Embrittlement of a superduplex stainless steel in the range of 550-700 °C

In order to investigate this question, heat treatments in the range of 550-700 °C, with different exposure times and cooling rates, have been made on a superduplex stainless steel type EN 1.4507. The evolution of mechanical properties has been followed by means of hardness measurements, impact and fracture toughness tests, whereas microstructural changes have been identified by using optical and transmission electron microscopy analysis. A correlation between the degree of embrittlement and the different types of precipitates has been established.