Si C增强镍基耐磨涂层设计及性能分析

摘要

Q235的用途极其广泛，特别是应用于生产机械设备，但在对表面硬度要求较高的工作环境下，Q235钢往往无法满足服役条件。通过在Q235的表面采用T IG焊熔覆碳化硅陶瓷颗粒增强镍基金属复合涂层的方法提高其表面硬度和耐磨性。研究了焊接电流、焊接电压、气体流量、电弧长度和焊接速度等工艺参数对复合涂层涂覆质量的影响；分析了碳化硅陶瓷颗粒与镍基钎料的质量含量配比对复合涂层成型性和力学性能的影响；在此基础上分析了涂层的微观组织形貌、硬度和耐磨性；发现涂层材料在焊接过程中熔合线附近向外逐渐冷却依次形成树枝晶，等轴晶，碳化硅陶瓷颗粒增强镍基金属复合涂层使Q235碳钢表面硬度比母材提高3倍左右，是优良的金属陶瓷涂层钎涂材料。%Q235 was widely used ,especially applied in the production of mechanical equipment ,but in the requirements of the higher work environment for the surface hardness .Q235 steel often cannot meet the service conditions .By using TIG weld cladding SiC ceramic particles reinforced nickel‐based filler metal composite coating method on the surface of Q 235 to improve the surface hardness and wear resistance .It has been studied the influence of welding current ,welding voltage ,gas flow rate and arc length and speed of welding process parameters on the composite coating quality ;It was analyzed the in‐fluence of SiC ceramic particles with the quality of the nickel‐based filler metal content ratio's to the formability and mechanical properties of composite coating ;On the basis of the test ,the microstructure morphology ,hardness and wear resistance of coating were analyzed ;It was found that coating material cool outward to form dendrites ,isometric in turn near the fusion line in the welding process .It is a good metal ceramic coating brazing material that SiC ceramic particles nickel‐based reinforced metal composite coating made the Q235 carbon steel surface hardness three times greater than that of the parent metal .