Characterisation of the Micro- and Nanoscale Structure of New Creep-Resistant Steels for Use in Advanced USC Steam Power Plants

Abstract

The microstructure in the as received condition and after long-term creep exposure (up to about 57000 h at 600 and 650°C of the martensitic 9–12% chromium steels (P92, P91, E911, CB6) developed for advanced ultra supercritical coal-fired power plants has been investigated. Using analytical TEM statistical quantitative analyses were undertaken to determine the micro- and nanoscale structure parameters (dislocation density within the subgrains, the width of the martensite laths/subgrains and the particles parameters). Results of the TEM analyses reveal significant influence of a microstructure after initial heat treatment on the creep strength.