Embrittlement of ferritic-austenitic steels in the process of aging at high temperatures

1. Prolonged aging of quenched steels 08Kh18G8N2T and 08Kh22N6T induces embrittlement at temperatures below 400°. 2. Embrittlement of steels 08Kh18G8N2T and 08Kh22N6T is of the 475° type and is not associated with changes in the microstructure or redistribution of chromium and other alloying elements between ferrite and austenite, but depends on changes in the substructure of ferrite. 3. There is a correlation between the microhardness of ferrite and the fracture toughness of steels after quenching+aging: When the microhardness of ferrite rises to H 170 the fracture toughness drops to <0.1 MJ/m2.