Development and application of a new hot-work die steel for hot stamping

A new hot-work die steel for hot stamping was developed,and used the die for mass production.The produced die showed good performance owing to its high heat conductivity and wear-resistant characteristics.Two different benchmarking hot-work die steels were investigated,and then compared in terms of their impact ductility,temper characteristics,heat conductivity,and thermal stability.The result of the high-temperature friction wear test indicated that oxidative wear was the main mode in high temperature.On the basis of the comparison and test results,the alloying composition of the new hot-work die steel was especially designed.The new die steel showed good performance with good wear-resistant quality,as well as temper hardness and heat conductivity of HRC 50 and 34.3 W/(m · K),respectively.Furthermore,without surface plasma nitriding,the die made of the new steel had no obvious galling with 6 142 strokes.After surface plasma nitriding,the die completed 40 000 strokes with good surface.The die life is expected to exceed 200 000 strokes.