In this paper,the stress states in ironing are described;the tensile stress formulaeof the cylinder wall are obtained by using upperbound method;and a new ultimate deforma-tion is presented.

• 本文分析了变薄拉深中材料的应力状态，并采用上限法导出了筒壁拉应力解析式，提出了一种新的极限变形率。