초록 열기/닫기 버튼

HRV40 is used in the engine valves of vehicles. Since an automobile engine operates at a high temperature of 750 °C or more, it is necessary to study the creep behavior of the valve material to ensure safety and reliability. In this paper, the results of the creep tests at 750~800 °C and a stress range of 50~250 MPa, based on ASTM E139 of HRV40 steel, are included. The data were analyzed by using the Monkman-Grant equation that is related to the steady-state creep rate and rupture time, and the modified Monkman-Grant equation, which is also associated with creep deformation. Larson-Miller parameter, one of the TTP (time-temperature parameters), was used in lifetime prediction. Then, verification testing was conducted.