METHOD FOR POST-WELD HEAT TREATMENT OF WELDED COMPONENTS MADE OF GAMMA PRIME STRENGTHENED SUPERALLOYS

摘要

The invention relates to a method of post-weld heat treatment of a without a filler material electron beam or laser welded high strength component made of a gamma prime (.gamma.') strengthened superalloy based on Ni or Co or Fe or combinations thereof. The method consists of the following steps a) providing the welded component, then b) heating the welded component by applying a rapid heating-up rate in the range of about 20 to 40°C/min during the entire temperature range from RT up to a temperature T1 of at least 1000°C, then c) holding the welded component at T1 and then heating the component by applying a slow heating-up rate of about 5°C/min to a final temperature T f, then d) holding the welded component at T f for a time t f, wherein isothermal dwell time t f is sufficient for at least partially dissolving the gamma prime phase in the weld and also in the base material surrounding the weld; then e) cooling the component with a cooling rate of about 20°C/min and f) finally optionally applying a precipitation hardening treatment according to the known state of the art