摘要
对TP347H钢标准试件进行常温疲劳试验,在金相显微镜下观察分析疲劳裂纹的萌生及扩展规律,并研究显微组织对疲劳裂纹生长过程的影响。研究发现:疲劳裂纹萌生于微观组织结构不连续区域,如晶界、孔洞、夹杂等,开始时沿与载荷轴呈45°方向扩展,之后扩展方向逐渐垂直于主应力方向;相邻裂纹间会发生合体行为,且由于裂纹间干涉作用导致部分裂纹扩展缓慢,甚至不扩展;当疲劳裂纹进行穿晶扩展时,裂纹会在晶界处发生偏折后进入相邻晶粒。
The fatigue test of TP347H steel standard specimens were carried out at room temperature.The initiation and propagation of fatigue cracks were observed and analyzed under metallographic microscope,and the influence of microstructure on the fatigue crack growth process was studied.The results show that fatigue cracks originate in discontinuous areas of microstructure,such as grain boundaries,pores,inclusions,etc.At first,the crack propagates along the direction of 45 degrees with the load axis,and then the propagation direction is gradually perpendicular to the direction of the principal stress.Fit behavior occurs between adjacent cracks,and some cracks propagate slowly or even not due to intercrack interference.When the fatigue crack propagates transgranular,the crack deflects at the grain boundary and then enters the adjacent grain.
作者
张羽飞
王璐
方正
ZHANG Yufei;WANG Lu;FANG Zheng(School of Energy and Power,Dalian University of Technology,Dalian 116024)
出处
《现代制造技术与装备》
2021年第5期47-50,共4页
Modern Manufacturing Technology and Equipment
基金
高强度铝合金疲劳行为的微观组织交互影响机理研究(20180550726)。
关键词
TP347H钢
裂纹萌生扩展
显微组织
晶界
TP347H steel
crack initiation and propagation
microstructure
grain boundaries
