2" Plate 709 to 4" Hub 668, SAW L61 EM12, Pre-heat 400 to 600 Degrees, Weld complete, UT rejected .25" in to hub and .25" down 80% of weld. Is this post weld heat problem?
Your UT operator should have been able to tell you the problem but it sounds like you have a multipass weldment and it appears to be a LOF (lack of fusion) between two of the passes or between one of the passes and the weld joint wall.
It could also be a slag inclusion if the operator has poor bead shape and rolled one of the passes over an area that would not allow the slag to excape.
R. Johnson, Thanks for the reply, we air arced down and have found the defect it was located .25" deeper than what the ut hand had stated. It appears to be cracking. I have wittnessed the welding and the beads are laying in nice and flat. The defeact is located in the hub .600",.600" out side of the weld joint in the aparent metal (668).
By -
Date 07-29-2001 20:38
Your description is a bit too sketchy for me to understand. Are the 709 and 668 ASTM material designations?
Weld cracking can have so many potential causes that I do not believe anybody (certainly not myself) can hazard an educated guess. Can you re-state the problem with as much detail as possible please. Possibly then some of us will have a better chance of giving you a good answer.
Regards
Niekie
Todd
Maybe the reason for the cracking, is sometimes the width(oscillation)
is too great! Sometimes when this happens, as it cools it will crack out
on you, so if you are having problems with cracking, maybe check and
make sure they are welding per procedure, and check on the width ratio.
Dale
Thank you all for your replys. We have determind that the cracking problem was caused by not heating up the intire hub (A668) to 400 degrees and maintaining this temperature till weld was complete. We welded around the clock. Also the air supply to our flux hopper was contaminated with oil and water. We installed a in-line filter. At this time we have welded two hubs with no defects detected by UT. All said,
we were not following the procedure! Thanks again for your help..Todd
