喷丸强化对17-4PH不锈钢室温及高温疲劳性能的影响  

Effect of Shot Peening on Fatigue Properties of 17-4PH Stainless Steel at Room Temperature and High Temperature

作　　者：刘明霞[1] 王冬 张文康 畅庚榕[1] 刘道新[3] 徐可为[1,4] LIU Mingxia;WANG Dong;ZHANG Wenkang;CHANG Gengrong;LIU Daoxin;XU Kewei(Shaanxi Key Laboratory of Surface Engineering and Remanufacturing,Xi’an University,Xi’an 710065,China;Xi’an Shaangu Power CO.,LTD,Xi’an 710082,China;School of Aeronautics,Northwestern Polytechnical University,Xi’an 710072,China;State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安文理学院陕西省表面工程与再制造重点实验室,西安710065 [2]西安陕鼓动力股份有限公司,西安710082 [3]西北工业大学航空学院,西安710072 [4]西安交通大学金属材料强度国家重点实验室,西安710049

出　　处：《材料导报》2020年第22期22124-22129,共6页Materials Reports

基　　金：陕西省科技计划项目(2018JM5105,2018JQ5173,2013JM6002,14JK2122);陕西省教育厅科技项目(18JS096,18JS099);西安市科技计划项目(2019KJWL06,GXYD16.2);西安文理学院大创和科研团队项目(DC2019050,XAWLKYTD013)。

摘　　要：对17-4PH不锈钢进行不同喷丸强度的表面强化,采用X射线衍射仪(XRD)、光学显微镜(OM)和显微硬度仪研究表面残余应力、表面形貌和表面硬度的变化规律,采用疲劳实验和扫描电镜(SEM)考察室温及150℃、300℃和450℃不同温度场对疲劳性能的影响。结果表明,低强度喷丸通过引入残余应力场和保留表面完整性显著改善17-4PH的室温疲劳寿命;随着喷丸强度的增大,表面粗糙度呈升高趋势,加工硬化层的深度也趋于增加;但当喷丸强度超过中等强度水平,表层硬度不再增大;在疲劳寿命方面,不同温度场对17-4PH喷丸强化效果影响不同,当环境温度低于300℃时,喷丸能显著提高17-4PH的疲劳寿命,超过450℃时,疲劳性能显著降低。进一步分析表明,17-4PH高温疲劳性能的下降源于残余应力的严重松弛和表面完整性的降低。Surface strengthening of 17-4PH stainless steel with different shot peening(SP)strengths was studied in the present paper.Variation of surface residual stress,surface morphology and surface hardness were investigated by X-ray diffraction(XRD),optical microscopy(OM)and microhardness tester.The effects of different temperature fields on fatigue properties of SP 17-4PH stainless steel were studied by fatigue test and scanning electron microscopy(SEM).The results show that low strength SP can significantly improve the fatigue life of 17-4PH at room temperature by introducing residual stress field and retaining surface integrity.With the increase of SP strength,the surface roughness increases and the depth of working hardened layer tends to increase.However,when SP strength exceeds the medium strength level,the surface hardness no longer increases.In terms of fatigue life,different temperature fields have distinct effects on SP 17-4PH steel.When the ambient temperature is lo-wer than 300℃,the fatigue life of 17-4PH could be significantly increased by SP treatment,while the fatigue performance would be obviously reduced when the temperature is higher than 450℃.Further analysis shows that the decrease of high temperature fatigue properties of 17-4PH results from the serious relaxation of residual stress and the decrease of surface integrity.

关 键 词：喷丸 疲劳 残余应力 表面完整性 高温 

分 类 号：TG668[金属学及工艺—金属切削加工及机床]