Effect Of Heat Treatment On Structure And Mechanical Properties Of Heat-Resistant Steel G-X12CrMoWVNbN10-1-1

In this paper, heat treatment and high temperature mechanical properties of new martensitic heat-resistant steel G-X12CrMoWVNbN10-1-1 were researched in order to prove that this kind of steel can be used for elevated steam parameter thermal generator set, therefor increase generating efficiency and reduce exhaust gas. So it has great benfit to economy and society.In this paper, equilibrium precipitated phases in heat-resistant steel G-X12CrMoWVNbN10-1-1 were studied using software Thermo-Calc for Thermodynamic analysis. And effect of alloy elements on precipitated phases and Heat treatment including quencher and temper on microstructure and properties ware also analyzed. High temperature tensile properties at different high temperature of 550℃, 600℃, 650℃, 700℃were tested and the tensile fractures were scanned. The follow facts were discovered:The equilibrium precipitated phases in cast heat-resistant steel G-X12CrMoWVNbN 10-1-1 areδ-Fe,γ-Fe,α-Fe, MX, M23C6, Laves. The elements in steel affect the austenitic range, and second-phase amount and their precipitating temperature.Comprehensive mechanical properties of steel with wind quenching were better then that with oil quenching, but the difference was not obvious. Tempering temperature significantly affected the mechanical properties of steel G-X12CrMoWVNbN10-1-1. If it's too low, lath martensite can not recover sufficiently. In another hand, if the temperature is too high, martensite transform and become tempered sorbite. The temperature range between 735℃and 775℃is the most suitable tempering temperature.G-X12CrMoWVNbN10-1-1 has great soft-resistant property at high temperature, good stength and plasticity. The tensile fracture mode is ductile fracture at testing temperature. Impurity in steel significantly affected plastic and ductility properties, and affected the strength slightly.