A656 Gr80 to 1045

Date 01-07-2008 18:46

We have a project for a customer which requires welding clevis's to a shaft. The clevis's are 656 Gr80 material .500" thick. The shaft is 1045 and 1.375" thick. The entire weldment is approx 25" long and has 4 of these clevis's welded to it. The clevis's slip over the shaft and will be welded " all around". 6mm fillets.
( These will be welded robotically)
I plan to weld these with ER80S-D2 filler and 95/5 Ar/Co2 shield. For manufacturing reasons, I would like to do this avoiding a pre-heat situation if possible.
I will be doing some samples, macro-etching them. I also plan to send these samples to my Met Lab
for analysis, of course looking for cracking.

What is everyone's opinion on validating this process without the aid of the preheat ??

Thanks everyone !

By Bill M

Date 01-07-2008 19:58

My 2 cents worth, & playing devils advocate-

If it is a clevis it sounds like lifting? If it is lifting...what is your potential liability exposure if the weld fails? If there is significant exposure, and the weld fails and the worst happens....an attorney will have a field day providing expert witnesses recommending a welding preheat.. that was evidentally ommitted for "manufacturing" reasons.

Try qualifying the welding procedure without the preheat and see what happens with the tensile and bend tests. I would also recommend some tensile and proof load testing on some completed first article parts.

By 803056

Date 01-08-2008 03:57

Good advice.

Al

By cfrancis (**)

Date 01-08-2008 12:49

Thanks everyone.
I looked at Table 3.2 for the minumum preheat required for 1045 ( Astm A108) and I do not see it in there? What would be my minimum preheat for 1.375" dia. ?