Qualifying Inconel 625 to Inconel 625

By TonyF Date 12-12-2017 14:31

Hey guys,

I work at an independent O&G company where we often inlay Inconel 625 to 4130 valve bores. We are qualified for this process.

We often receive repair valves which require the machining of the inlay bores by .050" or so and then welding Inconel back over Inconel to get within tolerance. This is the process we need help qualifying.

We know the coupon size/configuration that we used to qualify the first process also the values and ranges qualified. Would the new coupon we send off be the same OD, Thickness, ETC. except machined and then have another Inconel pass welded to it? Or is the "repair" process included within the first WPS as it often requires more than one pass?

Any help would be appreciated.

-Tony

By 803056

Date 12-13-2017 09:38

The initial WPS qualified by testing can be used for the initial weld and any subsequent repair provided no post weld heat treatment is involved. You might also check to see whether CVN testing is or was a requirement.

Since you are welding on the Inconel, additional PWHT may not be required even it was a requirement when the valve seat was initially welded. One would have to know whether the existing overlay is thick enough to ensure the 4130 isn't heated above the transformation temperature.

Details, details, details.

Al

By TonyF Date 12-13-2017 15:57

Al, we require at least 1/8" of overlay on our WPS as well as a PWHT. Worst case for repair we would machine off .050" putting that thickness now at .075". Our max interpass temp used on repairs would be 350F and we would not require a PWHT for that repair. Charpy testing was a requirement. We already have a repair WPS.

So from what I understand our welders would be qualified to do that repair without having to send off another coupon? What about the accompanying paperwork? I apologize for all the questions just kinda got thrown into this.

By 803056

Date 12-13-2017 20:19

Your welders should not have to be requalified.

Al