Buttering with Inconel PQR and materials qualified under Section IX

[FluidicTech]

We often butter P1, P4, P5A and P5B base materials when welding them to P8 material to avoid PWHT (of the final joint) of the P8 material. When the design temperature is significantly high, we use Inconel to butter, then heat treat, and then use Inconel filler for the final joint. We currently have processes qualified for buttering with SMAW, heat treating, and completing the joint with GTAW & SMAW. We are looking at qualifying some new procedures that use FCAW or SAW to complete the joint after the buttered material has been heat treated.

Paragraph QW-283 of Section IX deals with buttering. All buttering thicknesses are or will be 3/16" or greater. The QA department believes that we can, under QW-283.4(b), use Inconel plate for the test coupon which matches our Inconel filler, and subsequently qualify all P1-P8, P4-P8, P5A-P8, and P5B-P8 welds at the same time without having to qualify procedures for each of these different base metals.

I interpret paragraph QW-283.4 as stating that if "an essential variable is changed in the portion of the weld to be made after buttering" a new qualification can be made by using inconel plate that matches the filler metal. However, because changing the base metal is an essential variable in the portion of the weld prior to buttering, this is not applicable. Therefore, we would have to qualify a different procedure for each different base metal.

I am not a Section IX expert, and the QA department has more experience here than I do. But, their interpretation doesn't seem quite right to me. Who is right? Please elaborate on the intent of paragraph QW-283.4. Sorry for the length...

 

[metengr]

Your QA department is not interpreting this section correctly. QW-283.4 applies to one of two situations; either a change in an essential variable during an original procedure qualification with buttering or a second organization completes the weld joint after buttering after the first organization qualified the weld procedure with buttering and could not complete the weld joint.

In your case, your QA department is relying on (b) as though the weld was partially completed, and a second organization is now going to qualify the finished weld between P-8 and Inconel. Well, who is going to qualify the buttering of Inconel to P-1, P-4, P-5A as part of this requirement for 283.4 (b)???????????

 

[FluidicTech]

Thanks for your input. Does anyone else have an opinion. Any Section IX welding experts? I would like as much input as possible. Thanks.

 

[metengr]

FluidicTech;
I gave you a detailed response. I don't call myself an expert in anything but if you read my background, it speaks for itself.

 

[GRoberts]

I probably shouldn't answer since you asked for "experts", but here is my 2 cents. I can definately see your and metengr's points. I think your QA dept is not looking at is as changing the base metal but changing the welding process after buttering. However, the "essential variable" thing seems to be a cathc 22 for their philosophy since the welding process is not listed in the essential variables tables (such as QW-254), but instead there is a different table for each process.

 

[weldtek]

Nor do I call myself an expert, but,I have to comment because Metengrs answer is so concise. Why not just pose his question to your QA Dept? They won't have an acceptable answer.