【摘要】 Ni35粉末掺杂不同质量分数（0%、25%、50%、75%、100%）高碳铬铁粉末,在27SiMn钢表面进行激光熔覆制备复合涂层。采用OM、SEM、EDS及XRD等手段,表征熔覆层显微组织及物相结构;利用硬度计、磨粒磨损机及电化学工作站等仪器,表征熔覆层力学及腐蚀性能。结果表明:未掺杂时,熔覆层物相主要有γ-Ni、FeNi₃及Cr₂Ni₃,掺杂量为50%时,熔覆层物相有α-Cr和（Cr,Fe）₇C₃生成,同时Cr₂Ni₃相消失;随着掺杂量增加,熔覆层中部板条状组织增多且形貌变得粗大;掺杂量为50%时,熔覆层上部花瓣状组织及中部板条状组织均出现Cr元素富集现象,浅灰色组织为γ-Ni。随着掺杂量增加,熔覆层显微硬度呈上升趋势,磨损率呈下降趋势;掺杂量为25%时,稀释率最大,为20.80%;掺杂量为50%时,熔覆层耐蚀性最佳,腐蚀电流密度最小,约为0.39μA/cm²。更多还原

【Abstract】 The coatings of Ni35 powder doped with different mass fractions（0%, 25%, 50%, 75% and 100%） of high carbon ferrochrome powder were prepared on the surface of 27 Si Mn steel using a laser cladding technique. The microstructure and the phase of the laser cladding layers were studied by OM, SEM, EDS and XRD. The mechanical and corrosion properties of the laser cladding layers were studied by micro-hardness tester, abrasive wear machine and electrochemical corrosion tester. The results show that the phases of the cladding layers without high carbon ferrochrome are γ-Ni, FeNi₃ and Cr₂ Ni₃. When the content of carbon ferrochrome is 50%, α-Cr and（Cr, Fe）₇C₃ is generated while Cr₂ Ni₃ disappears. With increasing the content of high carbon ferrochrome, the lath microstructures increase and coarsen constantly. When the content is 50%, Cr element enrichment happens in the petal-looking microstructure of the upper cladding layer and the lath microstructure of the middle cladding layer, and the light gray microstructure is γ-Ni. And with the content increasing, the micro-hardness increases while the wear rate declines. When the content is 25%, the maximum dilution rate is 20.80% and when the content is 50%, the cladding layer has the best corrosion resistance, and the least corrosion current density, which is ⁰.39 μA/cm².更多还原