ANY SUGGESTIONS ON WELDING 316 1/2" STEM TO STELLITE HEAD.
HAVING PROBLEMS WITH EITHER WELD OR STELLITE HEAD CRACKING.
USED 308L AND 309L, HAVE PREHEATED AT SEVERAL TEMPS WITH NO
LUCK. STEM IS PUT IN A 1/2" HOLE ABOUT 3/4 DEEP. STELLITE IS #12
CAST ABOUT 1 1/2" ROUND. We have pre-heated at 200,300,600,1000
degrees. We have tried washing from the stellite to the 316L stem and from the stem to the stellite head. We have had various problems, the weld cracks radialy in the middle of the weld, sometimes the weld is good and the stellite face cracks from the toe of the weld out. We have recently went from gapping the bottom with a 1/16 space to using a thin piece of heat treat insulation aprox 1/16.
Have welded stellite to stellite, and even that could be problamatic at times. Cracking was common. I've never welded it to the SS you noted, provide a little more info and maybe some one else could help you. Info such as process, filler metal, etc. would help your ping.
We don't seem to have cracking problems, but we weld stillite bushings to HY80 and use 100F max interpass, & use ERNiCrMo-3 filler metal with GTAW process.
How do you hold the interpass temp to only 100F? Seems too cold, even for TIG.
Curious,
John Wright
High preheat is a must, I would suggest , and slow cooling after welding also. Stainless steel filler metals are no good as dilution with the melted stellite will add carbon and cobalt to the weld metal and thus make it crack sensitive. I would suggest using Inconel 82. The thermal expansion coefficent is between that of Stellite and 316ss and the 82 material is very ductile, so it will "give" a little as it cools, helping prevent cracks. 82 is also metallurgically compatable with cobalt alloys and stainless.
Let us know how you make out.
Regards.
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