Hey guys, working on a job right now. Parts are a 1.25 chrome base. We are welding a 309ss butter layer and a Stellite 6 overlay. welding looks great on the outside but after machine we are finding small imperfections. Its not cracking but just small little holes, looks like porosity but on a very very small scale. Im running the wire on Pulsed Spray with a 600°F preheat. Ive tried using 2 different gases, 75%AR 25%CO2 and 92%Ar 8%CO2. Anyone have any experience with cobalt based alloys?
Welder chimp
- Welder chimp
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Joined:Sun Mar 18, 2018 1:11 pm
Is the 600 degree preheat a requirement as per the Welding procedure? The little bit of Stellite I’ve done, we were requied to keep it below 500 degrees.
- weldin mike 27
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Weldmonger
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Joined:Fri Apr 01, 2011 10:59 pm
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Location:Australia; Victoria
Be wary of oily residue on the wire. Those special alloys sometimes have machine gunk left on them. A scotch brite pad bulldog clipped over the wire as it goes into the drive rollers can help.
So we dont exactly have a proper welding procedure for this. The 600°preheat is coming from are metallurgist. But i agree with you on keeping it cool. Everything I have read has said to keep the part cool. Suggested 400° interpass temp max. And an update. I finished a part yesterday and kept the interpass temp under 500° and they machine the part today and it was perfectly clean. Thanks for the help guys!!