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

摘要

The ASME pressure vessel design code permits a range of post-weld heat treatment temperatures for 1.25Cr-0.5Mo pressure vessels. Studies using analytical transmission electron microscopy, X-ray diffraction, hardness and Charpy toughness testing,were performed on material from a new pressure vessel to understand the effects of various heat treatment schedules allowed within the code. These techniques have enabled an optimum heat treatment temperature and the time to he determined, with a view tominimising the likely susceptibility of the vessel to temper embrittlement and hydrogen attack.