激光冲击强化前处理对AISI9310齿轮钢低温渗碳的影响  

Effects of Laser Shock Peening on Low Temperature Carburizing of AISI9310 Gear Steel

作　　者：宋靖东 何卫锋[1,2,3] 罗思海 曹振阳[1,2] 梁晓晴[3] SONG Jingdong;HE Weifeng;LUO Sihai;CAO Zhenyang;LIANG Xiaoqing(National Key Lab of Aerospace Power System and Plasma Technology,Xi’an Jiaotong University,Xi’an 710049,China;School of Mechanical Engineering,Xi’an Jiaotong University,Xi’an 710049,China;National Key Lab of Aerospace Power System and Plasma Technology,Air Force Engineering University,Xi’an 710038,China)

机构地区：[1]西安交通大学航空动力系统与等离子体技术全国重点实验室,西安710049 [2]西安交通大学机械工程学院,西安710049 [3]空军工程大学航空动力系统与等离子体技术全国重点实验室,西安710038

出　　处：《中国表面工程》2023年第6期155-162,共8页China Surface Engineering

基　　金：国家重大科技专项(2017-VII-0003-0096);国家自然科学基金(52005508);中国科协青年人才托举工程(YESS20200321)资助项目。

摘　　要：AISI9310钢是一种高强度渗碳齿轮钢,具有较好的韧性。服役过程中,齿面极易发生磨损和接触疲劳失效损伤。为有效改善9310齿轮钢的耐磨损和抗接触疲劳性能,实现磨损和接触疲劳性能协同强化,提出采用激光冲击(LSP)+渗碳(LC)复合强化的技术思路,采用激光冲击强化技术对AISI9310钢基体进行前处理,再对其开展低温渗碳热处理。为进一步研究LSP和LC对9310齿轮钢微观组织形貌的影响规律,利用光学显微镜、扫描电子显微镜和电子背散射衍射表征渗碳层微观组织形貌和截面方向的晶体学特征,并对试件截面方向的硬度进行考核。研究结果表明,AISI 9310钢的渗碳层厚度约为14μm,最大硬度约为305.67 HV,硬化层厚度约300μm;LSP前处理后,渗碳层厚度提升到23μm,最大硬度提升到328.87HV,硬化层厚度提升到约700μm。对比发现,LSP前处理分别可将9310钢低温渗碳层厚度提升64.3%,渗碳层硬度提升23.17 HV,硬化层深度提升133%。这主要是低温渗碳对9310钢的Kernel平均取向差(KAM)和小角度晶界影响较小,但是LSP前处理可引入塑性变形并提升小角度晶界比例,有助于碳元素扩散,促进9310钢低温渗碳行为,提升渗碳层厚度、硬化层硬度和厚度。初步解决了LSP前处理诱导微观组织缺陷促进碳元素扩散的问题,可为LSP复合强化提升航空齿轮关键部件服役寿命提供技术支撑。AISI 9310 steel is a kind of high-strength carburized steel with good toughness.Owing to its material properties,this steel is usually used to fabricate gear parts.Gear tooth surface is prone to wear and contact fatigue damage during service processing.Therefore,to effectively resolve the resistance properties and for the synergistic strengthening of the wear and contact fatigue properties,the AISI 9310 steel sample was processed by laser shock peening(LSP) and then treated by low temperature gaseous carburization(LC).The carburized layer and cross-sectional crystallographic characteristics were imaged using optical microscopy(OM),scanning electron microscopy(SEM),and electron backscatter diffraction(EBSD);subsequently,the cross-sectional hardness was measured.The following results were obtained.After LC treatment,a white carburized layer,which was approximately 14-μm thick and uneven,was induced on the 9310 steel matrix surface.The maximum hardness achieved for the carburized layer of 9310steel was about 305.67 HV with the depth of work hardening being 300 μm.The maximum hardness of the LCed sample was enhanced by 27.56% compared to the as-received sample.However,with pre-LSP treatment,the thickness of the carburized layer of 9310 steel was improved to approximately 23 μm and the maximum hardness to approximately 328.87 HV with the depth of work hardening being 700 μm.The maximum hardness of the LSP-LCed sample was enhanced by 5.46 % compared to the LCed sample.However,in comparison,the pre-LSP treatment improves the thickness of the carburized layer by 64.3%,the maximum hardness by 23.17 HV,and the depth of work hardening by 133%.The underlying reasons for these enhancements are as follows.Generally,LSP treatment induces plastic deformation and improves the proportion of low angle grain boundary(LGB);this enhances the diffusion behavior of the carbon atoms,and consequently improves the hardness of the LCed layer and the depth of work hardening.After pre-LSP treatment,the carbon diffusion behavior and hardne

关 键 词：激光冲击强化 低温渗碳 AISI 9310钢 小角度晶界 硬度 

分 类 号：TG156[金属学及工艺—热处理] TB114[金属学及工艺—金属学]