Forecast of tendency to long term hot embrittlement of austenitic-ferritic weld metal

The processes of high-temperature ageing and the tendency to hot embrittlement of austenitic-ferritic weld metal have been studied. The experiments have been carried out at electrode welded samples of steel plates 30 mm thick. The metallographic analysis of impact bend tested samples was made. It is found that the hot embrittlement of austenitic-ferritic weld metal at the ageing temperatures from 550 to 750 deg C is connected with the formation of intermetallic phases and is expressed by time dependence characterizing the rate of impact strength decrease, and by the temperature dependence proportional to the beginning of the embrittlement. Numerical values of the coefficients for weld metal under study are found for the dependences obtained