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为了提高蠕铁气门座圈密封锥面的耐磨性,采用3kW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6.64GPa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 200W、旋转速度3r/min、送粉量10g/min、保护气流量7L/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 the wear resistance of vermicular valve seat sealing conical surface, Stellite 1 cobalt-based alloy powder was laser cladded on the valve seat conical surface with 3kW solid fiber laser. The laser power, rotation speed, Powder feeding and shielding gas flow and other technological factors on the hardness, microstructure and crack defects. The results show that the average hardness of the coating is more than 6.64GPa, which is 2.32 times higher than that of the matrix. The metallurgical bond between the cladding layer and the substrate can be obtained. The optimum process of laser cladding cobalt-based alloy with vermicular iron valve seat is obtained As: laser power 1 200W, rotation speed 3r / min, feeding powder 10g / min, protection gas flow 7L / min. The valve-seat / valve-seat impact-wear simulation test was carried out on the clad valve seat prepared by the above-mentioned process, and compared with the untreated valve seat. The results show that: the compacted graphite valve seat laser cladding cobalt base After the alloy coating its wear resistance is untreated valve seat 2.87 times.