[MW:16466] Effect of Higher temp PWHT but below AC1 for PQR

Dear Friends

 

I have a query

A)

I have qualified the PQR with Suplimentary Essential (Due to Impact test requirement) 

a)The base material is SA516 Gr 70 Thk-40mm

b)Process-SMAW

c)PWHT as per USC56  Actual PWHT cycle followed 600-620C Soaking temp with soaking time of 3hrs and 30min

d) Satisfied all essential variables including PWHT clauses

e)Impact tested at minus 30C

f)All test are satisfactory as per ASME sec IX

 

Now my querry is can I use above  PQR for making WPS for welding 190mm thk SA516 Gr70 material  with PWHT at 650-670C for 3hrs (As it is below transformation Temp AC1)

 

If you say yes then what is the effect of Higher temp PWHT  on mechanical properties of  SA516 Gr70 even though it is below AC1)

 

(As this PQR is not accpted by Client consultant for WPS welding 100thk material having PWHT temp 650-670C)

asThere is possiblity /references of detoriating the UTS at higher temp PWHT  e.g.As per LM parameter PWHT at660 C for 3 hrs is equivalent  to at  620c for 24 hrs )

Regards

 

Hegde P.B.