looking at the time temperature parameters Larsen-Miller vs Hollomon-Jaffe they both appear to be different arrangements of the same equation? is this correct?
LM = T (log tr + C)
HJ = T (C + log (t))
The recommended values of constant C range from 20-22.
For tempering some have used C = 18...
If you have a WPS and a PQR for P8.1 to P8.1 you can weld any P8.1 material to any other P8.1 material as long as your WPS allows, (i.e. may be limited by thickness)
I checked ASME II part D it has P8.1 materials available in both 316 and 304.
You may have a WPS and a PQR but you also nee to...
fabricator joined a P1-1 to P5a-1 and completed PWHT to 1250F, B31.1 requires 1300+ for P5a material. ANI approved 1250F at 90 minutes soak, ramp was good.
I would like to confirm that joint is stress relieved can I use harness to confirm ?
Is there a reference of what to expect what hardness...
If you are replacing an existing component, or repairing existing piping you may be able to get away with an inservice test with AI approval, that is system pressure. There are also other NDE options in lieu of hydrotest.
If you are procuring a new component have it tested off-site then at site...
ANSI B1.1-1982 is the version I have at my desk in Appendix B there are formulas for thread tensile stress area and thread shear area for all UNC/UNF sizes listed.
Caution when using shear allowable stress B31.1-2001 102.3.1(B) only allows 80% allowable in shear.