HAZ cracks during bend test (MAGp)?

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Is there anyone know well about pulsed spray transfer arc welding technique(MAGp) on low temperature steel, low alloy steel or heat resistant steel?by using the 80+20 mixed gas with no spatter.Now the problem is a little cracks (or folds)come out after bend test in the HAZ. What caused this?        (Φ1.2mm, vertical up welding)        BTW, it's excellent for other test data. Just call me Robin
Reply:Possibly too much CO2 in the gas mix?   Spray is usually done with less than 15% CO2, or with 2% oxygen instead of CO2.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:The cracks/tears are in the HAZ on the parent material and not in the weld filler/bead?I'd guess improper pre/post heat leading to increased hardness and loss of ductility/elongation in the HAZ.And as DesertRider33 mentioned, usually spray is done with 15% or less CO2 in the gas mix, or a 98-2 argon-oxygen mix.  The best laid schemes ... Gang oft agley ...
Reply:How about posting pics of the bend specimens. Hard to go off of a description"Religion is regarded by the common people as true, by the wise as false, and by the rulers as useful." -- Seneca the Younger
Reply:Through the test procedures,I think 20%CO2 is OK, whether considered the efficiency or the spatter. maybe next time I will upload the pic. Is there any chance for low heat input or welding skills?  I mean it seemed didn't fusion well.Just call me Robin
Reply:any chance a slight breeze/fan/ac/heater is blowing protective gass away?
Reply:are your grind marks transverse to the weld?only thing worse than an ugly woman is an ugly weld
Reply:Whats the criteria for failure?
Reply:true spray transfer requires 85% Argon
Reply:True HAZ cracks are in the base metal.  To help diagnose your problem, we need more specifics on the base metal alloy.  What is the grade of material?  Please give the closest western equivalent, if this is an alloy spec from China.If forced to guess, I'd speculate that there is a problem with pre-heat, interpass temperature, or post-weld heat treatment.  But without more data on the base metal, I can't give you a better answer. Originally Posted by xixiubinIs there anyone know well about pulsed spray transfer arc welding technique(MAGp) on low temperature steel, low alloy steel or heat resistant steel?by using the 80+20 mixed gas with no spatter.Now the problem is a little cracks (or folds)come out after bend test in the HAZ. What caused this?        (Φ1.2mm, vertical up welding)        BTW, it's excellent for other test data.
Reply:Originally Posted by jamztrue spray transfer requires 85% Argon
Reply:D1.5 (at least the one im looking at) doesnt say 80% min. for spray, it just says anything less than 80% argon is considered to be short circuiting. while there is a prohibition of GMAW-S without written consent of the engineer, globular transfer isnt prohibited. will check out the newest edition tomorrow at work. the min. argon everywhere i have read has been 90%.only thing worse than an ugly woman is an ugly weld
Reply:Feel free to limit yourself."Religion is regarded by the common people as true, by the wise as false, and by the rulers as useful." -- Seneca the Younger
Reply:If you are doing a bend test with HSLA you might check to see if it is possible to do.  Often the ductility of these alloys is limited and so a bend test is not a fair test.   Failure in the HAZ means to me that there is nothing wrong with the welding bead.  Something is wrong with pre or post heats, or as I mentioned you are using the wrong test for that alloy.