Heat Treatment Process Of Casting-ZG1Cr10MoWVNbN Heat-Resistant Steel Used For USC

ZG1Cr10MoWVNbN heat-resistant steel-the new material of independent intellectual property rights is usually used to fabricate the key parts such as high pressure cylinder, nozzle and main air valve. The research and development of ZG1Cr10MoWVNbN heat-resistant steel is very important to develop heat-resistant steel and power generation technology of Ultra Super Critical because of the energy shortage and environmental pollution.In this paper, effects of quenching and tempering temperature on microstructure and mechanical properties of cast and forged sample were studied, the heat treatment parameters are optimized to provide the heat treatment process parameters to cast instead of forge.OM, SEM and TEM were used to observe and analyze the microstructure and fracture. Some major conclusions were drawn:(1)The cast and forged sample of ZG1Cr10MoWVNbN heat-resistant steel after quenching at1040～1160℃and tempering at730"C could meet the mechanical properties requirements.(2)The quenching temperature has considerable influence on austenite grain size and mechanical properties of ZG1Cr10MoWVNbN heat-resistant steel.With quenching temperature increasing, the austenite grain grew constantly. The rates of austenite grain grew slowly when quenching temperature is lower than1100℃, the rates of austenite grain grew quickly when quenching temperature is higher than1100℃.With quenching temperature increasing, the strength and hardness increased constantly, the impact toughness declined constantly. The strength and hardness increased quickly before1100℃, it became stable after1100℃. The impact toughness lowered quickly between1100～1130℃.On the austenite grain size and mechanical properties sides, it is better to quench at1100℃.(3)The tempering temperature has considerable influence on mechanical properties of ZG1Cr10MoWVNbN heat-resistant steel. The martensite which recovered inadequately has high hardness due to lower tempering temperature, or decompounded and entered two phase region has low hardness due to higher temperature.730℃is the optimal tempering temperature.(4)The optimal heat treatment process parameters are quenching at1100℃, tempering at730℃.