冲击条件下纯铁晶粒尺寸增大和减小现象研究

The Study of Phenomena for Increase and Reduce of Grain Size of Pure Iron at Impact

在 Hopkinson 压杆上以不同速度对经过两种热处理的纯铁试样进行冲击测量其动态屈服强度,对冲击前后的试样进行微观组织观察,发现无论是经过充分退火还是不充分退火的试样,随着冲击速度的上升,动态屈服强度都上升,但前者的晶粒尺寸减小,而后者的晶粒尺寸却增大(有些晶界消失)。并对其形成过程进行了分析。

Dynamic strength of specimens,that is heated by duble-type heat treatment process,has tested at Hopkinson pole with difference velocity.Microstructure of impact fore-and-aft specimens is observed.Dynamic strength is all raising along with raising of impact velocity for difference heat treatment process.But grain size of fill anneal specimens is reduced,Grain size of ill anneal specimens is increased(few crystal bound has disappeared).And analyses of forming process.