Microstructure and mechanical properties of interface between laser cladded Hastelloy coating and steel substrate  

激光熔覆哈氏合金涂层与基体间界面的显微组织及力学性能（英文）

作　　者：Qin-ying WANG Yu-chen XI Xiao-yu LIU Shuang LIU Shu-lin BAI Zong-de LIU 王勤英;西宇辰;刘晓宇;刘双;白树林;刘宗德(西南石油大学材料科学与工程学院,成都610500;北京大学工学院材料科学与工程系,北京100871;华北电力大学电站设备状态检测与控制教育部重点实验室,北京102206)

机构地区：[1]School of Materials Science and Engineering, Southwest Petroleum University, Chengdu 610500, China [2]Department of Materials Science and Engineering,College of Engineering, Peking University, Beijing 100871, China [3]Key Laboratory of Condition Monitoring and Control for Power Plant Equipment,Ministry of Education, North China Electric Power University, Beijing 102206, China

出　　处：《Transactions of Nonferrous Metals Society of China》2017年第3期733-740,共8页中国有色金属学报（英文版）

基　　金：Project supported by the New Staff Research Start-up Fund and the Innovation Fund(School of Materials Science and Engineering) of Southwest Petroleum University,China

摘　　要：In order to improve the corrosion resistance of carbon steel,Hastelloy coatings were prepared on E235steel substrate by ahigh power diode laser with laser scanning speeds of6and12mm/s,respectively.The interface between the coating and substratewas firstly exposed by dissolving off the substrate.Its microstructure,composition and mechanical properties were systemicallystudied.Special“edges”along the grain boundary were found at coating/substrate interface.These“edges”consisted of intergranularcorrosion area and real grain boundary.The interface of coating mainly displayed austenite structure ascribed to the rapidsolidification as well as the dilution of Ni during preparation.Additionally,Hastelloy coating and its interface prepared at the speedof12mm/s showed higher hardness than that prepared at the speed of6mm/s.Grain boundaries had higher friction coefficient thangrains at both coating/substrate interfaces.Moreover,the interface at higher laser scanning speed exhibited smaller grains,lowerdilution rates of Ni and Fe as well as a better tribological property.为提高碳钢的耐腐蚀性能,利用高功率连续半导体激光器分别以6和12 mm/s的熔覆速度,在E235低碳钢基体上成功制备了哈氏合金涂层。利用稀硝酸溶液溶去E235钢基体后,获得激光熔覆层与钢基体之间的界面,并对该界面的显微组织、化学组分以及力学性能进行系统研究。研究发现在涂层/基体界面上的晶界处,存在着一种特殊"边缘",而这种特殊"边缘"由真实晶界与发生晶界腐蚀后留下的腐蚀痕迹所组成。界面主要呈现出由激光熔覆后迅速冷却和Ni元素向界面扩散而导致的奥氏体组织。另外,以12 mm/s的激光熔覆速度制备的涂层及其界面比6 mm/s情况下制备的涂层及其界面具有更高的硬度,而涂层/基体界面上的晶界与对应的晶粒相比具有更高的摩擦因数。同时,激光熔覆速度越快,界面上的晶粒尺寸越细小,界面处Ni和Fe的扩散速度越低,摩擦学性能越优异。

关 键 词：Hastelloy coating laser cladding INTERFACE MICROSTRUCTURE NANO-SCRATCH 

分 类 号：TG174.4[金属学及工艺—金属表面处理]