论文部分内容阅读
以Ni、Si元素粉末为原料,利用激光熔覆技术在A3钢表面制得了Ni_(31)Si_(12)/FeNi金属硅化物复合材料涂层。分析了该涂层显微组织,采用测定阳极极化曲线的方法评价了该涂层在0.5mol/l H_2SO_4水溶液中的耐蚀性能,考察了添加少量合金元素Cr对涂层耐酸腐蚀性能的影响。结果表明:激光熔覆Ni_(31)Si_(12) /12/FeNi金属硅化物复合材料涂层组织由带状Ni31Si12初生相及带间FeNi/Ni_(31)Si_(12)/12共晶组成,涂层表面平整、组织细小、与基体间为完全冶金结合;涂层组织显微硬度在HV650—75O之间,沿层深分布均匀;涂层组织组成相Ni_(31)Si_(12)/FeNi本身具有良好的耐酸腐蚀性能,具有快速凝固成分均匀的显微组织,激光熔覆Ni_(31)Si_(12)//FeNi金属硅化物复合材料涂层在H_2SO_4水溶液中表现出良好的耐蚀性。合金元素Cr的添加进一步提高了涂层的耐酸腐蚀性能。
Ni_ (31) Si_ (12) / FeNi metal silicide composite coatings were prepared on the surface of A3 steel by laser cladding technique using Ni and Si powders as raw materials. The microstructure of the coating was analyzed. The corrosion resistance of the coating in 0.5 mol / l H 2 SO 4 aqueous solution was evaluated by measuring the anodic polarization curve. The effect of adding a small amount of alloying element Cr on the acid resistance of the coating was investigated . The results show that the microstructure of laser cladding Ni 31 Si 12/12 / FeNi metal silicide composite is composed of Ni31Si12 primary phase and FeNi / Ni31Si12 / 12 eutectic , The coating surface is smooth, the structure is fine, and the metallurgical bond is completely metallurgical with the substrate. The microhardness of the coating is between HV650 and 75O and distributed evenly along the layer. The microstructure of the coating is Ni 31 Si 12 / FeNi itself has a good resistance to acid corrosion and has a rapidly solidified microstructure. The laser cladding Ni 31 Si 12 FeNi metal silicide composite coating shows good corrosion resistance in H 2 SO 4 aqueous solution Sex. The addition of alloying elements Cr further improves the acid resistance of the coating.