Properties of low-alloy high-speed steel at elevated temperature

This paper presents the results of research on the determination of the coefficient of thermal conductivity and hot hardness of cutters made of selected grades of low-alloy high-speed steels, HS 6-5-2 and HS3-1-2. The investigations of hot hardness and yield stress values of HS6-5-2 steel at elevated temperatures have shown that the hot hardness value decreased to 650 – 700 HV (59 – 60 HRC) in the temperature range of 500 – 550 °C. However, the hardness of the samples preheated to the temperature of 500 – 550 °C and measured at room temperature does not change. A decrease of the hot hardness of the steel is correlated with decreasing yield stress at elevated temperature.