汽车转向节热锻模的失效研究

A Study of Failure Form of the Hot Forging Die for Autotruck Steering Axles

研究了5Cr2NiMoVSi钢制造汽车转向节热锻模具的失效形式。结果表明:模具在冷热交变应力与摩擦剪切力的作用下,其型腔表面产生了众多的热疲劳网纹及凸凹不平的线状沟槽,尤其在模具分料处的桥部,由于红热毛坯的激烈流动,使之出现了严重的磨损塌陷,导致毛坯金属不能充满型腔而失效。文中还分析了模具材质中的非金属夹杂物对热疲劳裂纹扩展的影响;模具表面变质层的组织、特性及其对模具寿命的反作用。

This paper has studied a failure form of the forging die of autotruck steering axle. This forging die is made of 5Cr2NiMoVSi steel. The results show thlt on the one hand, more surface checking and the unlevelling gulleys has been produced by cold or hot stresses and shearing stress on the die cavity. On the other hand, the serious wear down has been prduced by a sharp flow of blank metals in bridge area. Therefore the metals con't fill the die cavity, the forging die con't work completely. In this paper the effect of non-metallic inclusions in steel of the forging die on growth of surface checking was probed. And the reaction of suface lumellar changed on the life of the forging die was observed. The structure and behavior of surface modified lamella and its effect on the life of the forging dies was discussed.