Study on test procedure development to evaluate pipe ...mycommittees.api.org/standards/api1104/Meeting Materials/2013...test procedure development to evaluate pipe ... API 5L X65QO

© 2013 NIPPON STEEL & SUMITOMO METAL CORPORATION All Rights Reserved.

API 1104 Committee Meeting, Jan. 2013

1

Study on test procedure development to evaluate pipe properties

at HAZ in girth welded portion

Masahiko Hamada, Hiroyuki Nagayama Jun Nakamura, Hidenori Shitamoto

Tetsuya Fukuba



2

Outlines /Field girth welding simulation project in NSSMC Main part: Test procedure development to evaluate pipe properties in HAZ /Introduction /Outlines of developing test procedure /Review of trial test results Macrographic examination, CTOD, CVN, Hardness /Summary



3

Field girth welding simulation project in Nippon Steel & Sumitomo Metal Corporation

<Objective> •Better understanding on field girth welding •Better understanding on properties of HAZ in girth welds •Feedback on material design •Better communication with customers



4

Field girth welding simulation project in Nippon Steel & Sumitomo Metal Corporation

Pipe mills S’less: Wakayama UOE: Kashima & Kimitsu HFW: Hikari & Nagoya

Welding joint marketing & development dep. (2007~)

Pipe & Tube business unit

R&D Center Material, Corrosion Welding, Mechanics

NIPPON STEEL & SUMIKIN Pipeline & Engineering (Domestic pipeline contractor)

Project organization



5

Narrow gap PGMAW in 1G position

Pipe size: 323.9mm OD x 53mm WT, Bevel angle: 5 deg. Pass numbers: 19 pass, Root pass: STT without Cu-backing



6

Narrow gap PGMAW in 5G position

Pipe size: 273mm OD x 14mm WT, Bevel angle: 5 deg. Root pass: STT without Cu-backing



7

SAW in 1G position

Installation in 2011



8

Introduction

•Nippon Steel & Sumitomo Metal Co. (NSSMC) is conducting test procedure development to evaluate pipe properties (especially CTOD properties) at HAZ in girth welded portion. •API-1104 does not cover the test procedure to evaluate base metal properties at HAZ. •API-RP-2Z covers this area but the recommended welding conditions is deferent from the field girth welding of pipe line constructions.



9

Outline of the test procedure (for welding)

<Bevel design> Single-bevel (half-K bevel) (Figure shows an example. ) <Welding process> Mechanized GMAW/PGMAW Mechanized SAW <Welding position> ASME 1G (Pipe rotating)

2.0-10.0

40

+/ - 10 o

1.0 +/ - 1.0

20 +/ - 5

5.0-15.0

(mm)

Backing ring

o

Items in this page is same as API-RP-2Z



10

Outline of the test procedure (for welding)

API-RP-2Z NSSMC procedure

Weld heat input (kJ/mm)

0.8 3.0 4.5 0.5 1.6

Preheat/ Inter pass temp.

(deg. C) Max.100 100~250 min. 250 Max.50 125~150

Welding conditions

•NSSMC considered that the main line welding could be covered our proposal for welding conditions. •An extra larger heat input condition should be considered for the double joint process.



11

Outline of the test procedure (for CTOD test)

API-RP-2Z NSSMC procedure

HAZ straightness

Precrack intersect the etched HAZ for 75% of central 2/3 of the specimen thickness.

Measured the fusion line straightness in 60% of wall thickness. Target value is less than 1.0 mm

Precrack position for coarse grain

specimen

More than 15% of precrack in CGHAZ within *0.3 or 0.5 mm of fusion line. The 15% must be within central 2/3 of the specimen. *0.3 mm for 0.8kJ/mm 0.5 mm for 3.0 &4.5kJ/mm

1. Average distance from precrack to fusion line should be 0.5 mm or less.

2. HAZ ratio on precrack should be 80 % or more.

3. Unaltered CGHAZ ratio at fusion line should be 25 % or more

Metallographic examination



12


60% of wall

thickness

1.0mm or less1.0mm or less

HAZ straightness



13


Unaltered CGHAZ ratio

Etched HAZ

CGHAZ next to un-

refined columnar weld

metal

(Unaltered CGHAZ)

Criterion

Total length of Unaltered

CGHAZ >= 25% in 60% of

wall thickness



14

<Test pipe> Grade: API 5L X65QO PSL2 OD x WT: 8.625” x 1.317” (219.1mm x 33.45mm) <Welding conditions> 1. Low heat input Process: PGMAW, Position: 1G Aimed heat input: 0.5kJ/mm Preheat/ Interpass temp.: max. 50 deg.C 2. High heat input Process: SAW, Position: 1G Aimed heat input: 1.6 kJ/mm Preheat/ Interpass temp.: 125~150 deg.C

Trial test results



15

Macrographic examination for 0.5kJ/mm GMAW joint

In 60 % of wall thickness HAZ straightness: 0.76 mm, Unaltered CGHAZ: 64.9 %

Trial test results



16

Macrographic examination for 1.6 kJ/mm SAW joint

In 60 % of wall thickness HAZ straightness: 0.98 mm, Unaltered CGHAZ: 52.5 %

Trial test results



17

HAZ straightness & unaltered CGHAZ ratio

WPS Joint ID

Specimen ID

HAZ straightness (mm)

Unaltered CGHAZ (%)

PGMAW 0.5 kJ/mm

M-2 MW-1 0.76 64.9%

MW-2 0.88 66.9%

M-3 MW-3 0.68 58.9%

MW-4 0.73 62.8%

SAW 1.6 kJ/mm

S-2 SW-1 0.98 52.5%

SW-2 0.85 57.3%

S-3 SW-3 0.95 67.1%

SW-4 0.56 63.8%

In 60 % of wall thickness; HAZ straightness was controlled less than 1.0 mm Unaltered CGHAZ ratio was more than 50 %

Trial test results



18

Average distance from the fusion line to the precrack and HAZ ratio on the precrack

-0.4 -0.2 0 0.2 0.4 0.60

20

40

60

80

100

HA

Z r

ati

o o

n t

he

pre

cra

ck

(%

)

Average distance from the fusion line to the precrack (mm)

●: GMAW 0.5kJ/mm△: SAW 1.6kJ/mm

In both case of 0.5kJ/mm GMAW and 1.6kJ/mm SAW; Average distance from the fusion line to the precrack should be keep 0.2 mm or more to keep the HAZ ratio on the precrack more than 80 %.

Trial test results



19

CTOD test results

-20 -10 00.05

0.1

0.5

1

5

Temperature (deg.C)

CT

OD

va

lue

(m

m)

CGHAZ

●:δm△:δu

-20 -10 0

Etched HAZ

GMAW 0.5kJ/mm

-20 -10 00.05

0.1

0.5

1

5

Temperature (deg.C)C

TO

D v

alu

e (

mm

)

CGHAZ

-20 -10 0

Etched HAZ

SAW 1.6kJ/mm

●:δm△:δu

Measured CTOD values were more than 0.25 mm.

Trial test results



20

Charpy impact test results

The transition temperature of CGHAZ in 1.6kJ/mm SAW joint was higher than 0.5kJ/mm PGMAW joint.

-60 -40 -20 00

100

200

300

400

Ab

so

rbe

d e

ne

rgy

(J

)

Temperature (oC)

PGMAW,0.5kJ/mm

CGHAZ EtchedHAZ

0

50

100

Sh

ear

are

a (

%)

CGHAZ vTs: <-60 oC

Etched HAZ vTs: <-60 oC

-60 -40 -20 00

100

200

300

400

Ab

so

rbe

d e

ne

rgy

(J

)

Temperature (oC)

SAW, 1.6kJ/mm

CGHAZ Etched HAZ

0

50

100

Sh

ear

are

a (

%)

CGHAZ vTs: -35 oC

Etched HAZ vTs: -53 oC

Trial test results



21

Hardness distribution in 0.5 kJ/mm GMAW joint

1.5mm -0 / +0.5mm

1.5mm -0 / +0.5mm 1mm 0.5-1.0mm

-15 -10 -5 0 5 10 15150

175

200

225

250

275

300

Vic

ke

rs h

ard

ne

ss

(H

v 1

0k

gf)

OD Straight OD Bevel ID Straight ID Bevel

Distance from fusion line (mm)

Fusion line

PGMAW 0.5kJ/mm

Significant hardening occurred at CGHAZ near the outer surface. Near the inner surface, hardening was not significant.

Trial test results



22

0 5 10 15150

175

200

225

250

275

300

Th

rou

gh

th

ick

ne

ss

h

ard

ne

ss

dis

trib

uti

on

o

f F

L+

0.4

mm

(H

v 1

0k

gf)

Bebel side (Last pass side)

Distance from outside surface (mm)

PGMAW, 0.5kJ/mm

HAZ of Cap pass

Max. 307

It was confirmed that significant HAZ hardening occurred only in the cap pass region

Hardness distribution in 0.5 kJ/mm GMAW joint

Trial test results



23

Hardness distribution in 1.6 kJ/mm SAW joint

1.5mm -0 / +0.5mm

1.5mm -0 / +0.5mm 1mm 0.5-1.0mm

No significant hardening occurred at CGHAZ.

-15 -10 -5 0 5 10 15150

175

200

225

250

275

300

Vic

ke

rs h

ard

ne

ss

(H

v 1

0k

gf) OD Straight

OD Bevel ID Straight ID Bevel

Distance from fusion line (mm)

Fusion line

SAW, 1.6kJ/mm

Trial test results



24

4. Summary

• NSSMC is conducting test procedure development to evaluate pipe properties (especially CTOD properties) at HAZ in girth welded portion based on API-RP-2Z • Outlines of developing procedure and trial test results were introduced. NSSMC will continue to develop the test procedure to obtain broad consensus with our customers.

Documents

Study on test procedure development to evaluate pipe ...mycommittees.api.org/standards/api1104/Meeting Materials/2013...test procedure development to evaluate pipe ... API 5L X65QO