Att välja material till bärande konstruktionerHasse Groth & Thérèse SternelandAvesta Research CenterOutokumpu
Älvsjö 2017-10-25
10/30/2017 2
Innehåll
1. Vad är rostfritt stål och olika typer?
2. Duplexa rostfria stål
3. Att välja material
4. Erfarenheter
10/30/2017 3
Vad är rostfritt stål?
Fe + >10.5% Cr“1 mm“
Vykort• Järn med tillsats av minst 10.5% krom
• Naturligt bildad passivfilm
• 20-30 Å = 0.000 002 - 0.000 003 mm
• Självläkande
passivfilm
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• Kombinationen av legeringselement ger en mikrostruktur som ger vissa typiska egenskaper. Ståltillverkare gillar denna indelning! (Tillverkning Världen/Sverige)
Olika typer av rostfria stål
Ferritiska stål Krom.Magnetiskt. Vanligt förekommande. (19/1%)
Martensitiska stål Krom + ganska mycket kol.Ej i Eurocode Hög hållfasthet, härdbara. Knivstål.
Duplexa stål Mycket Krom – lite Ni, Mo, N. 50% ferrit-50% austenit Hög hållfasthet. Växer snabbast. (1/29%)
Austenitiska stål Krom + Nickel (Mo, N). Formbarhet, svetsbarhet. Vanligast. (80/70%)
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Olika typer av rostfria stål-olika egenskaper
Ferritiska stålLämpliga i mildare miljöer
Martensitiska stålLämpliga i milda miljöer därhårdhet krävs
Austenitiska stålFrån milda till aggressiva miljöer
Duplexa stålFrån milda till aggressiva miljöer, hög hållfasthet
10/30/2017 7
Innehåll
1. Vad är rostfritt stål och olika typer?
2. Duplexa rostfria stål
3. Att välja material
4. Erfarenheter
8
What is Duplex Stainless Steel?• Duplex stainless steel has a ferritic-austenitic
microstructure
• The phase balance is approximately 50% ferrite and 50% austenite
• Duplex stainless steel combines most of the beneficial properties of ferritic and austenitic steels
• The duplex microstructure contributes to high strength and high resistance to stress corrosion cracking
9
Duplex- a long history at Outokumpu
Seawater
Dec 23, 1930
453S (~ASTM 329)Brobeck cooler in grade 453 S
10
History
Second generation Duplex
• Process development (AOD)made it possible to reducethe carbon content and toalloy with nitrogen.
• The nitrogen improved the formation of austenite after welding
• 2205 was invented in the 1970’s
11
History
Third generation Duplex
• Super duplex
Grades with Cr content 25% or more
High levels of Cr, Mo, N and sometimes W give high resistance to localized corrosion
• Lean duplex
Grades with low Ni content often replaced with Mo and N
13
Product performance comparison
Yield strength vs. corrosion resistance
PRE = % Cr + 3.3 x % Mo + 16 x % N. Yield strength (Rp0.2) uses EN 10088-2 minimum values for cold rolled strip
Forta range Duplex
Positioning of Duplex gradesAn excellent combination of high strength and corrosion resistance
600
550
500
450
400
350
300
250
200
150
Dup
lex
Aust
entic
Core 304L/4307
Supra 316L/4404
Supra 316L/4436
Ultra 317LUltra 4439
Ultra 904L Ultra 254 SMO
Ultra 4565
Forta LDX 2101
Forta DX 2304
Forta DX 2205
Forta SDX 2507Forta LDX 2404
Corrosion Resistance, CPT typical
Stre
ngth
, Rp0
.2 [M
Pa]
Hot coil
Ultra 654 SMO
14
Forta EDX 2304
Duplex products• HRP(P), Quarto Plate: t = 2-100* mm
• CPP(H), coil and plate: t = 4-10* mm
• CR (C), coil, strip & sheet: t = 0.1-6* mm
• Billet, wire rod, bar and rebar
• Welded tube and pipe
• Fittings
• Structural profiles - Duprof™: ≤ 6 m as standard, max 13 m
*Max/min. thickness – grade and width dependent.
15
High Mechanical StrengthSolid Solution hardening
17
Atoms of another size than the pure metal is causing a disorder in the material which leads to hardening.
Nitrogen is an example of a small atom that solutes between the iron atoms in stainless steels.
18
General characteristics of Forta range Duplex products
• High mechanical strength (Rp min > 400 MPa)
• High resistance to localized corrosion (PRE 26 to 43) and stress corrosion cracking
• High wear resistance• Low thermal expansion• High energy absorption• Good fabricability
Cost effective and sustainable solutions
Courtesy of Outotec.
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• Storage tanks
• Pressure vessels
• Bridge components
• Flexible pipes (Oil & Gas)
• Blast walls (Offshore)
• Thickeners (Mineral processing)
• Water gates
Applications: Forta range duplex
Courtesy of IKM dsc Engineering
10/30/2017 20
Innehåll
1. Vad är rostfritt stål och olika typer?
2. Duplexa rostfria stål
3. Att välja material
4. Erfarenheter
10/30/2017 21
Korrosionsmotstånd, några vanliga stålOutokumpu EN Struktur Cr Ni Mo N PRE*
Moda 4016 1.4016 ferrit 16.2 16
Core 4509 1.4509 ferrit 18.0 18
Core 4307 1.4307 austenit 18.1 8.1 18
Core 4404 1.4404 austenit 17.2 10.1 2.1 24
Ultra 254 SMO 1.4547 austenit 20.0 18.0 6.1 0.20 43
Forta LDX 2101 1.4162 duplex 21.5 1.5 0.3 0.22 26
Forta DX 2205 1.4462 duplex 22.0 5.7 3.1 0.17 35
Forta SDX 2507 1.4410 duplex 25.0 7.0 4.0 0.27 43
*PRE, Pitting Resistance Equivalent,
PRE = %Cr + 3.3 × %Mo + 16 × %N
PRE är ett grovt verktyg för att rangordna olika rostfria ståls motstånd mot punktfrätning
10/30/2017 22
PunktfrätningsegenskaperKritisk punktfrätningstemperatur, ASTM G150
100
90
80
70
60
50
40
30
20
10
0
CPT,
°C
1.40
16
1.45
21
1.44
32
1.44
04
Ultra
904
L (1
.453
9)
Ultra
254
SM
O (1
.454
7)
Fort
aLD
X 21
01 (1
.416
2)
Fort
aD
X 23
04 (1
.436
2)
Fort
aD
X220
5 (1
.446
2)
Fort
aSD
X 25
07 (1
.441
0)
1.43
07
10/30/2017 25
Korrosivitetsklasser (ISO 9223) och erforderliga rostfria stål
ISO Corrosivity Typical environments Grades
C1 Very low Dry or cold zone: Central Arctic/ Antarctica and certain deserts. 1.4016, 1.4307, 1.4162
C2 Low Temperate zone: rural areas and small towns. Dry or cold zone: deserts and subarctic areas.
1.4016, 1.4307, 1.4162
C3 Medium Temperate zone: urban areas and costal areas with low deposition of chlorides. Subtropical and tropical zone: areas with low pollution.
1.4301, 1.4404, 1.4162, 1.4362
C4 High Temperate zone: polluted urban areas, industrial areas, costal areas without spray and exposure to de-icing salts. Subtropical and tropical zone: areas with medium pollution.
1.4404, 1.4162, 1.4362, 1.4462, 1.4539, 1.4410, 1.4547
C5 Very high Temperate and subtropical zone: industrial areas, coastal areas and sheltered positions on coast line.
1.4462, 1.4539, 1.4410, 1.4547, 1.4565, 1.4652
CX Extreme Subtropical and tropical zone: extreme industrial areas, coastal and offshore areas.
1.4410, 1.4547, 1.4565, 1.4652
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Eurocode 3:EN 1993-1-4/A1:2015
Corrosion Resistance FactorCRF = F1 + F2 + F3
F1 = Risk of exposure to chlorides from salt water or deicing salts; F2 = Risk of exposure to sulfur dioxide; F3 = Cleaning regime or exposure to washing by rain.
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Effekten av ytfinhetForta LDX 2101®, 2 års exponering vid Bohus Malmön, Svenska västkusten
Ra 0.2 µm Ra 0.5 µm Ra 0.8 µm
Finare ytor – mindre risk för initiering av korrosion
Missfärgning på ytan - Estetiskt, påverkar ej hållfasthet
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Case: Gateway Arch, USA
• Stainless steel load bearing structure made in 1965.
• Arch design included load bearing, welded, stainless steel plate in grade 316 (1.4401).
• Inspection after 50 years – Dirty, but in good shape!
• At that time - Minimal structural research, no duplex
• It was found that structural research was needed!
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Hur mycket rostar 1.4404 på ett tak i Stockholm?
1) Hur lång tid tar det innan 1 gram försvinner på en 1 m2 yta takplåt 1.4404?
(Tips: Materialet är beständigt i denna miljö. Det regnar på plåten regelbundet.)
2) En takplåt är normalt 0.5 mm tjock och väger 4 kg/m2. Hur lång tid tar det innan 0.1 mm försvinner?
Källa: Korrosionsinstitutet/KIMAB
10/30/2017 34
Innehåll
1. Vad är rostfritt stål och olika typer?
2. Duplexa rostfria stål
3. Att välja material
4. Erfarenheter
Vanliga duplexstål i broar
• Forta DX 2205, 1.4462
• Forta DX 2304, 1.4362
• Forta LDX 2101, 1.4162
• Forta LDX 2404, 1.4662 – Nytt
Inspection of Duplex bridges• To collect field experience of stainless steel bridges.
• Observe and record the condition and performance of various stainlesssteel components at site.
• Document and inform the designers of future stainless steel structureby providing a reference point for past sucessful applications.
• To provide data for future design standard revisions, EN 1993-1-4, Annex A relating to material selection.
Acknowledgement Sukanya Hägg Mameng och Jan Björk
Sölvesborg, 2013Grade 1.4162
Flen Bridge, 2009Grade 1.4162
Sicklauddsbron, 2002Grade 1.4462
Nynäshamn, 2011Grade 1.4162
Celtic Gateway, 2006Grade 1.4362
Saint Fruitos, 2009Grade 1.4162
Zumaia, 2008Grade 1.4462
Anorga, 2011Grade 1.4162
Puerto Arrupe 2003Grade 1.4362
Cala Galdana, 2005Grade 1.4462
Millenium, 2000Grade 1.4462
Spain
UK
Inspekterade broar
CRC III
CRC III CRC IV
CRC III
CRC II, III
CRC II, III
CRC II, IIICRC II, III
CRC II, III
CRC II, III
CRC IV, V
CRC = Corrosion Resistance Class (EN 1993-1-4 Annex A )
Klassningar
• Risk of exposure to chlorides from sea salt water• M=Distance from the sea
CRC II, III
Low *(M > 10 km)
Medium *(1 km < M ≤10 km)
High*(0,25 km < M ≤1 km)
Very high*(M ≤0,25 km)
CRC III CRC IV/V
Orrhammarvägen Bridge Duplex grade 1.4162
6 years
Añorga BridgeDuplex grade 1.4162
4 years
Millenium Bridge Duplex grade 1.4462
15 years
Puerto Arrupe BridgeDuplex grade 1.4362
12 years
Zumaia BridgeDuplex grade 1.4462
7 years
Cala GaldanaDuplex grade 1.4462
10 years
Note: No information about cleaning and mainternance done was available.
CRC = Corrosion Resistance Class (EN 1993-1-4 Annex A )
General information:- Year constructed: 2002 Location: Sweden- ISO 9223 Class: C3- Above channel, 255 ppm Cl- measured- Rain washed
Sicklauddsbron Pedestrian Bridge
10/30/2017This information is given in good faith and Outokumpu assume no liability for it 39
Materials:Forta DX 2205, beams, flange, handrail- Generally in good condition- Ra 4.0 µm316L, end cover tube of bridge cables- Good condition, some staining due to contamination304, brackets and stanchion- Overall in good condition but isolated pits can be observed
Orrhammarvägen Bridge Location: Flen, Sweden Structure type: Road bridgeCorrosion resistance class: CRC II, III Year of completion: 2009 (6 years)Distance from the salt water: ~60 km Local environmental notes: 8 ppm Cl- measured
Longitudinal beam web Longitudinal beam flangeGrade 1.4162
Longitudinal beam weldER 23 7 NL
Bridge bearing plateGrade 1.4162
Inspection date: 10/06/2015
Orrhammarvägen Bridge
Bottom of beam: Orange stain and contamination Small bolts: Poor condition. Galvanizing was visible on the bolt heads but not the shanks or nuts.
Welded areas: Some accumulation of dirt/dustBridge beams (Ra~5.0 µm): General appearance is in good condition
Inspection date: 10/06/2015
Sheltered condition Sheltered conditionSheltered condition
1.4162
Spectrum C O Mg Si K Ca Mn Fe TotalSpectrum 1 6.97 42.7 1.72 2.54 0.78 0.72 44.5 100Spectrum 2 8.31 40.6 2.42 2.57 0.93 0.67 0.68 43.9 100Max. 8.31 42.7 2.42 2.57 0.93 0.67 0.72 44.5Min. 6.97 40.6 1.72 2.54 0.78 0.67 0.68 43.9
Bottom of beam: Orange stain and contamination from mild steel after the surface finishing was applied (No chloride ion was found).
Orrhammarvägen Bridge
SEM/EDS-result
Inspection date: 10/06/2015
1.4162
Añorga Bridge
Handrail poleHandrail cable fittingHandrail tie plateGrade 1.4401
Bridge beam (Ra~8 µm)Grade 1.4162
Arch transition structure top surface (Ra~6 µm)Grade 1.4301
Arch transition structure side surfaceGrade 1.4162
Main arch Grade 1.4162
Arch weldER 23 7 NL
Location: San Sebastian, Spain Structure type: Railway bridgeCorrosion resistance class:Distance from the salt water:
CRC II, III~ 3 km
Year of completion: 2011 (4 years)
Inspection date: 20/10/2015
Añorga Bridge
Handrail pole, cable fitting and tie plateArch weld
Main arch
Inspection date: 20/10/2015
1.41621.4401
1.4401
Puerto Arrupe BridgeLocation: Bilbao, Spain Structure type: Footbridge / CyclewayCorrosion resistance class: CRC II, III Year of completion: 2003 (12 years)Distance from the salt water: ~10 km Local environmental notes: 2,400 ppm Cl- measured
Tubular handrailGrade 1.4401
Bridge box side surfaceBridge box finGrade 1.4362
Bridge box side surface at stairGrade 1.4362
Bridge box to fin weldER 22 9 3NL
FinWeld
Bridge box side surface at stair
Handrail
Fin
Fin
Wood
Inspection date: 20/10/2015
Puerto Arrupe Bridge
Bridge box side surface (Ra ~4 µm), welds and fin: Good condition
Bridge box surface in sheltered area: Some accumulation of dirt and staining. Discoloration is likely due to no washing, fabrication or transportation.
Bridge box side and fins: Orange stain → Fabrication (grinding, spatter from welding). No chloride ion was observed at this point (SEM/EDS)
Welds: Some scratch, dark spot from weld oxide and accumulation of dirt.
Inspection date: 20/10/2015
Open condition Sheltered condition Sheltered condition
1.4362
1.4362
Puerto Arrupe Bridge
Internal side surface and bridge box side surface at stair: Color painting to covering all scratches, vandalism, accidental contact with bicycles, dog urine, etc.,
Bridge box fins under surface at stair: Orange staining and discoloration
Bridge box fins (Ra 4 µm): Easy to trap water and some green organic matter was growing in this area.
Inspection date: 20/10/2015
Sheltered condition
1.4362
1.4362
Millennium Bridge
Bridge arch (Ra ~0.3 µm)1.4462
Cable fitting and boltSuspension cable1.4401
Balustrade infill framing1.4301
Handrail1.4401
Balustrade stanchionPainted carbon steel
Balustrade handrail1.4401
Bridge deck kurb1.4401
Location: York, UK Structure type: Pedestrian bridgeCorrosion resistance class: CRC II, III Year constructed: 2000 (15 years)Distance from the salt water: ~60 km Local environmental notes: 20 ppm Cl- measured
Inspection date: 17/08/2015
Millennium Bridge
Junction between arch and deck:Stain was noted.
Arch (Ra ~0.3 µm): Discoloration is more related to birds (some bird droppings) that evidently perch on the arch. No corrosion was observed.
Mesh frame (Ra~ 0.3 µm) and Infill mesh: Good condition
Handrail design: Easy to trap water and some green organic matter was growing in this area.
Cable: Good condition with some staining and debris were observed.
Inspection date: 17/08/2015
Open condition Sheltered condition1.4462
1.4462
1.4462
1.43011.4401 1.4401
1.4401
Millennium Bridge
Stanchions - vertical direction: Some staining
Handrail (circular section): Good condition
Fin at the northwestern side: Orange staining consistent with contamination from mild steel. No evidence of structurally concerning corrosion.
Horizontal direction (Ra~2.5 µm): Some staining
Inspection date: 17/08/2015
1.44011.4401 1.4401
1.4401
Painted carbon steel
Zumaia BridgeLocation: Zumaia, Spain Structure type: FootbridgeCorrosion resistance class: CRC III Year of completion: 2008 (7 years)Distance from the salt water: ~1 km Local environmental notes: 15,200 ppm Cl- measured
Inspection date: 20/10/2015
Zumaia Bridge
Bridge beamGrade 1.4462
Balustrade top surfaceGrade 1.4462WeldER 22 9 3NL
Bridge beam (Deck facing surface) Grade 1.4462
Balustrade infill bracketGrade 1.4462 Bolt headGrade 1.4401
Checker plate flooringGrade 1.4301
Balustrade end plateGrade 1.4462WeldER 22 9 3NL
WeldWeld
Stiffening angle under handrailGrade 1.4462
Handrail extension plateGrade 1.4462
Fiber glass
(Ra ~ 4 µm)
Inspection date: 20/10/2015
HandrailWood
Zumaia footbridge
Bridge beam
Balustrade top surface(Ra~5-6 µm)
• General appearance to be in good condition. • No chloride ion (SEM) was found on the surface.
Bridge beamBridge beam (Deck facing surface, Ra~4-5 µm)
Weld
Weld Weld
• Staining and discoloration was observed on the surface. • No corrosion attack were observed
Inspection date: 20/10/2015
1.4462
1.44621.4462
Zumaia footbridge
Orange stain on the dome nuts and under crevice area .
Balustrade top surface and end plate: Orange stain→ Fabrication (grinding) of carbon steel fence (handrail) beside the bridge
Weld oxide and heat tints
Inspection date: 20/10/2015
1.4462
1.4462
1.4401
Cala Galdana BridgeLocation: Menorca, Spain Structure type: Road and foot bridgeCorrosion resistance class: CRC IV/V Year of completion: 2005 (10 years)Distance from the salt water: < 250 m Local environmental notes: 17,300 ppm Cl- measured
Inspection date: 22/10/2015
Cala Galdana Bridge
Balustrade staunchion (Bracket plate and plate)Balustrade infill tube and hand railGrade 1.4462
Bridge deck main beamBridge deck outrigger beamGrade 1.4462
Bridge archGrade 1.4462
Bridge arch infill plateGrade 1.4462
Vehicle barrier tube Bracket base platePlateGrade 1.4401
Main bridge arch weldER 22 9 3NL
Vehicle barrier to arch transitionER 19 12 3 L
Bolt and nutGalvanized steel
Vehicle barrier bracket weldER 22 9 3NL
Inspection date: 22/10/2015
Cala Galdana Bridge
Main bridge arch, infill plate and weld: General appearance to be in good condition
Infill plate(Ra ~4-5 µm) Weld Weld
Weld
Balustrades (Ra 3-6 µm): Grey staining and discoloration was observed on the surface.
Inspection date: 22/10/2015
1.4462
1.4462
1.4462
1.4462
Cala Galdana Bridge
Fabrication: Some weld spatter was observed but did not cause any corrosion.
Fabrication: Orange staining at creviced associated with weld joint between two tubes
Bridge deck: Good condition. Staining from water run off
Bolt and nut: Red rust and corrosion
Inspection date: 22/10/2015
Sheltered condition Sheltered condition Sheltered condition1.4462
1.4462 1.4462
1.4401
Cala Galdana Bridge
1.4401
1.4462 1.4401
1.4462
1.4401
ER 22 9 3NL
ER 19 12 3 L
Galvanized steel
Inspection date: 22/10/2015
General information:- Year constructed: 2013 Location: Sweden- ISO 9223 Class: C2- Saline Bay, 3997 ppm Cl- in the water- Corrosion resistance class II or III in general depending on frequency of rain washing
Sölvesborg Pedestrian and Cycle Bridge
10/30/2017This information is given in good faith and Outokumpu assume no liability for it 60
Materials:Forta LDX 2101 on arch- Generally in good condition- Ra 3.0 µm316L hand rails, cable fittings- Some orange staining from contamination- Ra 3.0 µm
Resultat
• Fel: Kolstålsavskrap, kapskivesprut, svetssprut, dåligt betade svetsar, kolstålsskruvar, felstålsort
• Inget som påverkar funktionen.
• Materialvalen som gjorts i dessa fall kan bedömas som rätt och överenstämmer i principmed Eurocodereglerna.
• Det allmänna intrycket från inspektionerna är att broarna är i generellt gott skick.
• De flesta anmärkningarna kommer från kontaminering, fabrikation, transport eller“dagligt bruk”.