625 overlay on 8630 yield stress reduction.
625 overlay on 8630 yield stress reduction.
(OP)
We often use a 625 weld overlay on 8630 components that need to comply with API 6a and NACE MR 01-75 and we are finding a serious reduction (10% to 20%) in the yield stress of the underlying material. Does anyone know of a way to recover this whilst maintaining the NACE compliance?





RE: 625 overlay on 8630 yield stress reduction.
RE: 625 overlay on 8630 yield stress reduction.
Weld process is GTAW with hot wire filler, preheat to 150C interpass 150C to 300C postweld heat treat 660C. The 8630 starts off quenched and tempered with a mimimun yield of 85ksi.
RE: 625 overlay on 8630 yield stress reduction.
RE: 625 overlay on 8630 yield stress reduction.
Thanks looks like PWHT might be too hot, the orginal temper was at 660C.