超声喷丸对工业纯Zr疲劳裂纹扩展行为的影响  

Effect of Ultrasonic Shot Peening on Fatigue Crack Growth Behavior of Commercial-Purity Zr

作　　者：朱文光 张鑫[1,2] 宋慷慨 王遂 曾祥康 马驰 张聪惠 Zhu Wenguang;Zhang Xin;Song Kangkai;Wang Sui;Zeng Xiangkang;Ma Chi;Zhang Conghui(School of Metallurgical Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;Northwest Institute for Nonferrous Metal Research,Xi'an 710016,China;State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment Materials,CNPC Tubular Goods Research Institute,Xi'an 710077,China)

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055 [2]西北有色金属研究院,陕西西安710016 [3]中国石油天然气集团公司管材研究所石油管材及设备材料性能与结构安全国家重点实验室,陕西西安710077

出　　处：《稀有金属材料与工程》2023年第8期2711-2720,共10页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China(51674187);International Science and Technology Cooperation Projects of Shaanxi Province(2021KW-27);The Key Industry Chain(Group)-Industrial Field in Shaanxi Province(2019ZDLGY05-03)。

摘　　要：对厚度为2.0 mm的工业纯锆板材进行双面超声喷丸(USSP)处理,研究了超声喷丸(USSP)对微观组织演变和疲劳裂纹扩展(FCG)行为的影响。通过光学显微镜、激光共聚焦显微镜、背散射电子衍射仪、透射电子显微镜和X射线衍射仪分别对微观结构演变进行表征。采用紧凑拉伸试样进行FCG试验,对断口形貌和裂纹扩展路径进行分析。结果表明,USSP处理后形成了具有约250μm深度残余压应力的表面梯度结构,USSP试样比原始试样表现出更高的强度和表面粗糙度。值得注意的是,USSP-8 min和USSP-12 min试样的疲劳裂纹扩展寿命比原始试样分别提高了28.1%和50.9%。USSP处理有助于提高疲劳裂纹扩展抗力,进而在一定程度上降低疲劳裂纹的扩展速率。FCG性能的提高可归因于残余压应力和晶粒细化的共同作用,残余压应力增强了裂纹闭合效应,降低了有效应力比。同时,晶粒细化使晶界比例增加,循环塑性区尺寸减小,从而有利于抵抗裂纹扩展。Double-side ultrasonic shot peening(USSP)was performed on a commercial-purity Zr plate with 2 mm in thickness.The effects of USSP on microstructure evolution and fatigue crack growth(FCG)behavior were investigated.Microstructure evolution was characterized by optical microscopy,laser confocal microscope,electron back-scatter diffraction,transmission electron microscope,and X-ray diffractometer.FCG tests were carried out using compact tension samples,the fracture morphology and crack growth path were analyzed accordingly.The results show that a refined surface gradient structure with compressive residual stress of about 250μm in depth is formed after USSP treatment.The USSPed samples exhibit higher strength and surface roughness than the as-received samples.Notably,the fatigue crack growth life of USSP-8 min and USSP-12 min samples is increased by 28.1%and 50.9%compared to that of the as-received samples.The USSP treatment helps to improve the resistance to fatigue crack propagation,which in turn reduces the fatigue crack growth rate to a certain extent.The enhancement of the FCG performance can be ascribed to the combined effects of the compressive residual stress and the conspicuous grain refinement.Compressive residual stress enhances the crack closure effect and decreases the effective stress ratio.Meanwhile,grain refinement increases the fraction of grain boundary and decreases the cyclic plastic zone size,which is beneficial for crack growth resistance.

关 键 词：超声喷丸(USSP) 工业纯Zr 疲劳裂纹扩展 晶粒细化 残余应力 

分 类 号：TG668[金属学及工艺—金属切削加工及机床] TG146.414[一般工业技术—材料科学与工程]