为了提高蠕铁气门座圈密封锥面的耐磨性,采用3 kW固体光纤激光器在气门座圈锥面激光熔覆Stellite 1钴基合金粉末,采用正交实验的方法分析了激光功率、旋转速度、送粉量和保护气流量等工艺因素对熔覆层硬度、组织和裂纹缺陷的影响。结果表明: 熔覆层平均硬度达6.64 GPa以上,较基体提高了2.32倍以上;熔覆层与基体能形成良好的冶金结合;获得了蠕铁气门座圈激光熔覆钴基合金的最佳工艺为: 激光功率1 200 W、旋转速度3 r/min、送粉量10 g/min、保护气流量7 L/min。对上述工艺制备出的熔覆气门座圈进行了气门/气门座冲击磨损模拟试验,并与未经处理的气门座圈进行了对比试验,结果表明: 蠕墨铸铁气门座圈激光熔覆钴基合金涂层后其耐磨损性能是未处理气门座圈的2.87倍。

In order to improve wear resistance of vermicular iron cone valve seat cone, 3 kW solid fiber laser was used to laser cladding Stellite 1 Co-based alloy powder on valve seat ring cone. The impact of laser power, scanning speed, the amount of powder feeding and protective gas flow and other factors on the cladding layer hardness process, organization and crack defects were analyzed by orthogonal experiment method. The results showed that: the average hardness of cladding is above 6.64 GPa, compared with the base increased by more than 2.32 times; cladding layer and the matrix can form a good metallurgical bonding; Optimum laser cladding on valve seat vermicular iron cobalt-based alloy process is: laser power 1200 W, rotation speed 3 r/min, the amount of feed powder 10 g/min, shielding gas flow rate 7 L/min. The cladding valve seat was made by the above process for the preparation of the valve / valve seat impact wear simulation test, and the comparative tests were conducted with the untreated valve seat, results showed that: the wear resistance compacted vermicular iron valve seat ring after laser cladding Co-based alloy coating which is 2.87 times of untreated valve seat.