(燕山大学 机械工程学院， 秦皇岛 066004)
摘 要: 机械扩径是制造各种管筒形零件的有效方法之一。 研究机械扩径技术，首先需要建立管坯在扩径过程中可以扩圆的整体屈服条件和可能扩裂的局部破坏条件。根据管坯的基本变形规律和主要特征，提出了在机械扩径过程中，管坯变形可以分为整圆和扩径两个阶段的概念。 通过对这两个变形阶段的应力分析，建立了管筒形零件机械扩径时的整体屈服和局部破坏条件，即机械扩径成形条件。
关键字: 机械扩径；应力分析；成形条件；管筒形件
（College of Mechanical Engineering,
Yanshan University, Qinhuangdao 066004, China）
Abstract:Expanding is one of the effective methods for producing cylindrical parts. It is a key subject in the basal research on expanding technology to set up a reasonable technical standard and the predetermined deformation level, according to the specific shape of the raw pipes. It is therefore necessary to give the overall yielding criterion for expanding and the local rupture criterion for possible cracking. Based on the basic deformation law and main features of pipe, a conception that the deformation process can be divided into two stages was established. After the stress analysis of the part at the stages, the overall yielding criterion for expanding and the local rupture criterion for possible cracking were established.
Key words: mechanical expanding; stress analysis; forming criterion; cylindric products
