Dissolution of laves phase by re-austenitization and tempering of creep strength enhanced ferritic steel

Abstract

Formation of Laves phase in creep strength enhanced ferritic steel is investigated using re-austenitization and tempering treatment. The as-received material is exposed to 620�C for 4560 h aging, and then� re-austenitizated at 1050�C for 1 h, and followed by tempering at 760�C for different times (2 and 4 h). After re-austenitization and tempering, the dissolution of Laves phase is observed while grain size and microhardness have not changed significantly. A model is suggested to quantify the dissolution of W-containing Laves phase. Thermo-Calc is used to predict driving forces for precipitation of Laves and M23C6 phases. � 2020, � 2020 Institute of Materials, Minerals and Mining.