A36 to 17-4 PH 309 slag inclusion issues

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I have been testing welders on a A36 to 17-4 PH stainless T-joint,  the mechanicals have passed BUT the Macro Etch does not.  I have had to re-test three people due to this.  I turned up the machine and its 130 amps on a 3/16 t joint with 1/8th inch 309-16.  Runs great and the welds looks great too.  When I view the testing the welder used sound techniques and had a well fused toe to toe.  I have elcosed the macros and a photo of the weld.  Chime in with any ideas please, Thanks!- Jordan Attached Images
Reply:Need all your parameters. Like metal thicknesses, Cover gas or flux type.  Wire diameter, cup size, position, preheat, the like.Those images make me think you are using fluxcore?  The root penetration is not there.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Metal thickness is 3/16, using a 309-16 1/8th inch SMAW process.  no preheat.  I have the same looking root as I did with 20 less amps, only thing left to do is crank it high I guess...  I mean the range on the electrode is 150 amps, for that thin of material 130 should be plenty
Reply:Originally Posted by MrWeldSoCalMetal thickness is 3/16, using a 309-16 1/8th inch SMAW process.  no preheat.  I have the same looking root as I did with 20 less amps, only thing left to do is crank it high I guess...  I mean the range on the electrode is 150 amps, for that thin of material 130 should be plenty
Reply:A couple thoughts:1 - Do the slag inclusions run the entire length of the weld bead?  Or are they intermittent?2 - Sometimes more amperage is not better.  Most of the stainless rods I'm familiar with recommend using the lowest settings practical.  McKay 309L rods have a maximum amperage of 120amps, with recommended settings for flat/horizontal down around 105 amps; for 1/8" electrodes.3 - I know it's slower, but try having your welders make the weld in 2 passes, not just one.The slag inclusions are all in the root.  There appears to be good, tight fitup, wiht no gap to trap slag between the plates.  So that means the slag is being buried in the weld bead.  Maybe too much amperage is gouging out the root and creating a cavity that grabs and holds the slag, rather than releasing it to float out.  Or maybe the puddle is too large/thick/deep to allow the slag to float out before the liquid metal freezes.These are just some suggestions for changes you could try to reduce the chances of this slag entrapment occurring.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:Are you running dc+ or dc- ?Lincolin Power Wave 450, Lincoln Powermig 255, Lincoln Pro Mig 140, Lincoln Squarewave Tig 275, Miller Big 40 G(with Hobart Hefty suitcase), Thermal Arc 95S and Esab PCM875 in an already full machine shop.
Reply:x2 on making two passes.It looks like a fairly large weave pass that would be over a small root pass.  Only no root was done.Based on the size of the face, the legs look overly long for 3/16" material.Without seeing anything in person - this is only guess.  Dave J.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:I just looked at the weld bead again, that's a strange looking bead.I looks like heat was held on the upper plate and molten metal just washed down on the lower plate?Anyone else think that's how it looks?Dave J.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:MinnesotaDave, that is how it looks and yea it was blasted from above a little more than from below, I have a little undercut on the top plate also.  I cannot teach them while I am testing them so thir own skills and technique.  I have to do something with the slag though, I read also somewhere that going to slow can cause slag to build up in front of the weld puddle and get sucked under the bead.  A DAB will do ya --   we cant run multiple passes, the test they are running is a single 1/8 welding rod on two dissimiliar metals.
Reply:@ propane hot rod we are running DC+
Reply:MrWeldSoCalAs DAB noted, the buried/lead flux doesn't seem to be floating out.  In addition to his suggestions, this is my best guess.Reading the bead in the first photo it looks like the rod is excessively laid forward [approaching parallel]. The higher the rod angle, the more round the bead ripples.The more acute the rod angle, the broader the flux-faceunder the rod, and greater the cross section of rod involvedin the arc  -  oval to pointed bead ripples.   Because you weld, I would run some coupons - varying the rod angle - and see if you could duplicate the problem.Opus
Reply:@ opus ferroThats a good point, I know a part they had was rejected and the welder told me he figured out a better rod angle after the fact.  Ill run a few samples myself and see what I come up with. Thanks for the input!!Jordan
Reply:Pic 2 - No penetration into the A36. just on the stainless side.  Welder ran the filler and arc onto the stainless and just let the (sluggish) puddle 'drip' onto the A36?Pic 3 - Undercut on the stainless, again minimal penetration of the weld into the A36 plate.Pic 4 - Undercut again, and again minimal penetration into the A36 plate.Pic 5 - Again, no real penetration into the A36 plate.Mostly incomplete fusion/penetration, probably due to travel speed being to slow or too fast.  Based on the rather large fillet size, I would guess from here that the welder ran too slow and just 'globbed' the filler onto the existing filler in the bead and didn't melt/fuse/penetrate into the base metal properly.Stainless SMAW electrodes are supposed to be stored and handled like low-hydrogen electrodes.  Use fresh from a sealed container or bake in rod oven at 500-600F for one hour and store in rod oven at 300F (per Lincoln).  Check for specifics about bake and storage temps with your specific rod manufacturer.Exxx-16 stainless rods list that they have a pretty heavy slag covering and "requires more care to avoid slag inclusions" (per Lincoln).Use a short arc!  No whipping or long arcing.  Similar to Exx18 low-hydrogen rods.Lincoln's suggested parameters for 3/16 stainless T-joint is 5/32" E3xx-16 rods at 120 amps, travel speed ~9 ipm.Lincoln Excalibur E309-16 lists  60-100 amps for 1/8" rod and 90-140 amps for 5/32" rod.ESAB lists similar recommended amperage parameters.  I don't know what make rod you have that is calling for 140 amps for a 1/8" rod.Welds done in the flat position (1F or 2F)?  E3xx-16 rods are not always rated for vertical (3F) or overhead (4F).  RTFM for 'rated' positions.  The best laid schemes ... Gang oft agley ...
Reply:We ran another test, this time rant the root with 3/32 and turned up the amps to 105, then covered it with a 1/8 cap at 125 amps and this is the results.  It passes and got much better penetration into the A36 Attached ImagesLast edited by MrWeldSoCal; 05-15-2013 at 10:58 AM.