316L奥氏体不锈钢表面激光熔覆Fe基涂层的组织及耐磨性能研究

    Study on Microstructure and Wear Resistance of Fe-based Coating Laser-cladded on Surface of 316L Austenitic Stainless Steel

    • 摘要: 通过激光熔覆技术采用同轴送粉法在316L不锈钢表面分别制备了不同WC含量和TiC含量的Fe基多道搭接熔覆层。结果表明,在激光功率为1200 W、扫描速度为5 mm/s、光斑大小为2 mm、离焦量为19 mm、送粉速度为0.15 g/s时,激光熔覆层的宏观质量较好。在铁基合金粉末中加WC或TiC粉末后,各熔覆层的组织生长特征较为相似,即熔覆层与基体交接处熔体凝固形式为平面晶,熔覆层底部为胞状晶,中部为柱状枝晶,顶部为等轴枝晶,熔覆层中的晶粒得到细化,熔覆层的硬度和耐磨性得到提高。当添加相同含量的WC和TiC粉末时,添加TiC后的复合涂层硬度和摩擦磨损性能更好。

       

      Abstract: Fe-based multi-channel lap cladding layers with different WC contents and different TiC contents were prepared on 316L stainless steel surface by laser cladding technology and coaxial powder feeding method. The results show that the macroscopic quality of the laser cladding layer is better when the laser power is 1200 W, the scanning speed is 5 mm/s, the spot size is 2 mm, the defocusing amount is 19 mm, and the powders feeding speed is 0.15 g/s. The microstructure growth characteristics of each cladding layer are relatively similar when adding WC or TiC powders to the iron base alloy powder. The melt solidification forms at the junction between the cladding layer and the matrix is planar crystal, the bottom of the cladding layer is a cellular crystal, the middle part is columnar dendrite, and the top is equiaxed dendrite. After adding WC or TiC to the Fe-based powders, the grains in the cladding layer are refined, and the hardness and wear resistance of the cladding layer are improved. TiC-reinforced composite coating exhibits better hardness and friction-wear properties when adding the same content of WC and TiC powders.

       

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