Optimisation of post-weld heat treatment of a 1.25Cr-0.5Mo pressure vesselfor high temperature hydrogen service

The ASME pressure vessel design code permits a range of post-weld heat trea tment temperatures for 1.25Cr-0.5Mo pressure vessels Studies using analytic al transmission electron microscopy, X-ray diffraction, hardness and Charpy toughness testing, were performed on material from a neu; pressure vessel to understand the effects of various heat treatment schedules allowed withi n the code. These techniques have enabled an optimum heat treatment tempera ture and the time to be determined, with a view to minimising the likely su sceptibility of the vessel to temper embrittlement and hydrogen attack, (C) 1999 Elsevier Science Ltd. All rights reserved.