INFLUENCE OF POST WELD HEAT TREATMENT ON THE HAZ IMPACT TOUGHNESS ON P91 STEEL

Appropriate post weld heat treatment is usually obligatory when creep resistant steels are welded for thermal power plant components which operate at elevated temperatures. Influence of different post weld heat treatments on microstructure and impact toughness were studied in this work. Heat treatments were performed at different temperatures (740°C and 760°C) in duration of two hours at different regions of artificially made heat affected zones. The coarse grain (CG HAZ), two different regions of the fine grain (FG1-HAZ and FG2-HAZ) and inter critical (IC HAZ) heat affected zones in comparison with base material were analysed.