SS- Filler Wire Selection

7/26/2019 SS- Filler Wire Selection

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Stainless Steels:Filler Metal Descriptions

and Welding Data:

STAINLESS GAS FACT:The biggest selling gas mix inNorth America for MIG, stainless sheet metalapplications, is a tri-mix containing argon - helium andCO2. The weld reality. For most gage stainlessapplications, the tri-mix provides more disadvantagesthan benefits in contrast to a less costly two part mix,argon with 2 - 4% CO2.

Stainless Steel "MIG Gas Reality"

Fifteen years ago while working with AGA, a SwedishIndustrial gas manufacturer located in Ohio I carried outextensive, stainless MIG gas research. I found out aremarkable gas fact. If you take the helium out of the heliumtri-mix developed for stainless short circuit applications, youachieve remarkable advantages for thin gage stainless. From


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this research I developed an optimum gas mix for both shortcircuit and spray transfer stainless steels. Argon with 2- 4 %CO2.

STAINLESS SPRAY APPLICATIONS >0.080:For many years I have been advising the stainlessmanufacturing companies I dealt with to use argon with 2 - 4%CO2. This mix is superior to argon oxygen mixes for stainlessMIG spray or pulsed applications. In contrast to an argonoxygen mix, an argon 2 - 4 % CO2mix results in cleaner, (lessoxidized) welds on stainless applications > 5 mm, this is verybeneficial on multipass welds, welds in which porosity is aconcern, or welds in which the cosmetic appearence isimportant.With the argon - CO2 mix, you can expect cleaner welds andwelds with less weld porosity, also the carbon pickup of thisgas mix will not impact low carbon steel stainlessconsumables.

STAINLESS SHORT CIRCUIT APPLICATIONS


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WHAT IS STAINLESS?

STAINLESS COMES IN MANY FORMS IT CAN BE

A LOW COSTMETAL WITH A LITTLE CHROME A LOT OF IRON.

Austenitic Martensenitic and Ferritic.Austenitic Stainless Steels are the ones we are most familerwith. These chrome nickel steels, in contrast to the lower coststainless have more alloys and are "non magnetic" Exception,types 310 - 330

Austenitic steels. Grades 20-202-205-301-302-303-304-305-308-


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309-310-314-316-317-321-329-330-347-389-17 7PH- 17 4PH-PH15-7Mo-AM 350-AM 355 A 286.

304 (S30400) - 304L (S30403) - 316 (31600) - 316L (S31603) -347 (34700)

Austenitic Facts: Austenitic grades typically 18% chrome

8%nickel (18/8).Grades 301-302-304-305-308 usually welded with E308

18/8 grades used for machine parts exterior buildings andindustrial parts.

18/8 not to exceed 800F 426C service temperature.

Manganese grades of stainless "200" series similar to 18/8

grades. Manganese in this series is used for "extra strength"Welding the manganese grades usually use the E308L filler.|

Martensitic and Ferritic are commom grades that we dont wantto weld and if we do we weld with great caution.

Note when welding these grades the weld procedure focus willbe on HEAT treat


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STAINLESS INTERNATIONAL WIRE SPECS

US AWS A5.9 / UK BS2901 / Japan JIS Z3321/ ISO3581/ Germany DIN 8555 - 8556

UNS International filler metal numbers start withWXXXXX

TYPICAL

STAINL


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ESSFILLERMETAL

S

Stainless Filler Metal Information:

StainlessFiller

InternationalSpecs

ChemistryManufacturesdesignations

Applications

Electrode

E308

Germany SGX5 Cr Ni 19.9

ISO 23.12

UNS W30940

C 0.08Mn 1 - 2.5

Si 0.25-0.6Ni 9-11

Cr 19.5-22

Thyssen-ThermJ

Kobe-MGS

Lincoln L18.8Pacweld -PW176SS

Sanvik 19.9

E308 istypicallyused whenthe

corrosiveconditionsare notsevere

Electrode

E308L

(low

carbon)

Germany SGX2 Cr Ni 19.9

ISO 119.9L

UNS W30843

C 0.03Mn 1 - 2.5Si 0.25-0.6

Ni 9-11Cr 19.5-22

ESAB -OK16.10Thyssen -JE

Sandvik 19.9L

Note (L)the lowercarbon toavertcarbideprecipitation

Electrode

308LSi

ESAB- OK

16.12Thyssen - JESi

Sandvik19.9LSi

Filarc -PZ6061/6561

TREFIL2PPSG

Note Si or

HiSi The highsilicon

increases thearc stability

and the weldwetting, which

is importantfor the low

amp, sluggish,

short circuitwelds

Electrode

309

Germany SGX12 Cr Ni

22.12

ISO 23.12

C 0.012Mn 1 - 2.5

Si 0.25-0.6Ni 12-14

Cr 23-25

ESAB- OK16.53

Sandvik- 24.13Thyssen -

Therm 25.14

Used firwelding 309

and austeniticto ferritic

(carbon) steels


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UNS W30940

Electrode

309L

C 0.03Mn 1 - 2.5

SI 0.25-0.6Ni 12-14

Cr 23-25

Used for weldoverlay

applications orbutter passes.

Electrode

310H

C 0.10 -0.12

Cr 26Ni 22

(H) Hasminimum

carbon contentlower carbon

can causemicro

crackingcausing tensile

reductions

Electrode

310

Germany SG

X12CrNi 25.20

ISO 25.20

UNS W31040

C 0.08-0.15

Mn 1 - 2.5Si 0.25-0.6

Ni 20-22.5Cr 25-28

To weld 310

and 304 cladand stainless

overlay

For low or high temp, corrosive or

any critical applications alwaysconfirm electrode choice with wire

manufacturer.

Using ELC ensure weld gas has less

than 3% CO2.

A low co2 mix is less oxidizing than a

low oxygen mix.

For l;ow carbon base use low carbon

filler identified by EXXXL

Electrode

312

GermanySG 9250XRCUNS W31240

ISO 29.9

C 0.15

Mn 1 - 2.5Si 0.25-0.6

Ni 8-10Cr 28-32

Higher Ferrite.More "crackresistance"

than E309.


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Electrode

316

GermanySG9250ZRC

UNS W31640

ISO 19.12.2

C 0.08Mn 1 - 2.5

Si 0.25-0.6Ni 11-14

Cr 18-20Mo 2-3

ESAB- 16.35Thyssen -

Therm G.Sandvik

19.12.2

for 316 steelsand good for

"high temp"corrosion

resistance

Electrode

316L

Germany SG

X2 CrNiMo19.12

ISO 19.12.2LUNS W31643

C 0.03

Mn 1 - 2.5Si 0.25-0.6

Ni 11-14Cr 18-20

Mo 2-3

Electrode

317L

317 GermanySG CrNiMo

1813ISO 19.13.4

UNS W31740

317L UNS

31743

C 0.03Mn 1 - 2.5

Si 0.3-0.65Ni 13-15

Cr 18.5-20.5

Mo 3-4

Has moly toincrease the

tensilestrength. Has

excellentcorrosion

resistance andhigh temp

propertiesNote contains

considerableferrite which

can lowertoughness

properties.

Electrode

318

Germany SGX5

CrNiMoNb1912

Electrode

320

used forwelding

Carpenter 20plus 20Cb-3stainless

Electrode

321UNS W32140

C 0.07Mn 1.43

Si 0.58Ni 10.52


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Cr 18.58

For weld data and information on CarbidePrecipitation scroll down to weld data

Electrode347

Germany SG

X5 CrNiHb

1999UNS W34740ISO 19.9No

C 0.069

Mn 1.59

Si 0.49Ni 9.96Cr 20.82

ESAB 16.11

Thyssen Therm

H.Sandvik -19.9Nb

used for 321 -

347 bettercorrosion

resistance than308

E347-321 wireis stabilized

with smallamounts of Ti

or Cb toprevent

carbideprecipitation

Electrode349

UNS 34940

Electrode

410

Germany

SG 5 350UNS W41040

ISO 13-EZ13-189

Electrode

430

GermanySGS 250 Zr

ISO 17 - EZ17UNS W43040


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Welding High Strength, High Carbon

Steels withAustenitic Stainless or Nickel FillerMetals.

Austenitic and specific nickel filler metals can offer manywelding benefits for welding dissimilar joints.

In welding high strength, high carbon steels the austenitic /nickel filler metals offer unique features that can reduce weldcrack potential in both the welds and weld heat affected zone

(HAZ).

[1] High carbon to stainless welds require that the stainlessweld metal have sufficient ferrite to resist cracking. Whenwelding carbon steel to stainless and a 309Lwire is used, theresulting ferrite is approximately 14-16FN.

If the steel is a high carbon steel, a 309L, first weld pass on thecarbon to stainless will likely end up with "insufficient ferrite".The carbon from the high carbon steel when mixed with thestainless weld will suppress the ferrite formation. Instead of

the 309L for this application, a 312 electrode may berecommended.

The 312 filler metal, (70 to 90 FN in the weld metal) producesmuch higher ferrite levels than the 309L. This is the primereason the 312 is recommended for applications sensitive toweld cracks.Filler metals such as 307 - 308 Mo and 310 can


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resist cracking with the aid of alloys and without the aid offerrite.

[2] High carbon, high strength steels welded to each aresubject to hydrogen assisted cracking. [1] High hardness, [2] a

source of hydrogen and [3] high stresses, these are the threefundamental requirements for hydrogen assisted cracking.

[a] With the high carbon steels, high hardness is typical in theHAZ unless very high, (not practical) preheat and interpasstemperatures are utilized for the welds.

[b] The stresses that can influence HAZ cracking typicallyresult from weld residual stresses caused by weld shrinkage,these stresses can be further exaggerated by weld jointrestrictions as found in certain fixtures.

[c] As we are all aware hydrogen in the weld can be derivedfrom many sources.

An alternative to a high carbon, high strength filler metals, inwhich the carbon dilution from the base metal will result in ahard weld, subjecting the weld to transverse cracking, is anaustenitic or a specific nickel based filler metal (ENiCrFe-2).

The austenitic or nickel filler metals greatly reduces the weldtransverse cracking potential. Also these filler metals greatlyreduce, slow down or trap the weld hydrogen that can diffusefrom the weld into the HAZ, this greatly reduces HAZ hydrogencracking potential.

The diffusion of hydrogen though austenitic and nickel fillermetal welds and steel can be approximately 80 - 110 timesslower than through carbon steels and welds. The use of theaustenitic and nickel filler metals can greatly reduce crackinghowever these filler metals can still absorb hydrogen so theseelectrodes should be treated with the same respect and rulesthat apply to any low hydrogen filler metals.


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In North Americaand the World, Sanvik setsthe standard for MIG Stainless wires.

Excellent stainless gas shielded flux cored wires are

available from Alloy Rods and Kobleco.

ELIMINATE STAINLESS WELDPOROSITY:

Weld porosity, a cavity discontinuity that forms from a gas

reaction. The porosity can be trapped in the weld or at theweld surface. The porosity is typically round in shape but canalso be elongated

ROBOTS AND MIG POROSITY.When you find the robot weldporosity is always at the same location and the weld porosityis not at the weld starts or ends, examine the robot movementand see if the robot arm is causing a restriction of the gas flowline. Also it's common with robot cells to see a severe gas flowrestiction due to the narrow orrifice found in gas line

connections. In a robot cell its critical to measure gas flow asit exits the gun. If the porosity is at the weld start or stopincrease the gas pre flow and post flow times.

WELD POROSITY:Weld porosity, a cavity or discontinuity that forms in the weldfrom a gas reaction in molten metal.

The weld porosity can be trapped in the weld or evident at theweld surface. Weld porosity is typically round in shape, butcan also be elongated.

Weld porosity is caused by the absorption of oxygen, nitrogenand hydrogen into the molten weld pool. The gases are thenreleased on solidification and may become trapped in the weldmetal.


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Nitrogen and oxygen absorption in the weld pool usuallyoriginates from inadequate or contaminated gas shielding,leaks in the MIG gas line, excess gas flow rates, draughts andplate contamination.

Hydrogen can originate from a number of sources includingmoisture from the electrodes,moisture on the parts,contaminates on the workpiece surface.

CLUSTER WELD POROSITY. A localized groupof pores with random distribution. Causes. Arcblow, insufficient, inconsistent or excessive

weld gas flow, material or weld wire contamination, (low) weldparameters or poor technique.

PIPING, WORM HOLE, WAGGON TRACKS POROSITY.

Sometimes called "waggon tracks". Typically found in thecenter of the weld, parallel to weld axis. Classic porosity whenmoisture is evident in gas shielded flux cored wires, (thecheaper the product the more prone to waggon tracks).

Increasing the flux cored wire stick outand increasing the wire feed rate helps byadding energy to the wire. Baking fluxcored wires and storing the wires in a dryenvironment also reduces potential. Slow

weld speeds, make welds larger, avoid weaves. Allrecommendations are intended to increase the weld arcenergy and decrease the weld cooling rate.

Worm holes are elongated gas pores producing a herring boneappearance on a radiograph. Worm hole porosity is commonin gas shielded flux cored welds when the electrodes have toomuch moisture in the wire flux.

WELD ROOT POROSITY.Weld root porosity frequently occurs when MIG welding using"argon oxygen" (oxidizing) mixes on parts >6 mm. With thesegas mixes the resulting root is typically narrow, finger shaped.The root finger area solidifies rapidly trapping porosity. Toreduce the stainless root weld porosity, change to an argon 2 -4 CO2 gas mix. Increase the weld parameters, slow the weldspeed and avoid weld weaves.

ALIGNED WELD POROSITY. Linear porosity, an array of smallround pores typically found in a line. Often caused from thebase metal lubricants or metal surface contaminate. Add weld


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energy (increase wire feed), increase push angle allowing thearc to break up surface oxides ahead of weld.

SCATTERED WELD POROSITY. Weldporosity scattered randomly throughout the

weld or welds. If the MIG weld surface isgray and looks oxidized, the porosity istypically a result of insufficient gas flow. If

the weld surface looks clean with scattered porosity theporosity is usually caused by the base metal part or electrodecontamination, or perhaps the weld data used causes the weld

to freeze too rapidly.

LARGE PORE WELD POROSITY.If weld surfaceis clean and does not look oxidized, the largepore MIG / FCAW porosity could be a result of

excessive gas flow. Gas turbulence is caused with gas flowgreater than 40 cuft/hr. Optimum MIG and flux cored gas flowfor carbon steels is 25 to 35 cuft/hr, the gas flow should bemeasured as it exits the gun nozzle. If the weld surface is dirty(oxidized) the cause of larger pore porosity is ofen a result ofinsufficient gas flow, less than 20 cuft /hr.

Jan 2004. Sandvik Announces New Ultrahigh- Strength

Stainless Steel "NANOFLEX":

Sandvik Materials Technology recently developed anew stainless steel called Sandvik Nanoflexthatfeatures ultrahigh strength and good formability,corrosion resistance, and surface finish. According tothe company, the steel is well suited for mechanicalapplications requiring lightweight, rigid designs suchas medical equipment and for replacement of hard-

chromed, low-alloy steels in the automotive industry.

Examples of the strength properties of Sandvik Nanoflex are 1700 MPatensile strength, 1500 MPa yield strength, 8% elongation, 45-58 HRC

hardness, and a Charpy V impact strength of a minimum of 27 J at -20C.Exact strength values depend on the product form and the manufacturing

route.


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Despite its high hardness, the company claims it is easy to perform coldforming operations such as bending, cutting, turning, and grinding. After

reaching the desired shape, a simple low-temperature heat treatment givesthe material its high strength without distorting the workpiece.

This material also displays good welding properties. It isavailable in tube, strip, wire, and bar forms.

Stainless Filler Metal SelectionStainless Type FILLER METAL

SELECTIONAWS A5-9. Usefirst choice.

Confirm choicewith wiremanufacturer

AUSTENITIC CHROME NICKELNONE MAGNETIC

Stainless 201to austenitic 200-300series use

201 used for low temp cryoapplications to -320F

308For 330 use 312

Stainless 202 to austenitic 200-300series use

308For 330 use 312

Stainless 201-202-301 303 to mildsteel use

312

Stainless 210 - 202 -301 to mildsteel use

312


308For 330 use 312

Stainless 302to austenitic 200-300

series use

308

For 330 use 312Stainless 302 - 302b 304 to mildsteel use

310

Stainless 302 - 302B -304 to mildsteel use

310


308For 330 use 312


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Stainless 303 to 310-314-330- use 312

Stainless 303 to mild steel use 312


308For 330 use 312


Stainless 305 to austenitic 200-300series use

308For 330 use 312

Stainless 305 - 308 to mild steeluse

312

Stainless 308to austenitic 200-300

series use

308

For 330 use 312

Stainless 309to 309 - 310 - 314 -316 - 317 use

309

Stainless 309 to 330 use 312

Stainless 309 to 347 use 308 - 347

Stainless 310to 310-3140 310






Stainles 310 to mild steel use 310

Stainless 314to 314 use 310



Stainless 314 to 321 308





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Stainless 316to 316 - 317 use 316

Stainless 316 to 321 - 347 use 308

Stainless 316 to 330 312 - 309

Stainless 316L to mild steel use 309

Stainless 316LN a nitrogenaddition to a low carbon stainlessIncesase both corrosionresistance and strength ascompared to 316L

316L or 317L317L typical forcorrosion316L for toughness(cryogenic typeapplications

Stainless 317to 317 317



Stainless 317 to 347 use 308L

Stainless 317 - 321 - 348 403 - 405410 414 416 to mild steel use

309

Stainless 321to 321 - 347 347



Stainless330to 347 use 312 - 309

Stainless 348 347

Stainless 384 309

Stainless AM 350 AM 350

Stainless 410 Condition AASTM 27612% Chrome, chrominum /martensitic steel

to itself or carbon309L


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Stainless 501502 430 431 442 448to mild steel use

310

17-7PH use W17-7PH

PH15-7Mo use WPH 15-7Mo

17-4PH use 17-4PH

A286 A286

Sanicro 2827 Cr - 31 Ni -Mo 3.5 -Cu 1Tensile 73 ksi Yield 31 ksi

Sanvik 27.31.4.LCuER028L

Duplex Ferritic Austenitic

SAF 2304UNS 32304DIN X2CrNiN 24-423 Cr - 4 Ni - N 0.1Tensile 87 ksi - Yield 58 ksi

308 MoL

Duplex Ferritic AusteniticSAF 2205UNS S31803

22 Cr - 5.5 Ni -Mo 3 - NTensile 990 ksi - Yield 65 ksi

Weld Note: For MIG use argonwith 2% CO2. When welding 2205or 2304 to dissimilar butter firstwith ER309MoL then weld with308MoLNo concern for interpass temp,high amps can be use

2209

Duplex 3RE60

18.5 Cr - 4.9 Ni - 2.7 Mo weld same as 2205

254 SMO alloy

Electrode Avestap12Sanvik Sanicro 60ENiCrMo3

Stainless to carbon309 or 312 which hashi her ferrite


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reduces cracking

MARTENSITIC STEELS403 - 410 - 414416- 420- 422 -431- 440

Preheat and interpass temp 500F 260CPost heat 1350F 732C>Control cool 50F / hr to 1100F>Control cool to 1100F 600C then air cool.Treat the 500 series the same as theMartensitic series

Stainless 403 to 400 series use 410 ASTM 276


Stainless 403 to 505 use 505Stainless 405 to 505 use 505



Stainless 405 to 400 series use 410

Stainless 410 to carbon steel 309L

Stainless 410 - 414 WELD same as405

Stainless 416 - 440 butter with 312or 309 first

Stainless 416 to 505 -502-501 -446- 440 -430 -420 use

309

Stainless 416 to 431-420-416 use 410


Stainless 420 to 501-502 use 502


Stainless 420 to 440 -420 use 420




Stainless 430 to 446 - 440 - 431 -430 use

430


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Stainless 430F to 400 series use 309



Stainless 431 to 446-440 use 309

Stainless 440 weld same as 431





Stainless 501 to 505 - 502 - 501use

502

Stainless 502 to 505 - 502 use 502Ferritic steels 405 - 409 - 429 - 430-434 - 436 - 442 -444 - 446

444 to 444 or to other metal use 316L or 309MoL

Ferritic magnetic avoid prolongheat in the range of 750F -1700F(400-925C

Feritic preheat at 350F 176C Toimprove ductility

Ferritic steels most frequentelectrodes 309 - 310 - 312

Ferritic steel if post heat requireduse Austenitic filler

Stainless and Nitrogen PurgeGas Question.

Ed as you are aware Nitrogen is a lotcheaper than argon when utilized as apurge gas for stainless. My question,When MIG welding stainless tanksedge or corner welds, tube or pipe


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open root welds, can nitrogen react with the stainless andhave a negative impact?

Answer: Nitrogen typically a diatomic, "two atoms" permolecule. Nitrogen in the diatomic form is usually insoluble in

molten stainless. However if the nitrogen gets into the weldarc, the plasma arc energy can seperate the diatomicmolecules and create monatomic molecules.

The monatomic molecules are soluble in the weld. Thenitrogen, monatomic (seperated molecules) become analloying element and can reduce the ferrite in a stainless weld.A reduction in ferrite in some alloys can cause the weld to bemore austenitic and sensitive to hot cracking. If nitrogenenters a weld or the welding arc, it can have a negative andsometimes a positive influence.

There are stainless alloys which do not need ferrite like 320 /310. With these alloys nitrogen has no negative impact onthese alloys. Also if the stainless alloys have high ferrite levelsthey typically can afford to loose a little of the ferrite to thenitrogen.

With closed root, austenitic stainless welds, as found in tanks,corner, edge welds, or thin gage, partial penetration tubewelds, nitrogen is the logical, economical, purge gas choicefor all austenitic, duplex, martensitic and precipitationhardening stainless steel applications. The only concernwould be a few specific, ferritic alloys in which nitrogen couldcause severe weld mechanical issues.

With an open root "MIG stainless weld"the nitrogen purge gas has littleopportunity to get into the weld arc as thegas flow rate / pressure of the welding gasshould be higher than that of the purginggas . However nitrogen could still bepicked up by the weld. .

With duplex stainless there should be noconcerns for open root nitrogen issues.The majority of the common, open root

stainless alloys will not be adversely affected by nitrogenpurge gas. However in the world of product liability, here is thewelding bottom line. If your weld job is large enough toproduce a substantial cost reduction from using nitrogen gas,


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then it's logical to "pre qualify the nitrogen purge welds"andhave the weld chemistry, ferrite and mechanicals tested.

Failed Pipe Weld Tests.

Question: Ed we weld austenitic stainless and carbonsteel pipes. For cost reduction, in our stainless weldtests we only utilize "carbon steel pipes" and 309LSMAW or flux cored, electrodes. We frequently haveroot cracking issues, or during the bend test the weldsample breaks. What is strange is that we visuallyexamine all the roots and we wont let them bemechanically tested unless the welds look OK. Why

the inconsistency? why do some tests welds pass andother good looking welds fail?

Answer: The bottom line the 309L electrode is designed toweld "carbon steel to stainless" this electrode was notdesigned to weld carbon steel to carbon steel thats why wehave carbon steel electrodes.

Use the 309L electrode on two carbon steel pipes and welddilution becomes a concern in the weld root area. If the weldparameters and edge prep is such that the resulting weld

dilution is minimal, the resulting 309L weld should beaustenite with a little ferrite. It's the austenite / ferritecombination that provides weld ductility.

If while welding the carbon steel pipe root, the welder useshigher current, slower weld speeds or a wider weld weave, the309L weld can end up with more weld dilution with the carbonsteels, reducing the weld ferrite level and making the weld


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more austenitic. A reduction or loss of ferrite can make theweld subject to "hot centerline cracking" (hot cracking, theweld cracks during the weld or soon after).

A hot weld crack surface in a bend test can be identified by a

blue or gray color. Even if the root pass does not crack thehigh austenite composition can turn to martensite whencooling. The brittle martensite can readily fracture during thebend test. (a silver color or bright fracture surface).

The bottom line if you look at the costs involved in thestainless to carbon steel pipe weld test, it makes little sense touse two carbon steel pipes. Ensure for your weld test that oneof the test pipes is at least stainless.

StainlessWeld Data.

When MIG Welding stainless you can use the optimum MIGwire feed data recommended at this site for carbon steels. Theonly change that will be required is weld voltage. As stainlesswill use a low reactive gas mix, less weld volts will be required.For MIG stainless welds typically 2 - 3 lower volts are requiredthan that recommended for carbon steels.

Keep stainless clean, only use stainless wire brushes.

Manganese grades usually weld wiith a 308L

Welding XXXLensure filler is low carbon as designated XXXL


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With fixtures avoid carbon steels inclose proximity to stainless welds,as carbon pick up possible, the

weld area will rust. There are manyways to introduce carbon tostainless welds.For stainless vert up welds onparts 3 to 6 mm, consider pulsed,

For stainless all position welds on parts > 6 mm, first logicalchoice will be always be stainless gas shielded flux coredwires.

Minimize the drive roll tension applied to stainless flux cored

wires.

For stainless flux cored weld data, use the carbon steel fluxcored wire data found in my flux cored book.

For stainless flux cored use an argon mix with 15 - 25 CO2.

STAINLESS AND CARBIDE PRECIPITATION (chromedepletion):

Use weld data to avoid CarbidePrecipitation. (CP)

For stainless corrosive environmentscontrol of CP is critical.CP occurs with 300 series in thetemperature range of 800F - 1600F,430-870C.CP typically occurs within 3 mm ofeither side of a weld HAZIn the temperature range of 800-1600Fthe chrome will move to join carbon,

this results in "chrome depletion"leaving an area with less

chrome.

A chrome depleted area may not resist the corrosiveenvironment.

To combat CP use (L) low carbon base and filler metals.

Ensure the C02 gas composition has less than 5 % CO2.


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Stainless and stabilized electrodes.You can combat CP with stabilizedfillers which provide alloys that grabthe carbon before it can affectr thechrome. Alloys like E347 which work

at reducing chrome depletion.Stabilized fillers are typically used inhigh strength high temp service.However if base metal is not an Lgrade CP will occur.Rapid cooling of stainless through

the 800 - 1600F range reduces Carbide Precipitation.

TIG welding and the influenceof "sulfur" in austeniticstainless.When the parts to bewelded have normal sulfur content(greater than 0.005%) aninteresting event can occur. Withincreasing weld temperature thesurface tension of the weld poolalso increases. The result is the

hottest part of the fluid weld surface is attracted to the middle

of the weld pool causing deep narrow weld penetration.

With lower sulfur in the weld, the weld surface tension is less.The resulting weld is wider with less fusion. When two partswelded together have different levels of sulfur tension the weldmay pull towards the lower tension, lower sulfur part, resultingin inconsistent weld fusion or penetration favoring one side ofthe weld joint. This occurrence is especially notable whenautomated TIG welding Dissimilar parts such as cast parts tosheet or pipe. The following weld solutions may assist thesulfur issues.

[1] Pulse the application.[2] Use a weave.[3] Weld twice.[4] Use heat sink back up bars in close proximity to weld.

General Stainless (P-8) 300 Series Pipe Weld Procedure Data.Max interpass Temp 350F


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ProcessTungsten

Thoriated

Filler

DiameterMetal Polarity Amps

Wire

FeedVolts

GTAW 3/321/16 -

1.6mm

300

series

Stainless

DC

Straight95-145 N/A 14

SMAWEXXX-15-16

1/8

3.2mm

300

series

Stainless

DC

Reverse95-145 N/A 20-24

SMAWEXXX-15-16

5/32

4mm

300

series

Stainless

DC

Reverse125-175 N/A 21-25

FCAWEXXX-T1

argon with

25 CO2

045

300

series

Stainless

DC

Reverse

130-180

(140)230/280 22-25

SS- Filler Wire Selection

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Transcript of SS- Filler Wire Selection