Heat treatment process test of 50CrVA steel tooth chain plate

The microstructure and properties of tooth chain plate 50CrVA steel quenched at isothermal temperature were studied.The results show that,when the isothermal temperature is constant,bainite content of the steel increases as the quenching temperature increasing,and the hardness is almost constant.The optimal process for 50CrVA steel is austenizing at 900 ℃ for 20 min,isothermal quenched at 300 ℃ for 35 min and then tempered at 200 ℃ for 120 min.The steel hardness is 52-53.5 HRC,and fatigue life can be over 1×107 cycles.