激光熔覆损伤定量评估研究  

Quantitative evaluation for laser cladding damage

作　　者：华亮[1,2] 王磊 HUA Liang;WANG Lei(College of Locomotive Vehicle,Nanjing Institute of Railway Technology,Nanjing 210031,China;Collaborative Innovation Center on High-speed Rail Safety of Ministry of Education,Nanjing 210031,China)

机构地区：[1]南京铁道职业技术学院机车车辆学院,江苏南京210031 [2]教育部高铁安全协同创新中心,江苏南京210031

出　　处：《光学技术》2021年第4期472-476,共5页Optical Technique

基　　金：江苏省优秀科技创新团队项目(激光增材制造团队);江苏省高等学校自然科学研究面上项目(20KJB580007);江苏省轨道交通控制工程技术研发中心开放基金(KFJ1803)。

摘　　要：通过激光熔覆实验、金相实验、残余应力检测及熔覆试件静拉伸实验,研究了激光熔覆试件机械性能的变化规律。实验发现熔覆试件重熔区有粗大的魏氏体组织产生,熔覆过程在熔覆试件内引入残余拉应力,熔覆试件抗拉强度相较于基体试件有一定程度的降低,熔覆试件伸长率相较于基体试件而言有大幅降低,实验结果表明熔覆试件的各类机械性能较基体材料而言有不同程度的降低,即激光熔覆后基体材料产生了一定程度的损伤。研究对此类损伤进行了定量分析,构建了熔覆损伤定量评估模型,为改善激光熔覆质量提供了理论依据。Through laser cladding test, metallographic test, residual stress detection and static tensile test of cladding specimens, and the variation law of mechanical properties of laser cladding specimens were studied. It was found that the thick weissenite structure was produced in the remelting zone of the cladding specimen, and the residual tensile stress was introduced into the cladding specimen during the cladding process. Compared with the matrix specimen, the tensile strength of the cladding specimen was reduced to a certain extent, and the elongation of the cladding specimen was significantly reduced. The experimental results show that the mechanical properties of the cladding specimens are reduced in different degrees compared with the matrix materials, that is, the matrix materials have a certain degree of damage after laser cladding. Here, this kind of damage is quantitatively analyzed and a quantitative evaluation model of cladding damage is established, which provides a theoretical basis for improving the quality of laser cladding.

关 键 词：激光熔覆 残余应力 抗拉强度 损伤评估 

分 类 号：TB302[一般工业技术—材料科学与工程]