提高凸模寿命的途径

一般电机硅钢片冲裁用凸模采用Cr12钢制造，热处理工艺是淬火 低温回火。由于Cr12属莱氏体钢，共晶碳化物虽经锻碎。但仍粗大且有棱角．致使凸模强韧性不足，寿命不高：改用9SiCr钢并采用刃口双液淬火、整体等温淬火热处理．使碳化物均匀圆整．提高了刃口硬度、耐磨性和凸模整体的强韧性，使用寿命显著提高。

Way to Prolonging Life of Punch

The punch used for motor silicon steel punching is usually made of Cr12 steel,and its heat treatment process is quenching and low temperature tempering.The Cr12 steel is a kind of Ledeburite steel.Although eutectic carbides are smashed by forging,they are still coarse with ridgy which lead to toughness insufficient and not enough service life of the tool.While 9SiCr steel is used to replace Cr12 steel and a new process of double-solution quenching for edge and the whole isothermal quenching is adopted,the carbides become even in size and circular,the hardness and wear resistance of the edge,and the strength and toughness of the bulk punch are improved.Its service life is eventually enhanced.