一种热反挤压时坯料的定位方式

A positioning method during hot backward extrusion

为解决热反挤压时坯料定位问题,采用外置定位钳的方式,将直径小于凹模内径的坯料放置在凹模中心,使反挤压过程中凸模的、坯料、凹模的中心在同一轴线上,保证金属均匀受力。运用Deform-3D软件,针对直径小于凹模内径时的坯料反挤压过程进行有限元数值模拟,分析了金属成形过程中的成形效果及应力分布,结果表明:模拟与工艺试验结果基本吻合,在热反挤压过程中,成形效果良好,金属等效应力分布均匀。经工艺试验验证,该定位方式操作简单,工件氧化皮较少,表面精度较高,适用于各类直径小于凹模内径的坯料定位,符合生产要求。

In order to solve the location problem of hot backward extrusion billet, the external positioning clamp mode was adopted which took the billet whose diameter is less than the inside diameter of die into the center of die, so that the punch, blank, center of die stayed in the same axis during hot backward extrusion process to ensure the stress uniformity of metal. Using Deform -3D software, aiming at the simulation of blank whose diameter is smaller than the inside diameter of die during backward extrusion process, the forming effect and distribution of stress in the process of metal forming were analyzed and verified by process test. The result shows that the simulation and experimental results are basically consistent. In hot backward extrusion process, the forming effect is good, and the metal equivalent stress distribution is uniform. Through process test, the method has the advantages of simple operations, less oxide coating, high precision, and it＇s applicable to all kinds of billet locations whose diameter is less than the inside diameter of die, which meets production requirements.