疲劳对金属塑性变形及延性断裂过程的影响

通过慢速拉伸曲线,研究金属的塑性变形过程和延性过程中细微的变化,以及疲劳对它们的影响。在对金属材料做静拉伸试验时,在一般速率拉伸和在慢速拉伸下,所得到的拉伸曲线的表现是不同的。比较了拉伸速率10mm/min和0.2mm/min的拉伸曲线,在弹性变形范围内,2种速率下的曲线基本上是一样的;在塑性变形阶段,慢速拉伸曲线将随着载荷的增加,曲线逐渐变粗,当通过最大载荷点1段后,曲线变到最粗,然后变成1条线;在断裂阶段,曲线出现间断卸载的叉枝,直到断裂。

Effects of Fatigue on Process of Plastic Deformation and Ductile Fracture of Metal

Through slow pulling cured shape, the plastic deformation process and micro changes during ductile process of metal and the effects of fatigue to them were researched. The show of pulling curved shape is different under normal pul- ling speed and slow pulling when doing statistic pulling test of metal materials. The paper took comparing of the puling curved shapes of pulling speed of 10 mm/min and O. 2 mm/min, which are the same in the regime of elastic deformation.The curved shape became thick with the increasing of loads of slow pulling curved shape, when it go through the biggest point about 1 section, the curved shape changed thickness, and then it changed into one line. In fracture phase, curved shape shows discontinuous and unloading branch, even to fracture.