摘要
在喷丸强化机理中,除了"应力强化机制"之外,还存在另外一种"组织结构强化机制"。为了证明这一种新强化机制的存在,采用了XRD、喷丸残余应力、显微硬度以及疲劳等各种试验方法,对喷丸靶材表层的组织结构改性后的力学行为进行了试验测定。结果表明:喷丸引入靶材的残余压应力是一种改善疲劳断裂抗力的"应力强化机制",但是它只能改善正断型模式而不能用来改善切断型模式的疲劳断裂抗力。对改善切断型模式的疲劳断裂抗力起决定性作用的是"组织结构强化机制"。因此作者认为,喷丸强化机理中至少存在上述两种强化机制。
In the shot peening strengthening mechanism（SM）, there exisits a new ＂microstructure strengthe- ning mechanism（MSM）＂ except the ＂stress strengthening mechanism（SSM）＂. To prove the MSM, the me- chanical behavior of microstructure modification in the target surface layer were studied by XRD, residual stresses introduced by shot peening（SP）, microhardness, and fatigue tests. The results show that the com- pressive residual stress introduced by SP is one of the SSM, which can only improve the resistance to fatigue fracture with normal tensile fracture mode（NTFM） ; however, it cannot improve the resistance to fatigue frac- ture with shear fracture mode（SFM）. The decisive role for improving the resistance to fatigue fracture with SFM is merely the microstructure strengthening mechanism（MSM）. In author＇s opinion, there exist at least two types of SM stated above for improving the resistance to fatigue fracture.
出处
《中国表面工程》
EI
CAS
CSCD
北大核心
2012年第6期1-9,共9页
China Surface Engineering
关键词
喷丸强化机理
循环塑性变形
应力强化机制
组织结构强化机制
shot peening strengthing mechanism
cyclic plastic de^ormation~ stress strengthing mechanism
microstructure strengthing mechanism
