低碳钢微型试样塑变机制的研究

本文对低碳钢微型试样在扫描电镜装置上所作的动态拉伸观测结果进行的分析表明:物理屈服现象的产生具有尺寸效应,即当试样厚度减至与晶粒尺寸相当时,物理屈服不再出现。表现在起始塑变机制上,则可能的机制是:先发生晶粒倾转,然后才出现晶粒内滑移带。

On the Plastic Deformation Mechanism of a Thin-Fine Specimen of Mild Steel

This paper analyzes the observation results of tensile testing for thinfine specimens of mild steel by using a scanning electron microscope.The analysis shows that the size of a specimen will affect the occurence of physcal yield (upper-lower yield point),i.e.,no physical yield will occur in the specimen when its thickness decreases to such an extent as that equivalent to the grain diameter.This effect on the changes in the mechanism of the initial plastic deformation may be:the grain turning occurs before the formation of a slip band.