate direct spectrophotometric method for the determination of molybdenum content

  • GB/T 12202007

    2

    GB/T 223.28 Methods for chemical analysis of iron, steel and alloy The alpha-Benzoin oxim gravimetric method for the determination of molybdenum content

    GB/T 223.36 Methods for chemical analysis of iron, steel and alloy The distillation separation - neutralization titration method for the determination of nitrogen content

    GB/T 223.37 Methods for chemical analysis of iron, steel and alloy The distillation separation - indophenol blue spectrophotometric method for the determination of nitrogen content

    GB/T 223.40 Determination of niobium content in iron, steel and alloy The sulfochlorophenol S spectrophotometric method

    GB/T 223.52 Methods for chemical analysis of iron, steel and alloy The hydroxylamine hydrochloride - iodine gravimetric method for the determination of selenium content

    GB/T 223.58 Methods for chemical analysis of iron, steel and alloy The sodium arsenite - sodium nitrite titration method for the determination of manganese content

    GB/T 223.59 Methods for chemical analysis of iron, steel and alloy The molybdenum blue photometric method for the determination of phosphonium content

    GB/T 223.60 Methods for chemical analysis of iron, steel and alloy The perchloric acid dehydration method for the determination of silicon content

    GB/T 223.61 Methods for chemical analysis of iron, steel and alloy The ammonium phosphomolybdate volumetric method for the determination of phosphonium content

    GB/T 223.62 Methods for chemical analysis of iron, steel and alloy The Butyl Acetate extraction photometric method for the determination of phosphonium content

    GB/T 223.63 Methods for chemical analysis of iron, steel and alloy The sodium periodate (potassium periodate) photometric method for the determination of manganese content (GB/T 223.63 1998, neq ISO R 629)

    GB/T 223.64 Methods for chemical analysis of iron, steel and alloy The flame atom absorption spectral method for the determination of manganese content

    GB/T 223.67 Methods for chemical analysis of iron, steel and alloy The potassium iodate titration method after combustion in the pipe furnace for determination of phosphonium content

    GB/T 223.68 Methods for chemical analysis of iron, steel and alloy The gas volumetric method after combustion in the pipe furnace for determination of carbon content

    GB/T 223.71 Methods for chemical analysis of iron, steel and alloy The gravimetric method after combustion in the pipe furnace for determination of carbon content

    GB/T 223.72 Methods for chemical analysis of iron, steel and alloy The aluminium oxide color layer separation - barium sulfate gravimetric method for determination of phosphonium content

    GB/T 226 Etch test for macrostructure and defect of steels (GB/T 226 1991, neq ISO4969: 1980, Steel Macroscopic examination by etching with strong mineral adids)

    GB/T 228 Metallic material Greenhouse tension test method (GB/T 228 2002, eqv ISO 6892: 1998)

    GB/T 229 Metal Charpy impact test method (GB/T 229 1994, eqv ISO 83: 1976, Steel Charpy impact test (U-notch), eqv ISO 148; 1983, Steel Charpy impact test (V-notch))

    GB/T 230.1 Metal Rockwell hardness test, Part I: Test method (A, B, C, D, E, F, G, H, K, N,

    T measuring scales) (GB/T 230.1 2004, ISO 6508: 1999, MOD) GB/T 231.1 Metal Brinell hardness test, Part I: Test method (GB/T 231.1 2002, eqv ISO

  • GB/T 12202007

    3

    6506-1: 1999) GB/T 7022004 Metal Hot-rolled round steel and square steel Dimension, contour,

    weight and permissible tolerance (GB/T 7022004, ISO 1035-1: 1980, Hot-rolled steel bar Part 1: Dimension of round bars, ISO1035-2: 1980, Hot-rolled steel bar Part 1: Dimension of square bars, ISO1035-4: 1982, Hot-rolled steel bar Part 4:Tolerances, MOD)

    GB/T 7041988 Metal Hot-rolled flat steel Dimension, contour, weight and permissible tolerance

    GB/T 7051985 Metal Hot-rolled hexagonal steel and octagonal steel Dimension, contour, weight and permissible tolerance

    GB/T 9081987 Metal Forged round steel and square steel Dimension, contour, weight and permissible tolerance

    GB/T 1979 Standard diagrams for macrostructure and defect of structural steels GB/T 2101 General requirements of acceptance, packaging, marking and certification for

    section steel GB/T 2975 Steel and steel products--Location and preparation of test pieces for mechanical

    testing (GB/T 2975 1998, eqv ISO 377: 1997) GB/T 4334.1 Stainless steel 10% oxalic acid etch test method GB/T 4334.2 Stainless steel sulfuric acid - ferric sulfate corrosion test method GB/T 4334.3 Stainless steel 65% nitric acid corrosion test method GB/T 4334.5 Stainless steel sulfuric acid - copper sulfate corrosion test method GB/T 4340.1 Metal Vickers hardness test, Part I: Test method (GB/T 4340.1 1999, eqv

    ISO 6507-1: 1997) GB/T 6394 Metal Methods for determination of the average grain size GB/T 6401 1986 Micrographic method for determining area fraction of the alpha-phases

    using charts in ferritic-austenitic duplex stainless steel GB/T 7736 Ultrasonic inspecting method for macro-structure and defect of steel GB/T 9971 2004 Pure iron for raw material GB/T 10121 Steel products--Method for magnetic particle inspection of tower sample GB/T 10561 Determination of nonmetal inclusion content in steels -- Methods for

    radiographic inspection and classification of radiographs (GB/T 10561 2005, ISO 4967: 1998, IDT)

    GB/T 11170 Method for photoelectric emission spectral analysis of stainless steel GB/T 13305 1991 Micrographic method for determining area fraction of the alpha-phases

    in austenitic stainless steel GB/T 15574 Classification for steel products GB/T 15711 Steel productsMethod for etch test of tower sample GB/T 16761 1997 Forged flat steel Dimension, contour, weight and permissible tolerance GB/T 17505 General technical requirements on delivery of steel and steel products (GB/T

    17505 1998, eqv ISO 404: 1992) GB/T 20066 Iron and steel Sampling and sample preparation method for determination of

    chemical compositions (GB/T 20066 2006, ISO 14284: 1996, IDT) GB/T 20878 Stainless steel and heat-resisting steel Grades and chemical compositions YB/T 5293 Metallic materials-Forging test

  • GB/T 12202007

    4

    3. Technical terms and definitions The technical terms and definitions established in GB/T 20878 and GB/T 15574 are applicable to this Standard.

    4. Contents in order sheet The contract for goods or order form made according this Standard shall contain the following contents: a) Standard code; b) Product description; c) Grade or unified numerical code; d) Section shape (round, square, flat, hexagonal or octagonal); e) Dimensions and contour (see Chapter 6 hereof); f) Weight (or quantity); g) Processing method used (See 5.2 hereof); h) Delivery state (See 7.2 hereof); i) Special requirements (See 7.9 hereof).

    5. Classification 5.1 By structural features, steel bars are divided into five categories, including austenite type,

    austenite ferrite type, ferrite type, martensite type and precipitation-hardening type. 5.2 By application methods, steel bars are divided into two categories. Application methods of

    steel bars should be indicated in contract, otherwise, it shall supply the steel for the purpose of cutting processing.

    a) Steel for pressing processing UP 1) Hot-pressing processing UHP 2) Steel for hot-forging UHF 3) Blank for cold drawing UCD

    b) Steel for cutting processing UC 6. Dimension, contour, weight and permissible tolerance 6.1 Dimension, contour, weight and permissible tolerance of hot-rolled round steel and square

    steel The dimension, contour, weight and permissible tolerance of hot-rolled round steel and square steel shall conform to the stipulations set forth in GB/T 702 2004, the concrete requirements of which should be indicated in contract. Otherwise it shall execute the second group contained in GB/T 802 2004 Standard.

    6.2 Dimension, contour, weight and permissible tolerance of hot-rolled flat steel The dimension, contour, weight and permissible tolerance of hot-rolled flat steel shall conform to the stipulations set forth in GB/T 704 1988, the concrete requirements of which should be indicated in contract. Otherwise it shall execute the contract according to the common class as specified in GB/T 704 1998.

    6.3 Dimension, contour, weight and permissible tolerance of hot-rolled hexagonal steel and octagonal steel

  • GB/T 12202007

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    The dimension, contour, weight and permissible tolerance of hot-rolled hexagonal steel and octagonal steel shall conform to the stipulations set forth in GB/T 705 1985, the concrete requirements of which should be indicated in contract. Otherwise it shall execute the contract according to the second group as specified in GB/T 705 1985.

    6.4 Dimension, contour, weight and permissible tolerance of forged round steel and square steel The dimension, contour, weight and permissible tolerance of forged round steel and square steel shall conform to the stipulations set forth in GB/T 908 1987, the concrete requirements of which should be indicated in contract. Otherwise it shall execute the contract according to the second group as specified in GB/T 908 1987.

    6.5 Dimension, contour, weight and permissible tolerance of forged flat steel The dimension, contour, weight and permissible tolerance of forged flat steel shall conform to the stipulations set forth in GB/T 16761 1997, the concrete requirements of which should be indicated in contract. Otherwise it shall execute the contract according to the second group as specified in GB/T 16761 1997.

    6.6 Weight Steel bars shall be delivered by actual weight.

    7. Technical requirements 7.1 Grade and chemical components 7.1.1 Steel grades, unified numerical code and chemical compositions (melting analysis) shall

    conform to the stipulations set forth in Table 1 ~ Table 5 hereof. 7.1.2 The permissible tolerance for chemical compositions of steel bars shall conform to the

    stipulations set forth in GB/T 222. 7.2 Melting method

    Unless it is otherwise stipulated in contract, it shall usually adopt initial molten steel plus out-of-furnace refining process.

    7.3 Delivery state Steel bars can be delivered in heat-treated or non-heat-treated state and the order can select delivery state with reference to Articles 7.3.1 ~ 7.3.4 hereof, which should be indicated in contract. Otherwise, it shall deliver non-heat-treated steels. The regulations for heat treatment of all kinds of steel bars refer to Table A.1 ~ Table A.5 in Appendix A hereof.

    7.3.1 Austenite type and austenite ferrite type steel bars for cutting processing shall go through solution treatment, which can be omitted through negotiations by both the Supplier and Buyer. The steel bars for hot-pressing processing shall not go through solution treatment.

    7.3.2 Ferrite type steel bars shall go through annealing treatment, which can be omitted through negotiations by both the Supplier and Buyer.

    7.3.3 Martensite type steel bars shall go through annealing treatment. 7.3.4 Precipitation-hardening type steel bars can select solution treatment or annealing

    treatment based on steel texture, annealing regulation shall be determined by the negotiations of both Supplier and Buyer, if there is no agreement, the annealing temperature shall usually be 650 ~ 680. Precipitation-hardening type steel bars (excluding 05Cr17Ni4Cu4Nb) may not be treated through negotiations of both Supplier and Buyer.

  • GB/T 12202007

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    7.4 Mechanical properties 7.4.1 The heat treatment regulations for all kinds of steel bars of test pieces shall refer to the

    stipulations set forth in Table A.1 ~ Table A.5 of Appendix A hereof. The dimension of test piece blank for heat treatment shall usually be 25mm. When the dimension of steel bar is less than 25mm, heat treatment shall be conducted on original dimension steel bars.

    7.4.2 For the heat-treated steel bars (except for martensite steel subject to annealing), test pieces shall be no longer heat treated and its mechanical properties shall conform to the stipulations set forth in Table 6 ~ Table 10 hereof respectively.

    7.4.3 For the non-heat-treated steel bars, the blank of test pieces shall be heat treated and its mechanical properties shall conform to the stipulations set forth in Table 6 ~ Table 10 hereof respectively.

    7.4.4 The mechanical properties of precipitation-hardening type steel bars shall be indicated in contract, otherwise it shall execute the second group in contract.

    7.4.5 If the Supplier can guarantee the qualification of mechanical properties, it may wholly or partially omit mechanical property test.

  • GB/T 12202007

    7

    Table 1 Chemical compositions of austenite type stainless steel Chemical compositions (mass fraction) % Code

    in GB/T 20878

    Unified numerical code

    New grade Original grade

    C Si Mn P S Ni Cr Mo Cu N Other elements

    1

    3

    9

    13

    15

    16

    17

    18

    22

    23

    24

    25

    26

    32

    35

    38

  • GB/T 12202007

    8

    Table 1 (Continued)

    Chemical compositions (mass fraction) % Code in GB/T 20878

    Unified numerical code

    New grade Original grade

    C Si Mn P S Ni Cr Mo Cu N Other elements

    Note 1: All the elements listed in the table shall be maximum value, unless it is otherwise indicated for range or minimum value. Value in bracket is the maximum value to put in or permissible content. Note 2: The comparison between the grades of this Standard and those of foreign standards refer to GB/T 20878.

    a It may add the alloy elements other than this table, if necessary.

  • GB/T 12202007

    9

    Table 2 Chemical compositions of austenite-ferrite type stainless steel Chemical compositions (mass fraction) % Code in

    GB/T 20878

    Unified numerical code

    New grade Original grade

    C Si Mn P S Ni Cr Mo Cu N Other elements

    Note 1: All the elements listed in the table shall be maximum value, unless it is otherwise indicated for range or minimum value. Note 2: The comparison between the grades of this Standard and those of foreign standards refer to GB/T 20878.

  • GB/T 12202007

    10

    Table 3 Chemical compositions of ferrite type stainless steel Chemical compositions (mass fraction) % Code in GB/T 20878 Unified numerical

    code

    New grade Original

    grade C Si Mn P S Ni Cr Mo Cu N Other elements

    Note 1: All the elements listed in the table shall be maximum value, unless it is otherwise indicated for range or minimum value. Value in bracket is the maximum value to put in or permissible content Note 2: The comparison between the grades of this Standard and those of foreign standards refer to GB/T 20878. a It is permissible for nickel content to be less than or equal to 0.50%, copper content to be less than or equal to 0.20%, while Ni + Cu0.50%m, and it may add the alloy elements other than this table, if necessary.

  • GB/T 12202007

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    Table 4 Chemical compositions of Martensite type stainless steel Chemical compositions (mass fraction) % Code in

    GB/T 20878 Unified numerical code

    New grade Original

    grade C Si Mn P S Ni Cr Mo Cu N Other elements

    Note 1: All the elements listed in the table shall be maximum value, unless it is otherwise indicated for range or minimum value. Value in bracket is the maximum value to put in or permissible content Note 2: The comparison between the grades of this Standard and those of foreign standards refer to GB/T 20878. a The grade of adjusted compositions relative to GB/T 20878.

  • GB/T 12202007

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    Table 5 Chemical compositions of precipitation-hardening type stainless steel

    Chemical compositions (mass fraction) % Code in GB/T 20878 Unified numerical code New grade Original grade

    C Si Mn P S Ni Cr Mo Cu N Other elements

    Note 1: All the elements listed in the table shall be maximum value, unless it is otherwise indicated for range or minimum value. Note 2: The comparison between the grades of this Standard and those of foreign standards refer to GB/T 20878.

  • GB/T 12202007

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    Table 6 Mechanical properties of austenite type steel bars or test pieces through solution treatment (See Table A.1) Hardness b Proof

    strength, non-proporti

    onal extension

    RP0.2b/(N/mm2)

    Tensile strength Rm

    /(N/mm2)

    Shrinkage rate after fracture A /%

    Section shrinkage rate

    Zc /%

    HBW HRB HV Code in GB/T

    20878 Unified numerical code

    New grade Original grade

    No less than No more than

  • GB/T 12202007

    14

    Table 6 (Continued) Hardness b Proof strength,

    non-proportional extension

    RP0.2b/(N/mm2)

    Tensile strength Rm /(N/mm2)

    Shrinkage rate after fracture A

    /%

    Section shrinkage rate Zc

    /% HBW HRB HV

    Code in GB/T 20878

    Unified numerical

    code

    New

    grade

    Original grade

    No less than No larger than

    a. This table is only applicable to the steel bars that the diameter, side length, thickness or subtense distance is less than or equal to 180mm, for the steel bars of more than 180mm, it can be forged into 180mm sample blank for test, or through negotiation of the Supplier and Buyer to stipulate that it is allowable to reduce the value of its mechanical properties.

    b. Proof strength, non-proportional extension and hardness shall only be tested when it is required by the Buyer (to be indicated in contract), in this case, the Supplier can select one method to determine hardness according to the dimension and state of steel bars.

    c. It is not applicable to flat steel, but when it is required by the Buyer, it shall be decided through negotiation of both the Supplier and Buyer.

  • GB/T 12202007

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    Table 7 Mechanical properties of austenite-ferrite type steel bars or test pieces through solution treatment (See Table A.2) Hardness b Proof strength,

    non-proportional extension

    RP0.2b/(N/mm2)

    Tensile strength Rm

    /(N/mm2)

    Shrinkage rate after fracture A

    /%

    Section shrinkage rate Zc

    /% HBW HRB HV

    Code in GB/T 20878

    Unified numerical code

    New grade Original grade

    No less than No more than

    a. Table 7 is only applicable to the steel bars that the diameter, side length, thickness or subtense distance is less than or equal to 75mm, for the steel bars of more than 75mm, it can be forged into 75mm sample blank for test, or through negotiation of the Supplier and Buyer to stipulate that it is allowable to reduce the value of its mechanical properties.

    b. Proof strength, non-proportional extension and hardness shall only be tested when it is required by the Buyer (to be indicated in contract), in this case, the Supplier can select one method to determine hardness according to the dimension and state of steel bars.

    c. It is not applicable to flat steel, but when it is required by the Buyer, it shall be decided through negotiation of both the Supplier and Buyer. d. For the round steel, hexagonal steel and octagonal steel that diameter or subtense distance is less than or equal to 16mm, or for the square steel and flat steel that the thickness is less than 12mm, it shall not conduct impact test.

  • GB/T 12202007

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    Table 8 Mechanical properties of ferrite type steel bars or test pieces through annealing treatment (See Table A.3)a Hardness b Proof strength,

    non-proportional extension

    RP0.2b/(N/mm2)

    Tensile strength Rm /(N/mm2)

    Shrinkage rate after fracture A

    /%

    Section shrinkage rate Zc

    /% HBW HRB

    HV

    Code in

    GB/T 20878

    Unified numerical code

    New grade Original grade

    No less than No more than

    78 S11348 06Cr13A1 0Cr13A1 175 410 20 60 78 183 83 S11203 022Cr12 00Cr12 195 360 22 60 -- 183 85 S11710 10Cr17 1Cr17 205 450 22 50 -- 183 86 S11717 Y10Cr17 Y1Cr17 205 450 22 50 -- 183 88 S11790 10Cr17Mo 1Cr17Mo 205 450 22 50 -- 183 94 S12791 008Cr27Mo 00Cr27Mo 245 410 20 45 -- 183 95 S13091 008Cr30Mo2 00Cr30M02 295 450 20 45 183

    a. Table 7 is only applicable to the steel bars that the diameter, side length, thickness or subtense distance is less than or equal to 75mm, for the steel bars of more than 75mm, it can be forged into 75mm sample blank for test, or through negotiation of the Supplier and Buyer to stipulate that it is allowable to reduce the value of its mechanical properties.

    b. Proof strength, non-proportional extension and hardness shall only be tested when it is required by the Buyer (to be indicated in contract), in this case, the Supplier can select one method to determine hardness according to the dimension and state of steel bars.

    c. It is not applicable to flat steel, but when it is required by the Buyer, it shall be decided through negotiation of both the Supplier and Buyer. d. For the round steel, hexagonal steel and octagonal steel that diameter or subtense distance is less than or equal to 16mm, or for the square steel and flat steel that the thickness is less than 12mm, it shall not conduct impact

    test.

  • GB/T 12202007

    17

    Table 9 Mechanical properties of Martensite type steel bars or test pieces through heat treatment a Mechanical property of test piece through quench tempering (See Table A.4) Hardness

    of annealed steel bars

    Proof strength, non-proportional

    extension RP0.2b/(N/mm2)

    Tensile strength Rm /(N/mm2)

    Shrinkage rate after fracture A

    /% Section

    shrinkage rate Zb/%

    Charpy absorbed energy Aku2d/J

    HBW HEC HBW

    Code in

    GB/T 20878

    Unified numerical code

    New grade Original grade

    Group

    No less than No more than

    96 S40130 12Cr12 1Cr12 390 590 25 55 118 170 -- 200 97 S41008 06Cr13 0Cr13 345 490 24 60 -- -- 183 98 S41010 12Cr13 1Cr13 345 540 22 55 78 159 200

    100 S41617 Y12Cr13 Y1Cr13 345 540 17 45 55 159 200 101 S42020 20Cr13 2Cr13 440 640 20 50 63 192 223 102 S42030 30Cr13 3Cr13 540 735 12 40 24 217 235 103 S42037 Y30Cr13 Y3Cr13 540 735 8 35 24 217 235 104 S42040 40Cr13 4Cr13 -- 50 235 106 S43110 14Cr17Ni2 1Cr17Ni2 -- 1080 10 285 107 S43120 17Cr16Ni2* 1 700 900~1050 12 45 25 (Agv) 295 108 S44070 68Cr17 7Cr17 2 600 800~950 14 255 109 S44080 85Cr17 8Cr17 -- -- -- 54 255 110 S44096 108Cr17 11Cr17 -- -- -- 56 269 111 S44097 Y108Cr17 Y11Cr17 -- ---- -- 58 269 112 S44090 95Cr18 9Cr18 -- 55 255 115 S45710 13Cr13Mo 1Cr13Mo 490 690 20 60 78 192 -- 200 116 S45830 32Cr13Mo 3Cr13Mo -- -- -- 50 207 117 S45990 102Cr17Mo 9Cr18Mo -- -- -- 55 269 118 S46990 90Cr18MoV 9Cr18MoV -- -- -- 55 269

    a. Table 9 is only applicable to the steel bars that the diameter, side length, thickness or subtense distance is less than or equal to 75mm, for the steel bars of more than 75mm, it can be forged into 75mm sample blank for test, or through negotiation of the Supplier and Buyer to stipulate that it is allowable to reduce the value of its mechanical properties.

    b. It is not applicable to flat steel, but when it is required by the Buyer, it shall be decided through negotiation of both the Supplier and Buyer. c. For annealing by 750, the hardness is to be decided through negotiation of the Supplier and Buyer. d. For the round steel, hexagonal steel and octagonal steel that diameter or subtense distance is less than or equal to 16mm, or for the square steel and flat steel that the thickness is less than 12mm, it shall not conduct impact test. e. The property group of 17Cr16Ni2 steel shall be indicated in contract, otherwise it shall be selected by the Supplier himself.

  • GB/T 12202007

    18

    Table 10 Mechanical properties of precipitation-hardening type (See Table A.5) steel bars or test pieces Hardness c Heat treatment Proof strength, non-proportional

    extension RP0.2b/(N/mm2)

    Tensile strength Rm /(N/mm2)

    Shrinkage rate after fracture A

    /% Section

    shrinkage rate Zb/%

    Code in

    GB/T 20878

    Unified numerical code

    New grade Original grade

    Type Group NO LESS THAN

    HBW

    HRW

    Solution treatment

    0 -- -- -- -- 363 38 480 aging

    1 1180 1310 10 35 375 40 550 aging

    2 1000 1070 12 45 331 35 580 aging

    3 865 1000 13 45 302 31

    136

    S51550

    05Cr15Ni5Cu4Nb

    Precipitation hardening

    620 aging

    4 725 930 16 50 277 28 Solution treatment

    0 -- -- -- -- 363 38 480 aging

    1 1180 1310 10 40 375 40 550 aging

    2 1000 1070 12 45 331 35 580 aging

    3 865 1000 13 45 302 31

    137

    S51740

    05Cr17Ni4Cu4Nb

    0Cr17Ni4Cu4Nb

    Precipitation hardening

    620 aging

    4 725 930 16 50 277 28 Solution treatment

    0 380 1030 20 -- 229 -- 510 aging

    1

    1030 1230 4 10 388 --

    138

    S51770

    07Cr17Ni7A1

    0Cr17Ni7A1

    Precipitation hardening

    565 aging

    2

    960 1140 5 25 363 --

    Solution treatment

    0 -- -- -- -- 269 -- 510 aging

    1

    1210 1320 6 20 388 --

    139

    S51570

    07Cr15Ni7Mo2A1

    0Cr15Ni7Mo2A1

    Precipitation hardening

    565 aging

    2

    1100 1210 7 25 375 --

    a. Table 10 is only applicable to the steel bars that the diameter, side length, thickness or subtense distance is less than or equal to 75mm, for the steel bars of more than 75mm, it can be forged into 75mm sample blank for test, or through negotiation of the Supplier and Buyer to stipulate that it is allowable to reduce the value of its mechanical properties.

    b. It is not applicable to flat steel, but when it is required by the Buyer, it shall be decided through negotiation of both the Supplier and Buyer. c. The Supplier can select one method to determine hardness according to the dimension and state of steel bars

  • GB/T 12202007

    19

    7.5 Corrosion resistance

    It may conduct intercrystalline corrosion test on austenite type and austenite-ferrite type stainless steel bars, as it is required by the Buyer, with the proper test method decided through negotiations of both the Supplier and Buyer, which should be indicated in contract, the corrosion resistance of which refers to Table 11 and Table 12 hereof. The corrosion resistance for the steel bars other than the grades listed in Table 11 and Table 12 shall be determined through negotiations of both the Supplier and Buyer.

    Table 11 Determination for 10% oxalic acid corrosion test in GB/T 4334.1 Code

    in GB/T 20878

    Unified numerical

    code

    New grade

    Original grade

    Test state

    GB/T 4334.2 sulfuric

    acid - ferric sulfate

    corrosion test

    GB/T 4334.3

    65% nitric acid

    corrosion test

    GB/T 4334.5 sulfuric acid - copper sulfate

    corrosion test

    17 S30408 06Cr19Ni10 0Cr18Ni9 Channel texture

    Depression texture II

    38 S31608 06Cr17Ni12Mo2 0Cr18Ni9 45 S31688 06Cr18Ni12Mo2Cu2 0Cr17Ni12Mo2 49 S31708 06Cr19Ni13Mo3* 0Cr18Ni12Mo2Cu2

    Solution treatm

    ent

    Channel texture

    Channel texture

    18 S30403 022Cr19Ni10 00Cr19Ni10 Channel texture

    Depression texture II

    39 S31603 022Cr17Ni12Mo2 00Cr17Ni14Mo2 46 S31683 022Cr18Ni14Mo2Cu2 00Cr18Ni14Mo2Cu250 S31703 022Cr19Ni13Mo3 00Cr19Ni13Mo3

    Channel texture

    55 S32168 06Cr18Ni11Ti 0Cr18Ni10Ti 62 S34778 06Cr18Ni11Nb 0Cr18Ni11Nb

    sensitizing treatm

    ent

    ---

    Channel texture

    a It may conduct sensitizing treatment, but it shall be determined through negotiations of both the Supplier and Buyer before test.

    Table 12 Intercrystalline corrosion test

    GB/T 4334.2

    GB/T 4334.3

    GB/T 4334.5

    Code in GB/

    T 2087

    8

    Unified numeri

    cal code

    New grade

    Original grade

    Test

    state

    Weight loss by corrosio

    n [g/(m2.h

    )]

    Test state

    Weight loss by corrosio

    n [g/(m2.h

    )]

    Test

    state

    State of curved surface

    under test

    17 S30408

    06Cr19Ni10 0Cr18Ni9 Solution treatme

    nt

    agreement

    38 S31608

    06Cr17Ni12Mo2 0Cr17Ni12Mo2

    45 S31688

    06Cr18Ni12Mo2Cu2

    0Cr18Ni12Mo2Cu2

    49 S31708

    06Cr19Ni13Mo3* 0Cr19Ni13Mo3*

    Solution treatment

    agreement

    Solution treatment

    sensitizing

    treatment

    agreement

    18 S30403

    022Cr19Ni10 00Cr19Ni10

    39 S31603

    022Cr17Ni12Mo2 00Cr17Ni14Mo2

    46 S31683

    022Cr18Ni14Mo2Cu2

    00Cr18Ni14Mo2Cu2

    50 S31703

    022Cr19Ni13Mo3 00Cr19Ni13Mo3

    sensitizing treatment

    agreement

    41 S31668

    06Cr17Ni12Mo2Ti

    0Cr18NNi12Mo3Ti

    sensitizing treatment

    No Intercrystall

    ine corrosion crack is allowed

  • GB/T 12202007

    20

    55 S32168

    06Cr18Ni11Ti 0Cr18Ni10Ti

    62 S34778

    06Cr18Ni11Nb 0Cr18Ni11Nb a It may conduct sensitizing treatment, but it shall be determined through negotiations of both the Supplier and Buyer before test.

    7.6 Macro structure 7.6.1 The acid dip macroscopic test piece of steel bar shall have no visible shrinkage cavity, air

    bubble, crack, inclusion, skull patch or shatter crack. It is permissible for steel bars for cutting processing to have subsurface inclusion or other inclusion with depth to be no more than half of nominal dimension tolerance.

    7.6.2 The qualification level for acid dip macro structure shall conform to the stipulations set forth in Table 13 hereof. When the Buyer requires group 1, it should be indicated in contract. For steel bars with dimension no more than 200mm, the qualification level for macro structure shall be decided through negotiations of the two parties.

    7.6.3 If it can be guaranteed by the Supplier, it is permissible to apply ultrasonic detection or other nondestructive flaw detection methods in place of macro structure inspection.

    Table 13 Macro structure qualification level Group Common porosity Center porosity Ingot type segregation

    Group 1 Level 2 Level 2 Level 2 Group 2 Level 3 Level 3 Level 3

    7.7 Hot forging 7.7.1 Steel for hot heading upsetting (to be indicated in contract) shall be subject to hot forging

    test to forge test piece to one third of the original height without crack or breach on the surface.

    7.7.2 This test can be omitted for steel bar with dimension to be more than 80mm if the Supplier can guarantee the qualification of forging test.

    7.8 Surface quality 7.8.1 The surface of steel bars for pressing processing shall have no crack, scab, fold or

    inclusion on surface, otherwise, the defects mentioned above must be eliminated. The depth for such elimination shall conform to the stipulation in Table 14 hereof and the width should be no less than 5 times of depth, while the maximum elimination depth on the same cross section shall be no more than one and it is permissible for individual scratches, impressions or pockmarks whose size is no more than half of nominal dimension counting from actual dimension, or the minor cracks with depth to be no more than 0.20mm to exist on surface. Based on the agreement of the Supplier and Buyer, the surface of steel bars for cutting processing can be turned or peeled.

    Table 14 Permissible depth for defect elimination on the surface of steel bars for pressing

    processing purpose Nominal dimension of steel bars/mm Permissible depth of elimination

    80 Half of nominal dimension tolerance of steel bars > 80 ~ 140 Nominal dimension tolerance of steel bars

    > 140 ~ 200 5% of nominal dimension of steel bars

  • GB/T 12202007

    21

    > 200 ~ 250 6% of nominal dimension of steel bars

    7.8.2 It is permissible for steel bars for cutting processing to have local defects no more than

    stipulations counting from nominal dimension as set forth in Table 15 hereof. Table 15 Permissible depth for local defects on the surface of steel bars for cutting processing

    Nominal dimension of steel bars/mm Permissible depth of local defects

    < 100 Negative deviation of nominal dimension of steel bars

    100 Nominal dimension tolerance of steel bars 7.8.3 It can remove the scale produced by heat treatment by pickling, turning or other methods

    through negotiations of both the Supplier and Buyer, which should be indicated in contract.

    7.9 Special requirements Steel bars can be supplied by the following special requirements as requested by the Buyer and with agreement reached by both the Supplier and Buyer.

    a) Reduce the range of chemical compositions as listed in Table 1 ~ Table 5; b) Restrict the upper limit of tensile strength as listed in Table 6 ~ Table 10; c) Add the test on corrosion resistance; d) Check alpha phase content; e) Check nonmetallic inclusion content in steel; f) Check grain size of steel; g) Add inspection with tower sample; h) Other special requirements.

    8. Test methods

    The inspection items and test methods for each lot of steel bars shall conform to the stipulations as set forth in Table 16 hereof. Table 16 Inspection item, sampling quantity, sampling position and test method for steel bars

    No. Inspection items Sampling quantitya Sampling position Test method 1 Chemical compositions 1 GB/T 20066 GB/T 223 (see Chapter 2), GB/T 11170,

    Appendix A of GB/T 9971-2004,

    2 Tensile 2 GB/T 228 3 Impact 2

    On different steel bars, GB/T 2975 GB/T 229

    4 Hardness 2 GB/T 230.1, GB/T 231.1, GB/T 4340.1 5 intercrystalline

    corrosion 2

    On different steel bars GB/T 4334.1, GB/T 4334.2, GB/T 4334.3,

    GB/T 4334.5

    6 Macro structure 2 different steel bars or blank equivalent to ingot head;

    on any of different steel bars for continuous cast steel

    GB/T 226, GB/T 1979

    7 Ultrasonic inspection

    2 On full piece of steel bar GB/T 7736

    8 Hot forging 2 YB/T 5293 9 Nonmetallic

    inclusion 2

    On different steel bars GB/T 10561

    10 Grain size 1 GB/T 6394 11 Alpha phase 1

    Any steel bar GB/T 6401 1986, GB/T 13305991

  • GB/T 12202007

    22

    12 Tower shape 2 different steel bars or blank equivalent to ingot head;

    on any of different steel bars for continuous cast steel

    GB/T 15711, GB/T 10121

    13 Dimension Piece by piece Calipers, micrometer caliper 14 Surface Piece by piece

    On full piece of steel bar Visual inspection

    In addition to surface and dimension inspections piece by piece, the sampling quantity for all the other inspection items of electroslag remelted steel shall be 1. When lot is organized by the consumable electrode melting mother furnace number, in addition to 1 sample taken from each electroslag furnace number for chemical compositions, the sampling quantity for other inspection items shall be the same as stipulations in this table.

    9. Inspection rules 9.1 Inspection and acceptance

    The inspection and acceptance of steel bars shall be conducted by the technical and quality control departments of the Supplier.

    9.2 Lot organization rules The inspection and acceptance of steel bars shall be carried out lot by lot. Each lot shall be

    composed of steel bars of the same grade, same furnace number, same processing method, same dimension and same delivery state (same furnace number of heat treatment). For the electroslag remelted steel, it is permissible to make delivery by the lot organized by the consumable electrode melting mother furnace number under the conditions that the process is stable and all technical requirements in this Standard can be guaranteed, which should be noted in certificate of quality.

    9.3 Sampling position and sampling quantity The sampling position and sampling quantity for each lot of steel bars shall conform to the stipulations set forth in Table 16 hereof.

    9.4 Rules for reinspection and determination 9.4.1 Rules for reinspection and determination shall execute the stipulations of GB/T 17505. 9.4.2 If the Supplier can guarantee the qualification of steel bars, it is permissible to use blank

    in place of product or use the large one in place of small one in the inspection results in connection with the mechanical property, macro structure and nonmetallic inclusion of steel bars or steel blanks from the same furnace number.

    10. Packing, marking and quality certificate

    The packing, marking and quality certificate shall conform to the stipulations of GB/T 2101.

  • GB/T 12202007

    23

    Appendix A (Informative appendix)

    Typical heat treatment regulations for stainless steel bars or test pieces

    Table A.1 Typical heat treatment regulations for austenite type stainless steel bars or test pieces

    Code in GB/T 20878

    Unified numerical code New grade Original grade Solution treatment/

    1 010 ~ 1 120, fast-cooling

    1 010 ~ 1 120, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 030 ~ 1 150, fast-cooling

    1 030 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 000 ~ 1 100, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    1 010 ~ 1 180, fast-cooling

    1 030 ~ 1 150, fast-cooling

    920 ~ 1 150, fast-cooling

    980 ~ 1 150, fast-cooling

    1 010 ~ 1 150, fast-cooling

    a When it is indicated in contract by the Buyer, it may conduct heat treatment, in this case, the heat treatment temperature shall be 850 ~ 930.

  • GB/T 12202007

    24

    Table A.2 Typical heat treatment regulations for austenite-ferrite type stainless steel bars or test pieces

    Code in GB/T 20878

    Unified numerical

    code New grade Original grade Solution treatment/

    67 S21860 14Cr18Ni11Si4A1Ti 1Cr18Ni11Si4A1Ti 930 ~ 1 050, fast-cooling

    68 S21953 022Cr19Ni5Mo3Si2N 00Cr18Ni5Mo3Si2 920 ~ 1 150, fast-cooling

    70 S22253 022Cr22Ni5Mo3N 950 ~ 1 200, fast-cooling

    71 S22053 022Cr23Ni6Mo3N 950 ~ 1 200, fast-cooling

    73 S22553 022Cr25Ni6Mo2N 950 ~ 1 200, fast-cooling

    75 S25554 03Cr25Ni6Mo3Cu2N 1 000 ~ 1 200, fast-cooling

    Table A.3 Typical heat treatment regulations for ferrite type stainless steel bars or test pieces Code in GB/T 20878

    Unified numerical code New grade Original grade Solution treatment/

    78 780 ~ 830, air cooling or slow-cooling 83 700 ~ 820, air cooling or slow-cooling 85 780 ~ 850, air cooling or slow-cooling 86 680 ~ 820, air cooling or slow-cooling 88 780 ~ 850, air cooling or slow-cooling 94 900 ~ 1 050,

    fast-cooling

    95 900 ~ 1 050,

    fast-cooling

  • GB/T 12202007

    25

    Table A.4 Typical heat treatment regulations for martensite type stainless steel bars or test pieces

    Heat treatment regulations for steel bars

    Heat treatment regulations for test pieces

    Code in

    GB/T 20878

    Unified numerical

    code New grade

    Original grade

    Annealing / Quenching Tempering

    96 800~900 slow-cooling or about 750 fast-cooling

    950~1 000 oil cooling

    700~750 fast-cooling

    97 800~900 slow-cooling or about 750 fast-cooling

    950~1 000 oil cooling

    700~750 fast-cooling

    98 800~900 slow-cooling or about 750 fast-cooling

    950~1 000 oil cooling

    700~750 fast-cooling

    100 800~900 slow-cooling or about 750 fast-cooling

    950~1 000 oil cooling

    700~750 fast-cooling

    101 800~900 slow-cooling or about 750 fast-cooling

    920~980 oil cooling

    600~750 fast-cooling

    102 800~900 slow-cooling or about 750 fast-cooling

    920~980 oil cooling

    600~750 fast-cooling

    103 800~900 slow-cooling or about 750 fast-cooling

    920~980 oil cooling

    600~750 fast-cooling

    104 800~900 slow-cooling or about 750 fast-cooling

    1 050~1 100 oil cooling

    200~300 air cooling

    106 680~700 high-temperature tempering, air cooling

    950~1 050 oil cooling

    275~350 air cooling

    1 600~650 air cooling

    07

    2

    680~800furnace cooling or air cooling

    950~1 050 oil cooling

    or air cooling

    750~800 + 650~700a, air cooling

    108 800~920 slow-cooling 1 010~1 070 oil cooling

    100~180 fast-cooling

    109 800~920 slow-cooling 1 010~1 070 oil cooling

    100~180 fast-cooling

    110 800~920 slow-cooling 1 010~1 070 oil cooling

    100~180 fast-cooling

    111 800~920 slow-cooling 1 010~1 070 oil cooling

    100~180 fast-cooling

    112

    800~920 slow-cooling 1 000~1 050 oil cooling

    200~300 oil, air cooling

    Table A.4 (continued)

    Heat treatment regulations for steel bars

    Heat treatment regulations for test pieces

    Code in

    GB/T 20878

    Unified numerical

    code New grade Original

    grade Annealing / Quenching Tempering

    115 S45710 13Cr13Mo 1Cr13Mo 830~900 slow-cooling or about 750 fast-cooling

    970~1 020 oil cooling

    650~750 fast-cooling

    116 S45830 32Cr13Mo 3Cr13Mo 800~900 slow-cooling or about 750 fast-cooling

    1 025~1 075 oil cooling

    200~300 oil, water or air

    cooling 117 S45990 102Cr17Mo 9Cr18Mo 800~900 slow-cooling 1 000~1 050

    oil cooling 200~300

    air cooling 118 S46990 90Cr18MoV 91Cr18MoV 800~920 slow-cooling 1 050~1 075

    oil cooling 100~200 air

    cooling a When nickel content is of the lower limit as specified in Table 4, it is permissible to carry out single tempering regulations by 620 ~ 720.

  • GB/T 12202007

    26

    Table A.5Typical heat treatment regulations for precipitation-hardening type stainless steel bars or test pieces

    Heat treatment Code in GB/T 20878

    Unified numerical

    code New grade Original grade

    Type group Conditions

    Solution

    treatment

    0 1 020~1 060 , fast-cooling after solution treatment

    480 ageing

    1 470~490 air-cooling after solution treatment

    550 ageing

    2 540~560 air-cooling after solution treatment

    580 ageing

    3 570~590 air-cooling after solution treatment

    136

    S51550

    05Cr15Ni5Cu4Nb

    Precipitation hardening 620 ageing

    4 1 020~1 060 fast-cooling

    Solution

    treatment

    0 1 020~1 060 , fast-cooling after solution treatment

    480 ageing

    1 470~490 air-cooling after solution treatment

    550 ageing

    2 540~560 air-cooling after solution treatment

    580 ageing

    3 570~590 air-cooling after solution treatment

    137

    S51740

    05Cr17Ni4Cu4Nb

    0Cr17Ni4Cu4Nb

    Precipitation hardening 620 ageing

    4 610~630 air-cooling after solution treatment

    Solution

    treatment

    0 1 000~1 100 , fast-cooling

    510 ageing

    1 95510 be kept for 10 minutes after solution treatment, air cooled to room temperature, then cooled to -736 within 24 hours to be held for 8 hours before heating up to 51010 to hold for 1 hours and air cooled

    138

    S51770

    07Cr17Ni7A1

    0Cr17Ni7A1

    Precipitation hardening

    565 ageing

    2 76015 be kept for 90 minutes after solution treatment, cooled to 15 or less within 1 hours to hold for 30 minutes before heating up to 56510 to hold for 90 minutes and air cooled

    Solution

    treatment

    0 1 000~1 100 fast-cooling

    510 ageing

    1 95510 be kept for 10 minutes after solution treatment, air cooled to room temperature, then cooled to -73 6 within 24 hours to be held for 8 hours before heating up to 51010 to hold for 1 hours and air cooled

    139

    S51570

    07Cr15Ni7Mo2A1

    0Cr15Ni7Mo2A1 Precipitation hardening

    565 ageing

    2 76015 be kept for 90 minutes after solution treatment, cooled to 15 or less

  • GB/T 12202007

    27

    within 1 hours to hold for 30 minutes before heating up to 56510 to hold for 90 minutes and air cooled

    Appendix B (Informative appendix)

    Table B.1 Stainless steel properties and applications Code

    in GB/T 20878

    Unified numerical

    code

    New grade Original grade Properties and applications

    Austenite type 1 S35350 12Cr17Mn6Ni5N 1Cr17Mn6Ni5N Ni-free type steel, its property is similar to

    12Cr17Ni7 (1Cr17 Ni7), which can be used in place of 12Cr17Ni7 (1Cr17Ni7). It is nonmagnetic in solution state and slightly magnetic after cold processing. It is mainly used for manufacturing hotel facilities, kitchenware, water pool and traffic means, etc

    3 S35450 12Cr18Mn9Ni5N 1Cr18Mn8Ni5N Ni-free type steel is the most typical and better developed Cr-Mn-Ni-N type steel. It possesses very good anti-oxidation property below 800 while keeping higher strength, which can be used in place of 12Cr18Ni9(1Cr18Ni9). It is mainly used for manufacturing the parts subject to weak media corrosion and load below 800, such as cooking utensils and tableware, etc

    9 S30110 12Cr17Ni7 1Cr17Ni7 Metastable austenite steel is the steel subject to easiest cold deformation strengthening. It can obtain high strength and hardness through cold processing while keeping sufficient plastic strength, it possesses better corrosion resistance under atmospheric conditions. It is mainly used to manufacture the equipment and units that are to withstand higher load under cold processing state while expecting lighter weight and corrosion resistance, such as railway cars, decoration plates, conveyer belt and fasteners, etc

    13 S30210 12Cr18Ni9 1Cr18Ni9 The austenite stainless steel with the longest history possesses excellent plasticity, toughness and cold processing property in solid solution state and better corrosion resistance in oxidable acid, atmosphere, water, steam or other media. Cold processing shall offer high strength, but its elongation is a slightly poorer than 12Cr17Ni7(1Cr17Ni7). It is mainly used to manufacture the structural parts and welded parts with lower requirements on corrosion resistance and strength, such as external decoration materials of buildings; it can be used for nonmagnetic parts and parts for low temperature device. But it intends to have intergranular corrosion in sensitizing state or after welding, so, it is not proper to be used as welded structural material.

    15 S30317 Y12Cr18Ni9 Y1Cr18Ni9 12Cr18Ni9(1Cr18Ni9) improved cutting property steel. It is the best material to make roller, shaft, bolt and nut, etc, by fast cutting (by automatic lathe, etc)

    16 S30327 Y12Cr18Ni9Se Y1Cr18Ni9Se In addition to adjustment made to phosphonium and sulphur contents in 12Cr18Ni9(1Cr18Ni9) steel, selenium has also been added to improve the cutting property of 12Cr18Ni9(1Cr18Ni9) steel. It is applicable to less cutting volume, and also suitable for hot processing or cold processing, such as screw and rivet, etc

  • GB/T 12202007

    28

    17 S30408 06Cr19Ni10 0Cr18Ni9 A steel developed on the basis of 12Cr18Ni9(1Cr18Ni9) steel, its property is similar to 12Cr18Ni9(1Cr18Ni9) steel, but its corrosion resistance is better than 12Cr18Ni9(1Cr18Ni9) steel, it can be used to make welded part of small section dimension, so it is a kind of stainless steel of largest quantity and most extensive range in application. It is suitable for manufacturing deep-punching formed parts, as well as acid delivery pipe, vessel and structural parts, etc, it can also be used to make nonmagnetic/low-temperature equipment and parts

    Table B.1 (continued) Code

    in GB/T 20878

    Unified numerical

    code

    New grade Original grade Properties and applications

    18

    S30403

    022Cr19Ni10

    00Cr19Ni10

    This is a super low carbon austenite stainless steel developed to solve the problem that Cr23C6 seepage make 06Cr19Ni10(0Cr18Ni9) steel have severe intergranular corrosion tendency under certain conditions, its intergranular corrosion resistance in sensitizing state is remarkably better than 06Cr19Ni10(0Cr18Ni9) steel. Except for strength which is a slightly lower, all the other properties are the same as 06Cr19Ni10(0Cr18Ni9) steel, mainly used to make corrosion resistant equipment and parts by way of welding while it is impossible to carry out solution treatment after welding

    22

    S30488

    06Cr18Ni9Cu3

    0Cr18Ni9Cu3

    It is a stainless steel developed on the basis of 06Cr19Ni10(0Cr18Ni9) steel to improve its cold forming property. Addition of copper reduces the hardening tendency in cold processing and the reduction of hardening rate in cold processing offers maximum cold deformation under less forming pressure. It is mainly used to manufacture cold upsetting fastener and parts for cold forming like deep drawing, etc

    23

    S30458 06Cr19Ni10N 0Cr19Ni9N Nitrogen is added to 06Cr19Ni10(0Cr18Ni9) steel, not only to prevent reduction of plasticity, but also to improve steel strength and hardening tendency in processing, improve the pitting corrosion resistance and intergranular corrosion resistance of steel and reduce material thickness. It can be used to make equipment or structural parts requiring certain corrosion resistance, higher strength and lighter weight.

    24

    S30478 06Cr19Ni9NbN 0Cr19Ni10NbN Nitrogen and niobium are added to 06Cr19Ni10(0Cr18Ni9) steel to improve the pitting corrosion resistance and intergranular corrosion resistance of steel, the properties and applications of which are the same as 06Cr19Ni10N(0Cr19Ni9N) steel

    25

    S30453 022Cr19Ni9Ni10N 00Cr18Ni10N It is extra-low carbon steel of 06Cr19Ni10N(0Cr19Ni9N). As the intergranular corrosion resistance of 06Cr19Ni10N (0Cr19Ni9N) steel is remarkably lowered when it is heated under 450 ~ 900 temperature, so 022Cr19Ni10N(00Cr18Ni10N) steel is recommended to welded equipment and parts.

    26

    S30510 10Cr18Ni12 1Cr18Ni12 It is a stainless steel developed on the basis of 12Cr18Ni9(1Cr18Ni9) steel through increasing nickel content in steel. Its processing hardening property is lower than 12Cr18Ni9(1Cr18Ni9) steel. It is suitable for spinning and special purpose drawing, such as used as cold upsetting

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    steel, etc

    32

    S30908

    06Cr23Ni13

    0Cr23Ni13

    High-chrome-nickel austenite stainless steel, its corrosion resistance is better than 06Cr19Ni10(0Cr19Ni9) steel, but it mostly used as heat-resisting steel in actual application

    35 S31008 06Cr25Ni20 0Cr25Ni20 High-chrome-nickel austenite stainless steel with excellent corrosion resistance in oxidable media and very good high-temperature mechanical property, as well, its anti-oxidation property is better than 06Cr23Ni3(0Cr23Ni3) steel, its pitting resistance and stress corrosion resistance are better than 18-8 type stainless steel, it can be used in both corrosion resistant parts and as heat-resisting steel

    38 S31608 06Cr17Ni12Mo2 0Cr17Ni12Mo2 Molybdenum is added to 10Cr18Ni12(1Cr18Ni12) steel so that the steel has excellent properties of reductive media resistance and pitting resistance. In sea water and other media, its corrosion resistance is better than 06Cr19Ni10(0Cr18Ni9) steel. It is mainly used as pitting resistant material

    39 S31603 022Cr17Ni12M02 00Cr17Ni14Mo2 The extra-low carbon steel of 06Cr17Ni12Mo2 (0Cr17Ni12Mo2), with excellent sensitizing state intergranular corrosion resistance. It is suitable for manufacturing the welded parts and equipment of thick section dimension, such as corrosion resistant material for equipment in petrochemical, fertilizer, paper making, printing and dyeing and atomic energy industries

    Table B.1 (continued) Code

    in GB/T 20878

    Unified numerical

    code

    New grade Original grade Properties and applications

    41 S31668 06Cr17Ni12Mo2Ti 0Cr18Ni12Mo3Ti This is a steel species developed to solve the problem that 06Cr17Ni112Mo2(0Cr17Ni12Mo2) steel have intergranular corrosion tendency, it possesses excellent intergranular corrosion resistance and other properties are similar to 06Cr17Ni112Mo2(0Cr17Ni12Mo2) steel. It is suitable for manufacturing welded parts.

    43 S31658 06Cr17Ni12Mo2N 0Cr17Ni12Mo2N Nitrogen is added to 06Cr17Ni12Mo2(0Cr17Ni12Mo2) steel, to improve steel strength without reduction of plasticity and reduce material thickness. It can be used to make parts requiring good corrosion resistance and high strength

    44 S31653 022Cr17Ni12Mo2N 00Cr17Ni13Mo2N Nitrogen is added to 022Cr17Ni12Mo2(00Cr17Ni14Mo2) steel so that it possesses the same properties as 022Cr17Ni12Mo2(00Cr17Ni14Mo2) steel and the applications are the same as 06Cr17Ni12Mo2N(0Cr17Ni12Mo2N) steel, but the intergranular corrosion resistance is much better. It is mainly used in such fields as fertilizer, paper making, medicine making and high pressure equipment, etc

    45 S31688 06Cr18Ni12Mo2Cu2 0Cr18Ni12Mo2Cu2 2% of Cu is added to 06Cr17Ni12Mo2(0Cr17NiMo2) steel to improve its corrosion resistance and pitting corrosion resistance. It is mainly used as sulfuric acid resistant material, which can also be used to make welded structural parts, pipes and vessels, etc

    46 S31683 022Cr18Ni14Mo2Cu2 00Cr18Ni14Mo2Cu2 It is the extra-low carbon steel of

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    06Cr18Ni12Mo2Cu2 (0Cr18Ni12MoCu2) steel. Its intergranular corrosion resistance is better than 06Cr18Ni12Mo2Cu2 (0Cr18Ni12MoCu2) steel. The applications are the same as 06Cr18Ni12Mo2Cu2 (0Cr18Ni12MoCu2) steel

    49 S31708 06Cr19Ni13Mo3 0Cr19Ni13Mo3 The pitting corrosion resistance and creep resistance is better than 06Cr17Ni12Mo2 (0Cr17Ni12Mo) steel. It is used to make paper making equipment, printing and dyeing equipment, petrochemical equipment and organic acid corrosion resistant equipment, etc

    50 S31703 022Cr19Ni13Mo3 00Cr19Ni13Mo3 It is the extra-low carbon steel of 06Cr19Ni13Mo3 (0Cr19Ni13Mo3) steel. Its intergranular corrosion resistance is better than 06Cr19Ni13Mo3 (0Cr19Ni13Mo3) steel. The applications are the same as 06Cr19Ni13Mo3 (0Cr19Ni13Mo3) steel

    52 S31794 03Cr18Ni16Mo5 0Cr18Ni16Mo5 High-molybdenum stainless steel with pitting corrosion resistance better than 022Cr17Ni12Mo2(00Cr17Ni14Mo2) steel and 06Cr17Ni12Mo2Ti (0Cr18Ni12Mo3Ti) steel, and the corrosion resistance in sulfuric acid, formic acid, acetic acid and other media is much better than the common Cr-Ni steel containing 2 % ~ 4% of Mo. It is mainly used in the heat exchanger dealing with chlorine solion, acetic acid equipment, phosphoric acid equipment, bleaching facilities, etc, as well as used in the environment no applicable to less steel with pitting corrosion resistance better than 022Cr17Ni12Mo2 (00Cr17Ni14Mo2) steel and 06Cr17Ni12Mo2Ti (0Cr18Ni12Mo3Ti) steel

    55 S32168 06Cr18Ni11Ti 0Cr18Ni10Ti Titanium is added to titanium stabilized austenite stainless steel to improve intergranular corrosion resistance, which has excellent high-temperature mechanical property. It can be substituted by extra-low carbon austenite stainless steel. It shall not be recommended other than special purposes (high temperature or hydrogen corrosion resistance)

    62 S34778 06Cr18Ni11Nb 0Cr18Ni11Nb Niobium is added to niobium stabilized austenite stainless steel to improve intergranular corrosion resistance, the corrosion resistance in acid, alkali, salt and other media is the same as 06Cr18Ni11Ti (0Cr18Ni10Ti) steel, with good welding performance. It can be used both as corrosion resistance material and heat-resisting steel mainly in thermal power stations and petrochemical fields, etc, to make vessel, pipe, heat exchanger and shafts, etc; it can also be used as welding material

    Table B.1 (continued) Code

    in GB/T 20878

    Unified numerical

    code

    New grade Original grade Properties and applications

    64 S38148 06Cr18Ni13Si4 0Cr18Ni13Si4 Nickel and silicon are added to 06Cr19Ni10 (0Cr18Ni9) steel to improve its stress corrosion resistance and fracture property. It

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    can be used in the environment containing chloride ion, such as vehicle exhaust purifying device, etc

    Austenite-ferrite type 67 S31860 14Cr18Ni11Si4A1Ti 1Cr18Ni11Si4A1Ti Silicon so contained has improved the

    strength and aqua fortis corrosion resistance of the steel, it can be used to make parts and equipment requiring resistance to high temperature and aqua fortis media, such as aqua fortis discharge valve, etc

    68 S21953 022Cr19Ni5Mo3Si2N 00Cr18Ni5Mo3Si2 It is a special purpose stainless steel with chloride stress corrosion resistance formed by adding 0.05% N ~ 0.10% N into Sweden 3RE60 steel. Its corrosion resistance is equivalent to 022Cr17Ni12Mo2 (00Cr17Ni14Mo2) steel. It is applicable to the environment containing chloride ion to make heat exchanger and condenser, etc, for oil refining, fertilizer, paper making, petrochemical and chemical industries, it can also be used in place of 022Cr19Ni10 (00Cr19Ni10) steel and 022Cr17Ni12Mo2 (00Cr17Ni14Mo2) steel for applications in environment subject to stress corrosion damage

    70 S22253 022Cr22Ni5Mo3N Developed on the basis of Sweden SAF2205 steel, it is a dual phase stainless steel of most extensive applications in the world. With resistance to the environment containing hydrogen sulfide, carbon dioxide and chloride, it can be used for cold/hot processing and forming, used as structural material in place of 022Cr19Ni10 (00Cr19Ni10) and 022Cr17Ni12Mo2 (00Cr17Ni14Mo2) austenite stainless steel. It is used to make oil well pipe, chemical storage tank, heat exchanger and condensation cooler, etc, the pressure equipment subject to pitting corrosion and stress corrosion

    71 S22053 022Cr22Ni5Mo3N Derived from 022Cr22Ni5Mo3N, its application range is narrower. The properties and applications are the same as 022Cr22Ni5Mo3N steel

    73 S22553 022Cr25Ni6Mo2N It comes from 0Cr22Ni5Mo3N steel by increasing molybdenum content, decreasing carbon content and adding nitrogen, featuring high strength, chloride stress corrosion resistance and good welding performance, it is a steel of best pitting corrosion resistance. It can be used in place of 0Cr26Ni5Mo2 steel. It is mainly applied in the industrial fields like chemical, fertilizer and petrochemical industries to make heat exchanger and evaporator, etc

    75 S25554 03Cr25Ni6Mo3Cu2N Developed on the basis of British Ferralium alloy 255, it possesses excellent mechanical property and local corrosion resistance, especially, its wear resistance is better than common austenite stainless steel, so, it is an ideal material for sea water environment. It can be used to make screw propeller and shaft for ship, or sealers for submarine, etc, it is also applicable to chemical, petrochemical, natural gas, paper pulp and paper making industries, etc

    Ferrite type 78 S11348 06Cr13A1 0Cr13A1 Low-chrome pure ferrite stainless steel is a

    non-quench hardened steel. Its stainlessness and anti-oxidation is equivalent to low-chrome steel, while its plasticity, toughness and cold forming property is better than other ferrite stainless steels containing higher chrome. It is mainly applied in the places not suitable for 12Cr13(1Cr13) steel or 10Cr17(1Cr17) steel

  • GB/T 12202007

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    because of air quench hardening, such as oil making installation, lining of pressure vessel, blade of steam turbine and clad steel plate, etc

    Table B.1 (continued) Code

    in GB/T 20878

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    code

    New grade Original grade Properties and applications

    83 S11203 022Cr12 00Cr12 It contains less carbon than 022Cr13 (0Cr13), with better bending property at welded position, processing property and high temperature oxidation resistance. It can applied in vehicle exhaust treatment device, boiler combustion chamber, nozzle, etc

    85 S11710 10Cr17 1Cr17 It features high corrosion resistance, mechanical property and thermal conductivity with stainlessness in atmosphere, water vapor or other media, but its stainlessness is not sufficient in the media containing higher chloride ion. It is mainly used in the chemical facilities producing nitric acid and grisoutite, such as absorption tower, heat exchanger, storage tank, etc; sheet plate is mainly applied in internal decorations of building, office equipment, kitchen utensil, car decoration and gas burner, etc. As its brittleness changing temperature is higher than room temperature and it is sensitive to notching, it is not suitable to be used to make the equipment and parts to withstand load below room temperature, and the section dimension for the steel material commonly used shall not exceed 4mm

    86 S11717 Y10Cr17 Y1Cr17 It is a steel for cutting purpose improved from 10Cr17(1Cr17) mainly used to make the parts to be processed with large cutting volume by automatic lathe, such as bolt and nut, etc

    88 S11790 10Cr17Mo 1Cr17Mo Molybdenum is added to 10Cr17(1Cr17) steel to improve the pitting corrosion resistance, crevice corrosion resistance and strength of the steel, its salt solution resistance is better than 10Cr17(1Cr17) steel. It is mainly used as material for vehicle hub, fastener and external decoration of vehicle

    94 S12791 008Cr27Mo 00Cr27Mo It is the earliest steel among high pure ferrite stainless steel, its properties are similar to 008Cr30Mo2(00Cr30Mo2) steel. It is suitable for the applications requiring both corrosion resistance and soft-magnetic

    95 S13091 008Cr30Mo2 00Cr30Mo2 It is a high pure ferrite stainless steel with low brittleness changing temperature and good property of halogen ion stress corrosion damage resistance, its corrosion resistance is equivalent to pure nickel, possessing excellent toughness, processing/forming properties and welding performance. It is mainly applied in complete set of equipment for chemical industry (acetic acid, lactic acid or other organic acids and superalkali concentration engineering), food industry, oil refining industry, electric power industry, water treatment industry and pollution control, etc, to make heat exchanger, pressure vessel, tank and other equipment

    Martensite type 96 S40310 12Cr12 1Cr12 It is an excellent heat-resisting stainless steel for steam

    turbine blades and high-stress parts 97 S41008 06Cr13 0Cr13 Applicable to parts requiring higher toughness and subject to

    impact load, such as steam turbine blades, structural frame, lining, bolt and screw cap ,etc

    98 S41010 12Cr13 1Cr13 It is a semi-martensite type stainless steel with higher strength and toughness through quench tempering treatment, it possesses excellent corrosion resistance and machining property. It is mainly applied to the parts requiring higher toughness, stainlessness and subject to impact load, such as

  • GB/T 12202007

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    cutting tool, blade, fastener, valve for water press and pyrolysis ant-sulphur corrosion equipment, etc; it can also be used to make the equipment and parts requiring weak corrosive media resistance under normal temperature condition

    100 S41617 Y12Cr13 Y1Cr13 It is a steel with best cutting property among stainless steel, used for automatic lathe

    Table B.1 (continued) Code

    in GB/T 20878

    Unified numerical

    code

    New grade Original grade Properties and applications

    101 S42020 20Cr13 2Cr13 Martensite type stainless steel, main properties are similar to 12Cr13(1Cr13). As the carbon content is higher, its strength and hardness is higher than 12Cr13(1Cr13) while its toughness and corrosion resistance is lower. Mainly used to make parts subject to high stress load, such as steam turbine blade, hot oil pump and its shaft, shaft sleeve and blade, valve element for water press, etc, it can also be applied in paper making industry, medical device industry and everyday consumables field to make cutting tool and tableware ,etc

    102 S42030 30Cr13 3Cr13 It is Martensite type stainless steel, its strength, hardness and hardenability is better than 12Cr13(1Cr13) and 20Cr13(2Cr13) steels, with certain corrosion resistance in diluted nitric acid and weak organic cid under room temperature, but it is no better than 12Cr13(1Cr13) and 20Cr13(2Cr13) steels. It is mainly used for strength parts, as well as wearing parts subject to high stress load under certain corrosive media conditions, such as cutting tools and spring to operate under 300 degree or less, and the shaft, bolt, valve and bearing to operate under 400 degree temperature, etc

    103 S42037 Y30Cr13 Y3Cr13 It is a steel to improve the cutting property of 30Cr13(3Cr13) steel. The applications are similar to 30Cr13(3Cr13) steel, requiring better cutting property

    104 S42040 40Cr13 4Cr13 The property and applications are similar to 30Cr13(3Cr13) steel, but its toughness and corrosion resistance is slightly lower. Mainly used to make surgical apparatus, bearing, valve and spring, etc. 40Cr13 (4Cr13) steel possesses poor welding performance, not good for manufacturing welded parts

    106 S43110 14Cr17Ni2 4Cr17Ni2 It shall obtain higher mechanical property from heat treatment, its corrosion resistance is better than 12Cr13(1Cr13) and 10Cr17(1Cr17) steels. It is usually used to make shafts, piston rod, pump, valve, as well as spring and fastener, etc, requiring both high hardenability of mechanical property and resistance to nitric acid and organic acid corrosion

    107 S43120 17Cr16Ni2 Its processing property is obviously better than 14Cr17Ni2 (1Cr17Ni2) steel, suitable for making corrosion resistant parts requiring higher strength, toughness and plasticity and load bearing parts working in damp media

    108 S44070 68Cr17 7Cr17 High-chrome Martensite type stainless steel, its hardenability is higher than 20Cr13(2Cr13) steel. In quench hardened state, it possesses high strength and hardness while having stainlessness and corrosion resistance. It is usually used to make cutting tool, measuring tool, shafts, levers, valve, hooks and other corrosion resistant parts requiring stainlessness and resistance to the corrosion of diluted oxidable acid, organic acid and salts

    109 S44080 85Cr17 8Cr17 It is a hardenable stainless steel. Its property and applications are similar to 68Cr17 (7Cr17) steel, but when it is hardened, the hardness is larger than 68Cr17(7Cr17) steel while toughness is better than 108Cr17(11Cr17) steel. It is used to make cutting tool and valve seat, etc

    110 S44096 108Cr17 11Cr17 Its hardness is the highest among hardenable stainless steels

  • GB/T 12202007

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    and stainless steels. Its property and applications are similar to 68Cr17 (7Cr17) steel. It is used to make jet nozzle and bearing, etc

    111 S44097 Y108Cr17 Y11Cr17 It is a steel species improve from 108Cr17 (11Cr17) steel. It is designed for automatic lathe

    Table B.1 (continued) Code

    in GB/T 20878

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    code

    New grade Original grade Properties and applications

    112

    S44090 95Cr18 9Cr18 High-carbon Martensite type stainless steel. Corrosion resistance is better than Cr17 type Martensite type stainless steel, while other properties are similar to Cr17 type Martensite type stainless steel. It is mainly used to make corrosion resistant and wearing resistant high-strength parts, such as shaft, pump, valve element, levers, spring and fastener, etc. Uneven carbohydrate is easy to form in this steel to affect steel quality and property, which should be noted in production.

    115 S45710 13Cr13Mo 1Cr13Mo It is high strength steel with better corrosion resistance than 12Cr13(1Cr13) steel. It is used to make steam turbine blades and high temperature parts, etc

    116 SS45830 32Cr13Mo 3Cr13Mo Molybdenum is added to 30Cr13(3Cr13) steel to improve steel strength and hardness, which has also strengthened secondary hardening effect, and it corrosion resistance is better than 30Cr13(3Cr13) steel. Its main applications are similar to 30Cr13(3Cr13) steel

    117 S45990 102Cr17Mo 9Cr18Mo 118 S46990 90Cr18MoV 9Cr18MoV

    The property and applications are similar to 95Cr18(9Cr18) steel. Because molybdenum and vanadium are added to this steel, its high temperature strength and anti-tempering capacity are better than 95Cr18(9Cr18) steel. The main applications are the same as 30Cr13(3Cr13) steel. It is mainly used to make the parts to withstand friction and work in corrosive media, such as measuring tool and cutting tool, etc

    Precipitation-hardening type 136 S51550 05Cr15Ni5Cu4Nb It is martensite precipitation-hardening type

    stainless steel developed from 05Cr17Ni4Cu4Nb (1Cr17Ni2) steel, in addition to high strength, it possesses also high transverse toughness and sound forgeability, its corrosion resistance is equivalent to 05Cr17Ni4Cu4Nb (1Cr17Ni2) steel, it is mainly applied to the service environment requiring not only high strength and good toughness, but also excellent corrosion resistance, such as high strength forged parts, valve elements of high pressure system and parts of air plane

    137 S51740 05Cr17Ni4Cu4Nb 0Cr17Ni4Cu4Nb It is martensite precipitation-hardening type stainless steel added with copper and niobium, its strength can be adjusted through changing heat treatment technique, the corrosion resistance is better than Cr13 type, 95Cr18(9Cr18) and 14Cr17Ni2 (1Cr17Ni2) steels, the resistance to corrosion, fatigue and water drop erosion is better than 12% martensite type stainless steel, welding

  • GB/T 12202007

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    procedure is simple and easy to be processed, but it is hard to conduct deep cold forming. It is mainly used to make high strength parts requiring both of stainlessness and resistance to corrosion of weak acid, alkalis and salt. Such as the final level moving blade of steam turbine and the structural parts working in corrosive environment with operating temperature to be less than 300

    138 S51770 07Cr17Ni7A1 0Cr17Ni7A1 It is semi-martensite precipitation-hardening type stainless steel added with aluminium, the compositions is nearly the same as 18-8 type austenite stainless steel with excellent melting and processing properties. It can be used to make the structural parts, vessel, pipe, spring, washer and measuring device parts to work below 350 for a prolonged period of time. The technique for heat treatment of this steel is complicated, so there is tendency to be substituted by martensite ageing worldwide, but there are still extensive application fields

    139 S51570 07Cr15Ni7Mo2A1 0Cr15Ni7Mo2A1 It is a semi-martensite precipitation-hardening type stainless steel using 2% Mo to substitute 2% Cr in 07Cr17NiAl (0Cr17NiAl) steel to improve its resistance to the corrosion of reductive media and its comprehensive performance is better than 07Cr17NiAl (0Cr17NiAl) steel. It is used to make the high strength vessel, parts and structural parts with certain corrosion resistant requirements in astronautical navigation, petrochemical and energy fields ,etc

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    4.GBT1220-2007--Stainless Steel Bars-en-