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）

发布时间：2018-06-21 09:35

本文选题：哈氏合金熔覆层 + 激光熔覆　；参考：《Transactions of Nonferrous Metals Society of China》2017年03期

【摘要】：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。
[Abstract]:In order to improve the corrosion resistance of carbon steel, a high power CW laser cladding rate of 6 mm/s and 12 mm/s was used to successfully fabricate the Hashi alloy coating on the E235 low carbon steel substrate. The interface between the laser cladding layer and the steel substrate was obtained after the E235 steel substrate was dissolved in dilute nitric acid solution. The microstructure, chemical composition and mechanical properties of the interface were systematically studied. It is found that there is a special "edge" at the grain boundary of the coating / substrate interface, which is composed of the real grain boundary and the corrosion trace left by the grain boundary corrosion. The interface mainly presents austenitic structure caused by the rapid cooling after laser cladding and the diffusion of Ni to the interface. In addition, the coating prepared at a laser cladding rate of 12 mm/s and its interface have higher hardness than those prepared at 6 mm/s, and the grain boundary at the coating / substrate interface has a higher friction coefficient than the corresponding grain size. At the same time, the faster the laser cladding speed, the smaller the grain size at the interface, the lower the diffusion rate of Ni and Fe at the interface, and the better the tribological properties.
【作者单位】：西南石油大学材料科学与工程学院;北京大学工学院材料科学与工程系;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;
【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
【分类号】：TG174.4

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