渗氮H13钢激光熔覆涂层设计与组织性能分析  

Design and Microstructure Properties Analysis of Laser Cladding Coating on Nitrided H13 Steel

作　　者：胡琦芸 王辰阳 蒋华臻 占剑[1] 李正阳[1] HU Qiyun;WANG Chenyang;JIANG Huazhen;ZHAN Jian;LI Zhengyang(Wide Field Flight Engineering Science and Application Center,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China;College of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049,China;College of Mechanical Engineering,Hebei University of Science&Technology,Shijiazhuang 050018,China)

机构地区：[1]中国科学院力学研究所宽域飞行工程科学与应用中心,北京100190 [2]中国科学院大学工程科学学院,北京100049 [3]河北科技大学机械工程学院,石家庄050018

出　　处：《表面技术》2025年第5期203-216,共14页Surface Technology

摘　　要：目的针对渗氮H13钢激光修复中N容易析出并形成气孔的问题,根据熔池反应热力学原理,设计了含Ti和含Co 2种熔覆材料,研究N的分布和释放机制,在渗氮H13钢基板上获得无明显孔洞、裂纹缺陷且性能优良的激光熔覆复合涂层。方法试验了2种方案,方案一,对基板渗氮表层进行激光重熔预处理,再熔覆H13钢与Stellite钴基合金的混合粉末;方案二,先以不同配比的H13钢与Ti的混合粉末打底,再熔覆H13钢与Stellite钴基合金的混合粉末。通过光学显微镜、扫描电子显微镜、背散射电子衍射、X射线衍射等材料表征手段观测涂层的微结构,进行显微硬度测试和电化学腐蚀试验。结果方案一中,激光重熔预处理会促使N释放,经过激光熔覆后,涂层组织以马氏体为主,存在大片残余奥氏体;方案二中,随着H13钢与Ti混合粉末中Ti元素添加量由0%增加至10%,涂层与基体冶金过渡区存在明显差异,H13+10%Ti涂层组织为马氏体和弥散分布的碳化物,H13+50%Stellite涂层内组织均匀致密,主要为马氏体和残余奥氏体。结论通过激光熔化沉积技术制备了具有较高硬度和较好耐腐蚀性的激光熔覆涂层,解决了渗氮H13钢强化与修复中氮气孔形成以及涂层与基体结合区成分偏析的问题。In the industry,the surface of H13 tool steel is generally nitrided to improve its properties,thus reducing the frequency of maintenance and replacement.As an advanced surface modification technology,laser cladding is widely used in surface strengthening and repairing.However,nitrogen will precipitate and may form nitrogen pores during laser repair of nitrided H13 tool steel.In order to solve this problem,two types of cladding materials containing Ti and Co were designed based on the thermodynamic principle of melt pool reaction.The distribution and release mechanism of nitrogen element were studied.And laser cladding coatings with good properties but no obvious pores and cracks were prepared on nitrided H13 tool steel.Laser cladding experiments were conducted with mixed powder of H13 and Stellite,as well as mixed powder of H13 and Ti as cladding materials.The process was optimized by changing laser line energy density,and the composition was optimized by changing the mass ratio of mixed powder.Then,two schemes were tested.In the first design,laser remelting pre-treatment was carried out on the nitrided surface of the substrate,followed by laser cladding the mixed powder of H13 and Stellite alloy.In the second design,with the mixed powder of H13 and Ti with different ratios as the base material,then the mixed powder of H13 and Stellite alloy was cladded on the base material.The microstructure of samples was characterized by optical microscope,scanning electron microscopy,electron backscatter diffraction and X-ray diffraction.Performance testing included micro-hardness tests and electrochemical corrosion experiments.The average hardness of the nitrided H13 steel was about 530HV.And its corrosion current density was 1.68×10^(-5) A/cm^(2).Generally,during laser cladding on the surface of nitrided H13 steel,nitrogen elements were enriched in the bonding zone,resulting in component segregation and poor corrosion resistance.The results of the first design showed that laser remelting pre-treatment could induce the rele

关 键 词：激光修复 渗氮H13钢 氮析出 涂层设计 显微硬度 电化学腐蚀 

分 类 号：V261.8[航空宇航科学与技术—航空宇航制造工程]