【摘要】 分析了气门顶杆热挤压工艺及模具失效形式 ,尝试用钢结硬质合金取代原模具材料 ,现场试验表明 ,钢结硬质合金模具的使用寿命为原模具的 1 0倍左右。电镜观察显示热疲劳是硬质合金热挤压模具失效的主要原因。更多还原

【Abstract】 The failure of the hot extrusion die of the valve stem is analyzed and a steel hard alloy is adopted on trial as a substitute of the die material. The field experiment indicates that the steel hard alloy used as hot extrusion die material has a wide application foreground, the life of the steel hard alloy die is about 10 times of that of the predecessor die. The SEM observation shows that thermal fatigue is the major cause of the failure of the steel hard alloy die.更多还原