I have a part that is a nickel alloy casting AMS 5377 and it is RSW to a nickel alloy sheet AMS 5536.  My question is this.  Can I certify my weld procedure utilizing only the AMS 5536 in the thickness for the production parts .050" and .040" respectively. 

D17.2 doesn't separate the alloys for nickel they are all under one group but, paragraph 4.5.2 Procedure Certification Test Reports. For each machine and each combination of relevant material conditions (such as alloy, temper, surface conditions, and thickness combinations), the contractor will determine the effective weld machine settings for test and production parts. The conditions and parameters shall be formally entered on a weld procedure before the test welding.

This requires me to record the alloy.  This is why I have the question.