Wrong PWHT Procedure Applied?
Wrong PWHT Procedure Applied?
(OP)
I have a carbon steel valve with flanges welded one and the wrong heat treat procedure applied to it. The heat treat procedure used holds the temperature at 1550-1650 F for 45 minutes then removed and quenched in oil, until cool. The parts are then tempered in 1000 - 1200 f range for 2 hours to obtain hardness of Rc 28-36.
The correct procedure places the components in a furnace at 800 F, and increased to 1100-1200 f for 15 minutes per inch of weld thickness. After reaching 800, it is cooled in still air.
Is there something I can do, or should the part be scrapped.
Thanks!
The correct procedure places the components in a furnace at 800 F, and increased to 1100-1200 f for 15 minutes per inch of weld thickness. After reaching 800, it is cooled in still air.
Is there something I can do, or should the part be scrapped.
Thanks!





RE: Wrong PWHT Procedure Applied?
If the measured hardness is acceptable with the client, I would perform a surface NDT to ensure no cracks and report that the carbon steel valve and flanges were subjected to a normalization with liquid quench and temper heat treatment. The 1000 deg F temper is lower than I would like to see, but this is why I suggested obtaining hardness data to corroborate your assumption.
RE: Wrong PWHT Procedure Applied?