Stresses in GTAW

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Hey all,I was just cleaning up some bits for next weld and noticed these “lines” on the back side of the weld. I’m guessing they are stresses created by the weld?3mm mild steel plate and bracket. Fillet weld both sides. ~135 amps

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Reply:

Originally Posted by husq2100

I’m guessing they are stresses created by the weld?
Reply:I often get involved in adding brackets on material hopper, and tanks. The tanks are usually between 14ga, and 18ga stainless steel, but some carbon, and the brackets between 14ga., and 3/32". Most times I will get instructions/marked up drawing from an engineer with fillet size, location, and length of welds. Brackets that are used for shakers/vibrators are almost never fully welded (can't remember ever getting one, but I'm sure there are exceptions, consult your engineer, your mileage may vary.) . They usually specify not to weld ends , and corners. I guess this is part of the reason, although I've done similar welds, I've never noticed ripples in the steel like that . Is the Plate flat , or did it warp ? Can you feel the ripples, or is it an optical illusion( it looks worse than it appears) ? Oh, BTW nice welding. CheersAirco 250 ac/dc Heliwelder Square waveMiller Synchrowave 180 sdMiller Econo Twin HFLincoln 210 MPDayton 225 ac/dcVictor torchesSnap-On YA-212Lotos Cut60D
Reply:

Originally Posted by albrightree

I often get involved in adding brackets on material hopper, and tanks. The tanks are usually between 14ga, and 18ga stainless steel, but some carbon, and the brackets between 14ga., and 3/32". Most times I will get instructions/marked up drawing from an engineer with fillet size, location, and length of welds. Brackets that are used for shakers/vibrators are almost never fully welded (can't remember ever getting one, but I'm sure there are exceptions, consult your engineer, your mileage may vary.) . They usually specify not to weld ends , and corners. I guess this is part of the reason, although I've done similar welds, I've never noticed ripples in the steel like that . Is the Plate flat , or did it warp ? Can you feel the ripples, or is it an optical illusion( it looks worse than it appears) ? Oh, BTW nice welding. Cheers
Reply:

Originally Posted by albrightree

I often get involved in adding brackets on material hopper, and tanks. The tanks are usually between 14ga, and 18ga stainless steel, but some carbon, and the brackets between 14ga., and 3/32". Most times I will get instructions/marked up drawing from an engineer with fillet size, location, and length of welds. Brackets that are used for shakers/vibrators are almost never fully welded (can't remember ever getting one, but I'm sure there are exceptions, consult your engineer, your mileage may vary.) . They usually specify not to weld ends , and corners. I guess this is part of the reason, although I've done similar welds, I've never noticed ripples in the steel like that . Is the Plate flat , or did it warp ? Can you feel the ripples, or is it an optical illusion( it looks worse than it appears) ? Oh, BTW nice welding. Cheers
Reply:This is typically for dump truck application, notice the safety chain. :  http://www.vibco.com/docs/quick-ref-...nce-manual.pdf     https://www.weldingweb.com/images/smilies/eek.gifThis is for stationary equipment.  :       http://www.vibco.com/docs/quick-ref-...nce-manual.pdfAirco 250 ac/dc Heliwelder Square waveMiller Synchrowave 180 sdMiller Econo Twin HFLincoln 210 MPDayton 225 ac/dcVictor torchesSnap-On YA-212Lotos Cut60D
Reply:Looks like some serious vibration going on.It seemed like a good idea at the time!
Reply:Not sure what caused the cracking in your piece, but depending on materials and design, many fabrications require a post weld heat treatment:https://www.metalworkmasters.com/pro...eat-treatment/
Reply:

Originally Posted by albrightree

..... Is the Plate flat , or did it warp ? Can you feel the ripples, or is it an optical illusion( it looks worse than it appears) ? Oh, BTW nice welding. Cheers
Reply:Here are some more pictures This is the other side mounting plate and it’s bracket. Same material, thicknesses and settings. Not near the number or definition of “swirls”, but still a few....Sorry about rotation, this website does that and I’m not sure how to correct it.

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Reply:Some of the 100x50x3 RHS cross member “tube”  (4x2x1/8) and the folded 3mm plate I laminated it with for impact resistance. Some very faint lines radiating outward around the cutouts.

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Reply:The welds before I sprayed them with lanotec (penetrant /corrosion inhibitor). It helps save prep for next stage as surface rust starts within hours and is visible next day.

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Reply:

Originally Posted by albrightree

....Brackets that are used for shakers/vibrators are almost never fully welded (can't remember ever getting one, but I'm sure there are exceptions, consult your engineer, your mileage may vary.) . They usually specify not to weld ends , and corners. I guess this is part of the reason...... Cheers
Reply:Is there some type of coating on the steel? It would be interesting to know how deep the cracks go. If parts are too restrained (held in place to try and control distortion) could do the opposite and create stress in the welds, especially if higher heat/amps are used.
Reply:I will have to say I have never seen that before. Do you have MTRs on the material?Weld like a "WELDOR", not a wel-"DERR"

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Reply:Good morning,After reading the thread several times, it’s not clear if there are physical cracks or just indications of cracks from the backside.  The thing that jumps to mind are brittle coating materials for stress analysis.   Long shot here:  has the oxide layer formed an equivalent brittle coating material during the weld and once cooled, cracked accordingly?   If this was a brittle coating test, the crack lines would make perfect sense from the point of thermal stresses. That is, they would be perpendicular to the tensile stress.  Short note on brittle coating.  https://www.oreilly.com/library/view...apter010.xhtmlRegards
Reply:Yes I have seen this,, I Googled it, 91% of the time, it is due to applying filler metal left handed,, because of the swirl direction of the gas coming out of the torch.Also, people gotta learn that left handed adjustable wrenches can only be used in Australia,, THAT is why we do not have them in the tool room,,,



Reply:What about metric crescent wrenches?
Reply:

Originally Posted by Welder Dave

Is there some type of coating on the steel? It would be interesting to know how deep the cracks go. If parts are too restrained (held in place to try and control distortion) could do the opposite and create stress in the welds, especially if higher heat/amps are used.
Reply:

Originally Posted by shovelon

I will have to say I have never seen that before. Do you have MTRs on the material?