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以高纯Cr、Ni、Si粉末为原料,采用激光熔覆技术在奥氏体不锈钢1Cr18Ni9Ti表面原位合成制备金属硅化物涂层,分析涂层微观组织结构并测量其显微硬度。采用阳极极化方法评价涂层在质量分数为3.5%的Na Cl溶液中的电化学耐蚀性。在室温滑动干磨条件下评价其耐磨性,以失重表征耐磨性。利用光学显微镜(OM),扫描电子显微镜(SEM)等手段从显微角度研究涂层的失效行为。结果表明,涂层具有致密的微观多相结构,以Cr_3Si二元金属硅化物为硬质增强相,以Ni基固溶体γ相为塑性增韧基体相。涂层表现出更高的显微硬度。在3.5%Na Cl溶液中涂层形成抗点蚀性能优异的钝化膜,使其具有优异的电化学耐蚀性能。在室温滑动干磨条件下涂层拥有更小的失重以及更稳定的摩擦系数,能够与对磨副GCr15发生更少的粘着,从而表现出优异的耐磨性。
The high-purity Cr, Ni, Si powders were used as raw materials to synthesize the metal silicide coating on the surface of 1Cr18Ni9Ti austenitic stainless steel by laser cladding. The microstructure of the coating was analyzed and its microhardness was measured. Anodic polarization was used to evaluate the electrochemical corrosion resistance of the coating in NaCl solution with a mass fraction of 3.5%. The wear resistance was evaluated under sliding dry grinding conditions at room temperature, and the wear resistance was characterized by weight loss. The failure behavior of the coating was studied microscopically using optical microscope (OM) and scanning electron microscopy (SEM). The results show that the coating has a dense micro-multiphase structure with Cr 3 Si binary silicide as hard reinforcing phase and Ni based solid solution γ phase as plastic toughening matrix phase. The coating shows a higher microhardness. In 3.5% Na Cl solution coating to form a good resistance to pitting corrosion of the passivation film, it has excellent electrochemical corrosion resistance. The coating has less weight loss and a more stable coefficient of friction at room temperature sliding dry grinding conditions and exhibits less wear than the grinder GCr15.