Characterization of the carbides in the steel X20CrMoV12.1 used in thermal power plants

Abstract

Microstructure of the steel X20CrMoV12.1, used for thermal power plants, after tempering at approximately 500 °C consists of tempered martensite with carbide precipitates. The evolution of the chemical and phase composition of carbide precipitates in X20CrMoV12.1 steel was studied in the as-received state after 56000 h at 470-530 °C under load and in heat-treated state (1-1344 h at 800°C) using transmission electron microscopy (TEM) and electron backscatter diffraction (EBSD) technique. The precipitates found in service-loaded state as well as in heat-treated state were of M 23C6 type. In all samples two morphologically different types of carbides were established. Copyright © 2008 John Wiley & Sons, Ltd.