impact results - UHT material´s welding 1

[FernandoL]

Dear colleagues,

I hope this message finds all you well

Project: ASME VIII- Pressure vessel - material ASME SA517 Gr B. Thickness 9,5 mm.

I have to qualify a WPS for welding ASME SA517 - B with impact requirements at -40 C,

Also is required PWHT, and my first results of impact test @-40C of test plate were very low. (lateral expansion less than 0,2mm and energy less than 20J)

The declared Values of certificate of consumable is 75J @ -73C !!!

Can the presence of PWHT changes so much the values of impact? (certificate´s value is "as welded" and my results is "after PWHT".

Any help will be very useful.

Thanks a lot,

Fernando Lescovar Neto

 

[metengr]

Most certainly PWHT can effect impact behavior of weldments. Exposure to elevated temperature from PWHT can result in secondary hardening for some alloys, thus lowering the impact values from as-welded values.