Qualification of wps as per aws d1.1

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HelloI want to qualify  a WPS as per AWS D1.1.  I am using SMAW process and E7018 electrode.The two materials to be welded have mechanical properties as followsMaterial A -  Yield strength  min 310 Mpa and Tensile Strength min 450 MpaMaterial B -  Yield strength min 350  and and Tensile Strength min 490 MpaAt the moment, stock of material A is not available. Can i qualify the procedure with' Material B' ? I am going to prepare test coupon with butt weld having base metal as material B. Test coupon will not have base meal 'Material A' . Question is1) If the process gets qualified with 'Material B', then can it be used to perform production weld between' Material A' and 'Material B'. My logic is, if procedure gets qualified for higher strength of material then it will definitely work for lower strength of material.2) Does AWS D 1.1 allows it. Regards,Santosh
Reply:Santosh,You're vague about what the materials "A" and "B" are, so my advice isn't real specific.  Check your copy of AWS B2.1 code for the section covering material groupings.  I believe, you will need to qualify with the exact materials in your situation.  This link might also help direct you to the correct area of the code to review.http://www.wpsamerica.com/members/gu...1%20Guides.pdfYou might also look at the pre-qualified welding procedure for SMAW as you may find some guidance there as well.  I noticed that the webpage title mentions these procedures cover materials from group 1 or group2. http://pubs.aws.org/p/350/b21-1-0011...s-with-backingorhttp://pubs.aws.org/p/67/b21-1-01619...pwht-conditionAssuming you're going to use one of these prequalified WPSs, there might be some guideance in them on joining different materials.  My intuition leads me to think that you're going to need the right materials and to qualify your own welding procedure.  But that's a guess...Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:A DABThanks for your reply.I will clarify my requirement in detail. I cannot use pre qualified wps because both the materials mentioned above are not listed in AWS D1.1 code. Thats the reason I am going for qualification of procedure.As mentioned in my query both the materials are carbon steel and have some difference in mechanical properties.Since material is not listed in AWS code i cannot do the grouping as well.Material A - Yield strength min 310 Mpa and Tensile Strength min 450 Mpa - This material may fall in Group I (Grouping is just approximation)Material B - Yield strength min 350 and and Tensile Strength min 490 Mpa  - This material may fall in Group II (Grouping is just approximation)So my question is if I prepare PQR with 'Material B' and if all test results are acceptable then can I perform Production weld between 'Material A' and 'Material B' ? Is it allowed as per AWS D1.1 or I will have to prepare test coupon of 'Material A' and 'Material B'.?
Reply:I believe the short answer to your question is that you should prepare a test coupon with Material A and Material B; particularly in light of the fact that neither material fits the material groups defined in AWS code.There is a forum on the AWS website where numerous experts with the AWS welding codes post on a frequent basis.  I'd suggest posting your question there for a definitive answer.https://app.aws.org/forum/Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:Since they aren't pre-qualified materials in the D1.1 you will have to weld A to B and follow proper inspection methods. I can give you the exact clause tomorrow but the code book is currently at my shop. I just had this come up recently. You should also make double sure that the plates are the correct size and you follow proper inspection methods. Some of the plate sizes, shapes, type and number of bend specimens, change with materials that aren't pre-qualified and they don't always use the standard root and face bend tests.Last edited by burns; 03-24-2015 at 10:25 PM.