喷丸表面完整性对K4169合金高温疲劳性能的影响  

Effect of surface integrity induced by shot peening on high-temperature fatigue property of K4169 alloy

作　　者：赵辛雨 田凯 罗学昆 王欣 ZHAO Xinyu;TIAN Kai;LUO Xuekun;WANG Xin(Aero Engine Corporation of China,Beijing 100097,China;Aviation Key Laboratory of Advanced Corrosion and Protection on Aviation Materials,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]中国航空发动机集团有限公司,北京100097 [2]中国航发北京航空材料研究院航空材料先进腐蚀与防护航空重点实验室,北京100095

出　　处：《航空材料学报》2023年第3期42-48,共7页Journal of Aeronautical Materials

基　　金：国家重大科学与技术专项(J2019-Ⅶ-0015-0155,2017-Ⅶ-0001-0094和J2019-Ⅳ-0009-0077);国家自然科学基金面上项目(522710);中国航发创新平台项目(CXPT-2019-034)。

摘　　要：采用表面粗糙度仪、X射线残余应力测试仪和显微硬度计分别对试样表面粗糙度、表面残余应力分布和硬度梯度等表面完整性参数进行表征,研究不同表面完整性状态对K4169合金缺口旋弯试样高温疲劳寿命的影响规律。结果表明:相比未喷丸试样,喷丸试样在632℃、450 MPa条件下的中值疲劳寿命提高了10.2~43.9倍;喷丸后疲劳源数量降至单个,疲劳源萌生位置由表面转移至次表层。喷丸试样表面形成了高幅值的表面残余压应力(–941~–1023 MPa),并产生了一定深度的硬化层(0.10~0.32 mm),较大的喷丸强度获得了较大的硬化层深度;喷丸消除了试样表面加工刀痕,并显著降低了表面应力集中系数;喷丸改善了试样表面完整性,是疲劳寿命提升的主要原因。The surface roughness,residual stress and micro-hardness of K4169 alloy specimens were characterized by roughness tester,X-ray diffraction(XRD)stress tester and micro-hardness tester.The results indicate that median fatigue lives of the specimens increased by 10.2-43.9 times after SP treatments compared with untreated specimens.Furthermore,the number of fatigue source decreased to only one and the site of fatigue source transferred from the surface to the subsurface.The harden layer with the depth of 0.10-0.32 mm and the surface residual stress of−941-−1023 MPa are obtained.The depth of harden layer increased with the increasing of peening intensity.The grooves obtained from the grinding disappeared and the surface stress concentration intensity decreased largely after SP.The improvement of fatigue life is mainly ascribed to the enhancement of surface integrity induced by SP.

关 键 词：喷丸 高温合金 疲劳 表面完整性 

分 类 号：TG668[金属学及工艺—金属切削加工及机床] TG115.57