【摘要】 为了分析二辊斜轧穿孔时圆管坯中心金属的断裂机制 ,确立穿孔变形的工艺实质 ,用MARC/ Autoforge软件研究了圆管坯斜轧时的应力、应变场及其发展。进一步证实了沿圆管坯横截面直径上的变形强度确实呈 W形分布。同时还发现变形强度以 W形分布形态出现不是必然的 ,还存在 U形分布形态 ,这与穿孔变形工具和轧机调整参数有关。在大多数情况下 ,二辊斜轧圆管坯变形的发展过程是 :与轧辊接触的局部区域发生变形 ,变形随轧件的螺旋前进 ,先出现 U形分布形态 ,最后出现 W形分布形态更多还原

【Abstract】 With a view to establishing the mechanism of center crack during two cross roll piercing, the distribution and development of deformation and stress in tube rounds were studied through the use of FE code MARC/Autoforge. The distribution pattern of W shape over the diameter of tube round as a result of experiment was further verified. Spontaneously it was discovered that the W shaped pattern does not necessarily occur and there is a U shaped pattern. What pattern may present during piercing process mainly depends on both the forming tools and piercer set up. The development stages of deformation distribution probably are: first the local deformation in the zones adjacent to the contact areas with rolls, then the U shaped pattern with screw advancing and last the W shaped pattern.更多还原