提高螺母镦六角冲头使用寿命的探讨

Study on Increasing the Service Life of Nut Cold heading Hexagon drift

根据镦六角冲头的实际服役条件，采用低温形变淬火、高温回火工艺代替原锻造后球化退火工艺，缩短了生产周期，降低了成本，且改善了碳化物形状及分布。再经渗铌复合处理后淬火、回火，使冲头表面形成单一的碳化铌表层，从而提高了耐磨性，使冲头的使用寿命提高６～７倍。

On the basis of failure analysis of nut cold heading hexagon drift and the characteristic of Cr12 steel,the low temperature thermomechanical treatment and high temperature tempering was employed instead of the spheroidizing.The drift was then niobiumized and quenched and tempered at low temperature.The surface hardness of the combined treated drift and its wear resistant were improved considerably.The service life of the drift could be prolonged to 6 to 7 times than that of coventional treated one.