Hardness testing on existing PQR

[shamrock138]

Hello All,

I am currently on a project that the customer wants hardness testing done on existing PQR's. I have duplicated one of the original test coupons for a PQR, but I am having a hard time finding SA-285 Gr. C 3/8" thick for the second coupon, which was the original material and thickness used for approval. Does the material and thickness have to be identical to the original PQR or can I use a material with equal or greater properties?

Any help would be greatly appreciated.

 

[metengr]

shamrock138;
The material should be the same specification (including heat treatment) if you intend to revise the existing PQR's to add hardness testing values. Why are you even doing this? Do you have a min/max hardness range that is acceptable for the application?

 

[ARENAS3]

Since this is your customer's requirement, it is he that you have to satisfy. I have found that many of our customers actually specify that they want the hardness testing done on base material that will be used in production. Since you are having trouble finding SA-285 gr C (not surprising) you probably are not using it for production. Offer to make the supplementary PQR on what you will use for the production piece.
Just my $0.02.

 

[metengr]

I still question the reason for hardness testing before I would do anything else in this situation. Most weld procedures can be qualified using a generic P-No material that may or may not reflect production material.

Unless, impact testing is required or temper bead procedures are being qualified or there is a specific requirement for maximum hardness to avoid HAC, as in petrochemical applications, hardness testing should be performed on material that is of the same P-No and Group No to simulate production welds.

 

[shamrock138]

metengr,

Thank you for your reply. The request was in the customers specifications. It reads, "As a minimum all PQR's for P1-P6 materials will include hardness readings of the weld deposits in, or converted to, BHN or HVN."

 

[metengr]

With or w/o PWHT?

 

[shamrock138]

That is a good idea ARENAS3. I will have to check with the customer, but using production material sounds more logical.

 

[shamrock138]

There would be no PWHT.

 

[vesselfab]

It's getting more and more prevalent to have them ask for hardness on a pqr...regardless of anything or how old the pqr is.

any new ones we do now i have prepared in both pwht and non-pwht condition, have all the mechanical's done, and then have charpy's done and hardness done.

I have even seen it in specs where the customer wants to send an inspector to witness each welder qualify to the wps.
when I explain that they are already qualified and present the logs, and then tell them how much it will cost to requalify 20 welders on 10 procedures each and that that amount will be billed to his project and will delay things 4-6 weeks..they usually back off that requirement.

 

[JoeTank]

One source of material may be the vessel itself. Are any shhell nozzles being installed that may result in a disc of shell material being available for testing.

Since the hardness of the weld material is to be tested, I think the issue of having the exact grade of base material becomes less critical, since the deposited weld metal is a brew of both base metal and the filler metal.

Joe Tank

 

[stanweld]

shamrock138,
Most Owners will permit you to weld a coupon using the base metal specifications used in production and perform hardness traverses. I assume the Owner wishes to be in basic compliance with API 582 and has stress corrosion cracking service issues. Ask the Owner for clarification.

 

[shamrock138]

vesselfab: I have tried to back them off of the requirement with a large price adder, but they accepted the price with no hesitation.

JoeTank: I am waiting for a response from the customer for use of production material. I agree with your statement as well.

stanweld: In the customers spec., there is mention of API 582.

This is my first posting and I did not expect such helpful advice. Thank you all who have replied.

 

[weldtek]

shamrock,
You're not alone, I've got a job where I have to test all procedures on actual base metal and on the plate with the highest CE.