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为了解决激光熔覆高硬涂层开裂的问题,采用CO2激光在20CrMnTi钢表面进行了激光熔覆Colmonoy88合金涂层(熔覆层维氏硬度超过了800HV0.1)的研究。采用扫描电镜和能谱分析仪对熔覆层微观组织结构进行了分析,并采用显微硬度计、摩擦磨损试验机等仪器对其性能进行了测试。研究发现提高预热温度可以显著降低熔覆层的开裂倾向,但不足以使熔覆层中裂纹完全消失;而CeO2的掺入也可以减少熔覆层中裂纹数量,且当CeO2的含量w(CeO2)≥0.10%时,熔覆层中裂纹完全消失。试验结果表明,CeO2的掺入能使熔覆层中晶粒得到细化,显微硬度分布变得均匀,耐磨性能得到提高;且当CeO2的添加量为w(CeO2)=0.10%~0.15%时,熔覆层耐磨性能获得最大提高,与未添加CeO2时相比提高了约67%,磨损形式为磨粒磨损。
In order to solve the problem of laser cladding high hardness coating cracking, laser cladding of Colmonoy88 alloy coating (cladding layer Vickers hardness exceeds 800HV0.1) was performed on the surface of 20CrMnTi steel by CO2 laser. The microstructure of cladding layer was analyzed by SEM and EDS, and its properties were tested by using microhardness tester, friction and wear tester and other instruments. It is found that increasing the preheating temperature can significantly reduce the cracking tendency of the cladding layer but not enough to completely eliminate the cracks in the cladding layer. However, the incorporation of CeO2 can also reduce the number of cracks in the cladding layer. When the content of CeO2 w CeO2) ≥0.10%, the crack disappears completely in the cladding layer. The results show that the addition of CeO2 can refine the grain size of the coating, the microhardness distribution becomes uniform and the wear resistance can be improved. When the CeO2 content is 0.10% ~ 0.15 %, The wear resistance of the cladding layer is maximized, which is about 67% higher than that of the case without CeO2. The wear form is abrasive wear.