Dissimilar Metal T PQR question

[EmilGies]

I would like to weld a P1(2.125”) – P8(1.5”) full pen groove coupon with dissimilar base metal thicknesses for a PQR. My test lab is not sure how to handle this. I cannot seem to find direction per ASME IX. I expect that the lab has to grind/machine the thicker material to the thinner T.
Any insight would be appreciated.

 

[metengr]

Optimize the weld joint groove angle(s) to provide a 3:1 tapered transition within the weld joint between the thick and thin base materials.

 

[gtaw]

Is the thickness of the completed weld equal to the thickness of the thinner member, i.e., the 1 1/2 inch autenitic stainless? If so, qualify the proceure using 1 1/2 plate.

Best regards - Al

 

[metengr]

Agree with gtaw. Review ASME Section IX, Table QW-451.1. You can qualify both base materials using 1 1/2 plate to cover both materials 3/16" up to 8". In the field, you need to use a tapered weld transition as I mentioned above.

 

[EmilGies]

Sorry, perhaps I didn't word the original question properly. I understand the qualification ranges but I am looking for direction in the Code as to what to do with a sample coupon that has two different metal thicknesses. My AI has advised that the lab should machine the thicker to match the thinner. I don't have a problem with that, I was just hoping for some more direction in the Code.
Why? We have some P1G2 material that is 2.125" in house. A lot cheaper and quicker to use that material than to order mat'l special for this qual.
Thank you,
EG

 

[metengr]

I understand the qualification ranges but I am looking for direction in the Code as to what to do with a sample coupon that has two different metal thicknesses.

The Code provides general guidance for coupon geometry, mechanical testing and thickness requirements for weld procedure qualification ranges. As you stated, you can machine the coupon thickness prior to testing to match thickness, it makes no difference.

 

[tab1999]

I agree with Metengr,
The lab has specific criteria which will be based on the thinner of the 2 members. AWS and ASME mention the slopes for finished welds. The coupons have a given thickness of 1 1/2".

My 2 cents worth.

 

[weldtek]

The dissimilarity you are faced with should pose no problems for standard testing per Sec IX. It won't affect the bends if they're done in a guided wrap around jig as shown in QW466.3, and the tensiles and charpy's if req'd, will be machined anyway. Hardness tests, and macro's will be unaffected.