A516g70 low impacts after welding
A516g70 low impacts after welding
(OP)
We attempted to qualify 3/8" thick 304L to A516g65 welded with E309LT-1. Everything worked fine, but my CVN tests in the 516 base metal were 10, 7, 7 ft-lbs at -20°F. The MTR for that plate shows 140s at -50F, and we had another sample from the same plate tested (unwelded) and got 130s. The 304 (147ft-lb), weld metal (27ft-lb) , and both HAZs (28-35ft-lbs) were acceptable. I can't understand what happened. The lab took another CVN sample of the base from a different location turned 90° thinking we had the coupon grain direction wrong, with similarly poor results. It was not a typo error; they said the specimens showed very brittle fracture appearance.
Preheat: 100F
interpass: 340F
No PWHT.
coupon size: 14"x6"x3/8" each plate, welded on the long seam. ~60° single v-groove.
heat input: ~16-18 kJ/in
Position: 1G
Root weld, hot pass, then backgouge/backweld, then two more layers on the top.
Any ideas would be appreciated. My next thought is to attempt with GMAW-S using ER309L, but I'm somewhat hesitant without understanding what happened here.
Preheat: 100F
interpass: 340F
No PWHT.
coupon size: 14"x6"x3/8" each plate, welded on the long seam. ~60° single v-groove.
heat input: ~16-18 kJ/in
Position: 1G
Root weld, hot pass, then backgouge/backweld, then two more layers on the top.
Any ideas would be appreciated. My next thought is to attempt with GMAW-S using ER309L, but I'm somewhat hesitant without understanding what happened here.





RE: A516g70 low impacts after welding
Get the lab to evaluate the grain size in the base metal HAZ.
RE: A516g70 low impacts after welding
RE: A516g70 low impacts after welding
You claim you tested unaffected base material. Why would your results be any different in unaffected base material away from the base metal HAZ? I think your results are from the base metal HAZ which is coarse grained.
RE: A516g70 low impacts after welding
RE: A516g70 low impacts after welding
RE: A516g70 low impacts after welding
CVNs were 10x7.5 (for my test and on the MTR), but that still doesn't get them up to a reasonable result after conversion.
MTR states normalized, and the second unwelded coupon we tested from that plate got good results.