Needing Other's Opinion of QW-216.4

[triger33]

I want to qualify a WPS per section IX as a hard-facing weld metal overlay, using 410 as the weld metal overlay to P5A base metal. QW-216.4 If a weld deposit is to be used under a hard-facing weld metal overlay, a base metal with an assigned P-number and chemical analysis nominally matching the weld deposit chemical analysis may be subsitituted to qualify the PQR. Can someone please give me there interpretation of this paragraph.

 

[metengr]

ertorpey;
Yes. “If a weld deposit is to be used.....”

The weld deposit that is being referred to above is a lower strength high ductility weld deposit (aka butter layer) that is sandwiched between the hardface weld deposit and the substrate. The use of a butter layer is common and necessary to avoid cracking.

What you can do is qualify the hardface (410) on top of base metal that is nominally close to the chemical composition of the butter layer weld deposit. So lets presume (as an exmaple) you use Inconel 82 or 182 as a butter layer, you can select a base metal that matches this filler metal for the WPS qualification. You will still need a PQR for the Inconel weld deposit to P-No 5A for the WPS.

 

[triger33]

Thank you for your replay. So what you are saying, If I qualify a hard-facing weld metal overlay using a butter layer I will need to qualify two PQR's to support my WPS?
(as in your example)One PQR for Inconel 82 to P5A substrate, and one PQR for 410 to a base metal that is nominally close to chemical composition of the Inconel 82.

Or if I already have a PQR for Inconel 82 to P5A base metal, I only need to apply 410 to a bese metal that is nominally close to the chemical composotion of the Inconel 82 and have the coupon tested per requirements of section IX
for hard-facing weld metal overlay to qualify the WPS.

 

[DVWE]

Would it not make sense to qualify as it is done in production? If you look at the requirements in QW-453 to qualify a hardfacing procedure, you have to do a PT test, a hardness test, and a transverse section (and chemistry when required). Why not just do that as opposed to two separate procedures?

 

[metengr]

Or if I already have a PQR for Inconel 82 to P5A base metal, I only need to apply 410 to a bese metal that is nominally close to the chemical composotion of the Inconel 82 and have the coupon tested per requirements of section IX
for hard-facing weld metal overlay to qualify the WPS.

Yes, correct.

Normally, the butter layer that is deposited is going to be a non-hardening austenitic weld composition, so any Ni-base or even 309 stainless can be used. Most organizations usually have a standard P-No 8 to P-No 5A PQR handy so for HFO, all one needs to do is qualify the 410 HFO on P-No 8 base material.

 

[triger33]

Gentleman thank you for your input and sharing your knowledge. My direction and decision has become much easier.