Welding cast Hastelloy C276 2

[bruv]

I need to develop procedures for welding ASTM A494 CW12MW, the cast version of Hastelloy C276. I hope eventually to have procedures and qualifications in SMAW and GTAW, with and without PWHT. We will be welding our own castings.

Would you recommend welding with matching consumables or would Hast C22 type consumables be a better bet?

Thanks

 

[metengr]

bruv;
What is the service application for the castings?

 

[stanweld]

It is assumed that you are repairing castings. If you are solution treating after welding, matching filler metals may be used. Up-alloying is recommended when deposited weld metal is on the corrosion service side and in the as-welded condition.

Be aware that proper deoxydation practices must be employed in the melting process used for Nickel base alloy castings to preclude hot cracking along the grain boundaries in the casting HAZ.

 

[bruv]

@ metengr: Sorry, I don't know the final duty. I will see if I can find out, but we don't always get told this information.

@ stanweld: You are correct, this is for casting repair. This is a large project for us - we are reviewing all melting/casting practices.

 

[metengr]

bruv;
If it were me I would repair the castings using matching filler metal and perform a re-solution treatment. This is your best bet if you do not know the service duty.

 

[MikeMet]

If you are repairing a discontinuity in a casting made of Alloy C276 you should make the weld using matching filler metal. That way the casting should have homogeneous properties (as much as they can be in a casting). As a customer that is what I would expect. Not a casting of one alloy repaired with a filler metal of a different chemistry.

 

[Guest102023]

MikeMet,
In general that is true, but since C22 filler is often specified for C276, it might be acceptable here. The specific application (i.e., corrosive environment) needs to be considered.