Welding Alloy 625 and its Interpasses

[twoheads]

Looking for some help on this one, when welding Inconel 625 overlay , what would be suitable interpass.I have a feeling I am too high at the moment using pre heat and interpass temeratures based on the substrate material, the weld is becoming discolored, with an almost oxidised look to it.

If the interpass was too high what problems should I expect to see on the surface of the weld.

Thanks in advance again,

 

[metengr]

the weld is becoming discolored, with an almost oxidised look to it.

I presume you are using a solid wire, semi-automatic welding process for the weld overlay. If so, check your shielding set-up and shielding gas mixture. We have welded 625 with preheat as high as 400 deg F, and interpass temperature as high as 700 deg F, with no problems.