分析了气门顶杆热挤压工艺及模具失效形式 ,电镜观察显示犁削磨损和热疲劳龟裂形成剥落坑是模具失效的主要原因。为此分别采用高速钢、基体钢和钢结硬质合金作为凹模镶块材料进行生产试验 ,结果证明钢结硬质合金镶块模具的使用寿命明显高于其它模具钢 ,能满足实际生产要求 ,但高温润滑仍是亟待解决的问题。 The hot extruding process and mold failure mode of the valve lifter were analyzed. Electron microscopy observation showed that the main cause of the mold failure was plowing abrasion and thermal fatigue cracking. For this reason, the high-speed steel, the base steel and the cemented carbide are respectively used as the die-insert materials for the production test. The results show that the service life of the steel-bonded cemented carbide die set is obviously higher than that of other die steel and can meet the actual production requirements , But high temperature lubrication is still an urgent problem to be solved.