normalizing
normalizing
(OP)
hi guys
i recently purchased 350 tonns of asme sa516 gr70 plate from a european steel mill and the material ha failed charpy inpacts (dismal)we have checked the certs and found the plate was normalized @ 30 min per inch,now from reading your forums i understand that asme says 1 hr per inch,do i have any claim on the mill.
just to give u a background on the testing,we have done pwht testing on coupon plates.
soaking temp-625 c heating rate 50c/hour above 350c
time 495 min cooling rate 50c/hour above 350c,customers requirements are 27j ave,18j min at -48 deg.c.
we are getting 14,13,16,25 etc.
i am now re-normalizing 3 plates to see if this will rectify the problem(is this the right way to go????)
i recently purchased 350 tonns of asme sa516 gr70 plate from a european steel mill and the material ha failed charpy inpacts (dismal)we have checked the certs and found the plate was normalized @ 30 min per inch,now from reading your forums i understand that asme says 1 hr per inch,do i have any claim on the mill.
just to give u a background on the testing,we have done pwht testing on coupon plates.
soaking temp-625 c heating rate 50c/hour above 350c
time 495 min cooling rate 50c/hour above 350c,customers requirements are 27j ave,18j min at -48 deg.c.
we are getting 14,13,16,25 etc.
i am now re-normalizing 3 plates to see if this will rectify the problem(is this the right way to go????)





RE: normalizing
On a positive note, renormalizing may very well achieve the required results.
RE: normalizing
RE: normalizing
RE: normalizing
I don't understand. Normally, one would purchase material in the Normalized condition, and PWHT the test coupons with the longest anticipated cycle at the highest temperature required for the fabricated component. If its 1 hour then PWHT the test coupons for 1 hour, if it requires multiple cycles then PWHT the test coupons accordingly.
There's no need to PWHT the plate before fabrication, just the test coupons. The cost for 1 hour vs 4 hours would be minimal. The mil may have refused the order with the long PWHT cycle because they weren't comfortable with meeting impacts in that condition.