Impact test after SPWHT 1

[sk90]

Dear Members
In one of the pressure vessel,designed as per ASME SEC VIII
the raw material SA 516 gr 70 ( 3 in thk)which is being used from existing stock,is impact tested at minus 30 deg F and the impact values are satisfactory ( 100J)
The vessel is to be post weld heat treated. As per CLIENT specification requirements ,the raw material is to be impact tested at minus 50 deg F after Simulated PWHT .

I would like to know that if after simulated PWHT will their will be any change in impact properties ?For Ex If the raw material say is impact tested at minus 50 F, what will be the effect of SPWHT on impact properties ?


Secondly will the no of cycles of PWHT ( second/third)will have any effect on impact properties?

Any useful links on this subject will be appreciated

Thanks in advance
Sridhar

 

[metengr]

sk90;
PWHT time and temperature parameters along with cycles will have an adverse affect on impact properties of SA 516 Grade 70 steel.

I have included a web site that specifically addresses the isse of PWHT effects;

http://www.intlsteel.com/content/products/prod_plate_lit.aspx

If you need specific technical information regarding PWHT cycles, I would contact the International Steel Group directly.

As an option, you could perform your own simulated PWHT cycles and determine the effects on Chapry impact properties if you have enough raw material. Charpy impact testing is relatively inexpensive and can be performed by a reputable metallurgical lab.

Performing your own tests will provide actual data for the client to review.