铜基耐蚀合金熔覆层的制备及耐蚀特性

Preparation and Corrosion Resistance of Laser-Cladded Cu-Based Alloy Coatings on Q235 Steel

摘要:

采用光纤激光器，在不同功率下在Q235钢表面制备了铜基合金熔覆层。利用扫描电镜、能谱仪、X射线衍射仪和电化学工作站分别对熔覆层的显微结构、相组成及耐蚀性能进行表征。结果表明，熔覆层与基体冶金结合。熔覆层底部为胞状组织，中部为树枝晶和柱状晶。熔覆层主要包含富铜Cu(Ni, Fe)固溶体和富铁Ni(Cr, Mo, Fe)固溶体。由于其最高的自腐蚀电位和最低的自腐蚀电流，2000 W功率下所制备的熔覆层表现出最好的耐蚀性能。

Abstract:

Copper-based coatings were prepared on the surface of Q235 steel by fiber laser under different powers. Microstructure, phase composition, corrosion resistance of the coatings were revealed by scanning electron microscopy (SEM) equipped with energy dispersive spectrometry (EDS), X-ray diffraction (XRD) and electrochemical workstation, respectively. Results show that the coatings are well bonded to the substrate. The coating microstructure consists of cellular, coarse dendrites, fine dendrites and columnar grain structure from the bottom to the top. The coatings mainly contain two phases including Cu(Ni,Fe) and Ni(Cr,Mo,Fe) solid solution. The coating with two layers prepared under 2000 W exhibits optimal corrosion resistance due to its highest corrosion potential and lowest corrosion current density.