| 摘要 |
PURPOSE: Steel alloy for a press mold with excellent corrosion resistance and low frictional coefficients and a press mold using the same are provided to prevent a plating layer from breaking and the surface of a steel sheet from having scratches by lowering frictional coefficients between metals. CONSTITUTION: Steel alloy for a press mold consists of C of 0.2~0.5 weight%, Cr of 8.0~12.0 weight%, Cu of 5.0~15.0 weight%, Fe and other inevitable impurities. The surface hardness of the steel alloy is Micro-Vickers hardness of over 450Hv. Alternatively, the surface hardness of the steel alloy is Micro-Vickers hardness of 475~575Hv. The maximum frictional coefficients of the steel alloy are below 0.16 at a temperature of 25°C, load of 7ksi and 100 cycles. At the steel alloy, the phase fraction of martensite is over 50% based on the area rate of microstructure and the rest has austenite phase. |
