Corrosion Resistance and Weldability a Challenge for ... · 266 279 272 287 272 277 262 276 253 265 287 x 271 269 293 273 261 291 283 279 296 280 271 292 296 294 276 281 x 285 274

voestalpine Böhler Welding1 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019www.voestalpine.com/welding

voestalpine Böhler Welding

Corrosion Resistance and Weldability a Challenge for Duplex Filler Metals

TRUSTED IN EXTREME CONDITIONSPUSHING STEEL SOLUTIONS

TO NEW LIMITS VOESTALPINE OIL AND GAS

ABERDEEN, JUNE 2019

Bernd HobergGlobal Application Engineeringvoestalpine Böhler Welding GroupHamm, Germany

voestalpine Böhler Welding2 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019

vaBW Germany / Hamm

Annual capacity: 48,000 tons solid wire, flux


Content:

Characteristics of DSS and SDSS

Welding Procedures vs. Tendency to Pore Formation

Corrosion Testing

Conclusion



DSS 2205 type – UNS 32205

SDSS 2507 type – UNS 32760

incr

easi

ng c

orro

sivi

ty o

f wat

ers

904L - X2CrNiMoCu20-25

317L - X2CrNiMo18-15-4

316L - X2CrNiMo17-12-2

304L - X2CrNi19-11

6%Mo Super Austenitic Stainless Steels 926L - X1NiCrMoCuN25-20-7

Titan: grade 2, grade 12

Nickel Alloys: Alloy 625, C-Alloys, e.g. 59,C-276, C 22 etc.

„ Stainless Steels:Austenitic Stainless Steels

Material Selection – e.g. for Seawater Environments

resistance against seawater at ambient temperature


ASTM A 923-8

corr. test temp.* BM + WM:22°C/24 hCVN -40°C BM, HAZ: 54J, WM 34 J*) detection of intermetallic’s e.g.

sigma phase

NACE MR 0175-2003 PREN Cr%+3,3(Mo+0,5W)+16N%

30 ≤ PREN ≤ 40: ferrite 35-65%H2S: 10kPA

Max. working temp 232°C Cast and wrought products

ASTM G 48 A – 2003

Methode A: 6 mass-% FeCl3CPT: 25°C/24 h WM + BM

NORSOK MDS 42(rev.5)UNS S31803, UNS S 32205Ferrite 35 - 65% WMRp0,2 > 450, Rm > 620MPa,A > 25%CVN -46°C > 45J

CPT G 48 A: 25°C/24h WM< 4g/m2 WM

NORSOK M-601(2016)Ferrite 30 to 70% WMCVN -46°C: 27 J WM+FLHardness max 36 HRC(DIN EN ISO15156-3)

22Cr - DSS Interactive Requirements


NACE MR 0175-2003PREN Cr%+3,3(Mo+0,5W)+16N%

40 < PREN ≤ 45; ferrite 35-65%H2S: 20 kPA

Max. working temp 232°C Cast and wrought products

NORSOK MDS 52 (rev.4)PREN Cr%+3,3Mo+16N% ≥ 40Ferrite 35-65% WMRp0,2 >550, Rm >795MPa, A > 25%CVN -46°C > 45JCPT: ASTM G48 A: 50°C/24h

no pits, < 4,0 g/m2 => WM/BM

ASTM G 48 A + E – 2003A: 6 mass-% FeCl3E: 6 mass-% FeCl3 +1%HClCPT: BM and WM

Start temp 20°C / 24h ∆T: 5°C / 24 h

NORSOK M-601(2016)Ferrite 30 to 70% WMCVN -46°C: 27 J WM + FLCPT ASTM G 48 A: 35°C/24h WM

no pits, < 4,0g/m2 WMHardness max 36 HRC (DIN EN ISO15156-3)

25Cr - SDSS Interactive Requirements

ASTM A 923-8corr. test temp.* BM: 40°C/24 hCVN -40°C BM, WM: negotiable! *) detection of intermetallicse.g. sigma phase


Content:



Corrosion Testing

Conclusion



GMA Welding / (MIG/MAG)Process: from manually

assisted to fully automaticShielding gases: inert/active; Ar, He and/or

CO2 and their mixturesAdvantages: high deposition rates and welding

speed, low heat input possibleDisadvantages: positioning of the torch, spatters

and weld defects e.g. lack of fusionand porosity SDSS PREN > 41)

Welding Consumables: Thermanit 22/09, Thermanit 25/09 CuTCN 22/9-IG CN 25/9 CuT-IG


Spray arcFine droplets without short circuitShielding gas: Ar and mixed gases e.g. Ar/He/CO2 - bal/30/0,5 Welding position: PA, PB Typical parameters: I = 270 A, U = 29 V 1.2 mm ø,

Vwire 8 m/min

Pulsed arcDroplet segregation through "pinch effect"Pulse time, voltage, current and pulse background must be adjustedShielding gas: Ar and mixed gases s.o.Base metals: CRA, nickel alloys, aluminum Welding position: PA, PB, (PF)

wireelectrode

magnetic field

reduction

of area

Influence of the Shielding Gas on Droplet Transfer and Arc Mode


• unalloyed structural steel(minor requirement)

• CRA, Super Duplex

• Nickel alloys

• low-mediumalloy steels

• CRA, Duplex

• Aluminium

Shielding Gases for GMA Welding acc. DIN EN ISO 14175Symbol

reducing inert reactiveCO2 O2 Ar He H2 N2

1 1002 1003 Bal. 0,5 ≤ 95 1 0,5 ≤ 5 Bal. a 0,5 ≤ 5 2 0,5 ≤ 5 Bal. a

3 0,5 ≤ 3 Bal. a

0 5 ≤ 15 Bal. a

1 15 ≤ 25 Bal. a

2 3 ≤ 10 Bal. a

3 0,5 ≤ 5 3 ≤ 10 Bal. a

1 25 ≤ 50 Bal. a

2 10 ≤ 15 Bal. a

3 25 ≤ 50 2 ≤10 Bal. a 1 1002 Rest 0,5 ≤ 30 1 Bal. a 0,5 ≤15 2 Bal. a 15 ≤ 50 1 1002 Bal. a 0,5 ≤ 53 Bal. a 5 ≤ 50

0 1 100

Z

M1

Shielding gas components in volume %oxidizing inertmain

groupsub

group

I

N

M2

M3

C R

Further subgroups are listed in DIN EN ISO 14175

Gas mixtures with components, which are not mentioned in this table or gas mixtures with compositions out of the specified range.

a) For this classification argon can be partially substituted by helium


Fluidity and arc stability lower than standard austenitic fillers (spatter)

Best results with synergic puls GMAW

Recommended shielding gas for SDSS:

Ar + 20-30% He + max. 0,5 % CO2

High BM nitrogen content influences sensitivity to porosity:

too thin or too thick beads increase risk

wrong joint preparation increases risk – high degree of fusion & trapping of nitrogen gas in solidifying metal

weld in a gap, root opening

Pulsed arc

Normal spray arc

Spatter in short arcSpatter in short arc

SDSS vs. 300 Series Stainless Steel - GMAW


Heat# 98162

Heat# 100073

Overlay welding: 2 layers, 4 runs

Pore Formation in GMAW of SDSS Weld Metal – Review 2010s


Super Duplex GMAW – Today

Pulse GMAW butt weld : Thermanit 25/09 CuT – Shielding gas:, Cronigon He 30 C (Ar/He/CO2 – bal / 30 / 0,25)

BM: UNS 32760 t = 15 mm, single - V groove 60 ° with backing run

X-ray acc. DIN EN ISO 10675-1 => acceptable 1

Heat# 104062


266279272287272277 262276 253 265

287 x 271 269293 273 261291 283 279296 280 271292 296 294276 281 x 285274 297 292 x284 292 279298 292 296

1 mm 308 1 mm 280 1 mm 289281 293 289272 304 303 x264 295 307277 302 296278 292 295285 296 x 275277 278 273282 275 273295 272 274277 270 253

285 x 269 269279 262 266280 264276284286274265

Gut

sche

Char

ge:

Char

ge:

C D

Pbz.

:

5822

42

ZNYD

1040

62

Auftr

agge

ber:

x: Schmelzlinie

MAG

/ Th

erm

anit

25/0

9 C

uT /

Ar+3

0%H

e+0,

25%

CO

2

Qua

lität

G

rund

wer

ksto

ff:

B C

BQua

lität

Sch

wei

ßgut

:

A

Schw

eiße

-

WEZ

-

GW

Schw

eiße

GW

-

WEZ

-

Sch

weiß

e

1.45

01 (U

NS

S327

60)

Seite 1 von 1voestalpine Böhler Welding Germany GmbH

Härteprüfung nach 6507-1

Har

dnes

sTe

st:

HV

10

Super Duplex GMAW – Today


YS[MPa]

Z[%]

TS[MPa]

A5[%] LoF

-- 835 -- BM

Sample

Flat tensile specimen # 1-- 834 -- BMFlat tensile specimen # 2

Tensile Test

149

CVN-2[J]

CVN-3[J]

CVNave[J]

Toughness CVN

PHWT

u

CVN

VWT 0/2

Test temp.[°C]

- 40 158 150143

CVN-1[J]

147uVWT 0/2 - 46 136 145153

25%Cr Duplex Butt weld – S 32760 t = 15 mm in PA Thermanit 25/09 CuT / Cronigon He 30 C

----


YS[MPa]

Z[%]

TS[MPa]

A5[%] LoF

739 885 58 WM

Sampole

Round tensile test RT559 559 62 WMRound tensile 220°C

Tensile Test

124

CVN-2[J]

CVN-3[J]

CVNave[J]

Toughness CVN

PHWT

u

CVN

VWT 0/2

Test temp.[°C]

- 46 123 124125

CVN-1[J]

133uVWT 0/2 - 60 136 130122

25,127,6

Mechanical Properties – All weld metal Thermanit 25/09 CuT / Cronigon He 30 C

Heat# 104062


DSS: Thermanit 22/09 + Marathon 431CN 22/9 IG + Flux 805*

SDSS: Thermanit 25/09 CuT + Marathon 431CN 25/9 CuT-IG + Flux 805*

*)PWHT solution annealing

Wire Flux Combination SA Welding


Features:

one wire electrode

one power source

one control

Advantages:

high deposition rate

Typical welding parameters: wire electrode diameter: preferred 2,0 mm - max. 2,4mmcurrent / voltage 240 - 350 A / 28 – 30 Vwelding speed: 45 - 50 cm/mininterpass temp: 100°Cheat Input: max. 12 kJ/cm flux: Marathon 431 (basicity 2,3 )

~ 25 mm

SA – Welding with SDSS Wire Electrode Thermanit 25/09 CuT


Chg.: 100419

Pore Formation in SA Welded SDSS All Weld Metal Sample

Chg.: 98376All weld metal test specimen acc. EN ISO 1597-1


Dimension Heat- no.

Sample-no.

C Si Mn P S Cr Mo Ni Al Cu N

UNS 32760 / 1.4501 6000x2000x15 L 74451 150316 0,025 0,27 0,51 0,021 0,002 25,2 3,62 6,94 - 0,54 0,22

Wire dia Flux

Thernanit 25/09CuT

- 100419 108JK 0,012 0,44 0,833 0,025 0,002 25,5 3,79 9,41 0,020 0,57 0,246

Thernanit 25/09CuT

Marathon 431

500x400x15 100419 / 1404784

XDM1 0,013 0,55 0,64 0,027 0,004 25,14 3,83 9,13 0,029 0,59 0,216

wire electrode

all weld metal

Base Materials

Chemical Composition

Weld metal

Test Specimen Remark

solution annealed 1120°C / 22 min / water

a) Chemical composition of base material and weld metal

Typical Properties SA Welded Sample


Typical Properties SA Welded Sampleb) Mechanical properties of base material and weld metal

c) Optical microscopy WM FL BM

Dimension Heat-no. Sample no.

ReH / Rp1,0 Rm A5 CVN

-20CVN -20

CVN -20

CVN -40

CVN -40

CVN -40

CVN -50

CVN -50

CVN -50

SBB 4,0

RBB 4,0

FBB 4,0

6000x2000x15 L 74451 150316 615 815 25 198 196 186

Wire Electrode dia. Flux

Thermanit 25/09 CuT 2,0 mm

Marathon 431

500x400 x15

100419 / 1404784 2K71 811

GW 132 58 70 80 52 76 77 64 67 180° OK

180° OK

180° OK all weld metal

Charpy Impact Test [J]

solution annealed 1120°C / 22 min / waterUNS 32760 / 1.4501

RemarkTensile Test Bend Test d/a

Test Specimen




Corrosion Testing

Conclusion

Content:



ASTM G 48 A - CRA test specimens will be examined in 6% FeCl3testing solution at constant temperature and testing time for example 24 h.

Pitting Corrosion

Crevice Corrosion

DSS

SDSS

Critical Crevice Temperature (CCT) - Critical Pitting Temperature (CPT)


Precipitation Behavior of (S)DSS

DSS SDSSCr 22,7 25,3Mo 3,3 3,7N 0,16 0,24

PRE >35 >41 YS (MPa) 630 732TS [MPA] 820 887Elong. [%] 30 26CVN [J],-40°C >100 >100

1000

300

M7C3 - CarbideCrN - Nitrid

σ - PhaseCr2N - Nitrideχ - Phaseγ 2 - Phase

M23C6 - Carbide

π - Phaseε - Phaseα - Phase

G - Phase

Time [h]

Tem

pera

ture

[°C

]

Mo, W, Si

CrMoWSi

Cr, MoCu,W

Cr, Mo, Cu, W

Properties of GTA weld metal:

DSS: Thermanit 22/09SDSS: Thermanit 25/09 CuT


Corrosion Testing acc. to ASTM G 48 ESample Preparation Machined test specimen, Final layer: as weld brushed cut edges ground with grid 80 wetASTM G 48, Method C and E 6 mass - % FeCl3 +1%HCl

Test 24 h (attn. method C ⇒ 72 h!) Start temp 20°C ∆T: 5°C/24 hDetection: Critical Pitting Corrosion (CPT)Calculation: Corrosion rates e.g. mm/year or g/m2


ASTM G 48 E - Results of various Thermanit 25/09 CuT Weld Deposits




Corrosion Testing

Conclusion

Content:



High thermal loading on the root pass increases the risk for:

precipitation of intermetallic phases !

reduced corrosion resistance

Cold-Pass HI: 8 - 12 kJ/cmBulky Root HI: 10 – 15 kJ/cm

HEAT INPUT =I x U x 60

VS x 1000 [KJ/cm]

Cold - Pass - Technique for SDSS


Slow cooling rate in the case of HI > 15 kJ/cm

Increased risk of precipitation of intermetallics (sigma, chi)

Structural instability

Decreased corrosion resistance

Decreased toughness

Avoid high heat input in hot pass to minimize sigma in root bead

Interpass temp. < 120°C for DSS< 100°C for SDSS

Influence of Heat Input

ColdPass

Bulky Root

HEAT INPUT =I x U x 60

VS x 1000 [KJ/cm]


Procedures and consumables: GTAW: wire rod PREN ≥ 41 (Norsok Calc.) for CPT requirements 35 - 40°C!

SAW: see above but don’t accept CPT > 35°C for joint welding (heat input !!!)

GMAW: wire electrode PREN ≥ 41 and appropriate shielding gas, FCAW is an alternative => Avesta FCW 2507/P100-PW NOR!

SMAW: PREN > 40 (Norsok Calc.) to achieve proper corrosion resistance

Welding practice and workmanship:Root and 1. and 2. layer: GTAWShielding gas: Ar + 2 %N2 (FM with PREN > 42 pure Ar to avoid porosity)

Purging gas: Ar + 2 %N2 or 95 N2 + 5 H2

Interpass temperature: max. 100°C

Heat input: root: 8 - 15 kJ/cm

layer 1. + 2. 5 - 12 kJ/cm

all others: 5 - 12 kJ/cm

Tack welding: welding on the root side not permitted

Welding of Super Duplex Steel

right handling ensuresa safe environment


Thank you!Bernd HobergT. +49/2381 [email protected]

Documents

Corrosion Resistance and Weldability a Challenge for ... · 266 279 272 287 272 277 262 276 253 265 287 x 271 269 293 273 261 291 283 279 296 280 271 292 296 294 276 281 x 285 274