Effects of Heat Treatment on Microstructure and Properties of Ultra-supercritical KT5331ASO Steel
The effects of heat treatment on microstructure and properties of ultra-supercritical KT5331ASO steel (10Cr11Co3W3NiMoVNbNB) were studied. The results show that the microstructure of KT5331ASO steel is tempered lath martensite when quenching at 1050～1150 ℃ and tempering at 660～720 ℃. The tempered lath martensite grows up with the tempering temperature increasing, however the tendency of growing is not obvious. With the increase of tempering temperature, the lath martensite has higher durable intensity because the isolation of carbon compounds causes the strengthened precipitation. KT5331AS0 steel has higher overall mechanical properties when quenching at 1080～1100 ℃ and tempering at 680～700 ℃.