激光熔覆FeCr和CoCr合金涂层的组织与性能

Microstructure and properties of FeCr and CoCr laser cladding coatings

对启闭机活塞杆用40Cr不锈钢基体采用激光熔覆技术分别制备FeCr合金层和CoCr合金层。表征和分析钴基和铁基合金涂层的微观组织结构、显微硬度、孔隙率、抗冲击韧性、抗磨损性能。结果表明:激光熔覆技术获得的FeCr和CoCr合金熔覆层的孔隙率趋近于零,FeCr和CoCr合金熔覆层的平均显微硬度分别达718.6 HV0.2和541.4 HV0.2。FeCr合金熔覆层的冲击凹坑深度约45μm、直径约3.6 mm,CoCr合金冲击凹坑深度约60μm、直径约4.5 mm,FeCr合金熔覆层抗冲击韧性优于CoCr合金熔覆层;经过180 min摩擦磨损实验后,FeCr合金熔覆层质量损失为0.00201 g,CoCr合金熔覆层质量损失为0.00347 g,基体40Cr质量损失为0.08108 g,从抗磨性能比较FeCr合金熔覆层>CoCr合金熔覆层>基体40Cr不锈钢。40Cr不锈钢、FeCr合金、CoCr合金熔覆层的磨损机理主要是犁削和黏着磨损。

FeCr and CoCr cladding coatings were prepared by laser cladding technology on 40Cr steel substrate for hoist piston rod.The microstructure,microhardness,porosity and wear resistance of cobalt based and iron-based alloys were characterized and analyzed.The results show that the porosity of FeCr and CoCr alloy cladding coatings obtained by laser cladding technology approaches to zero.The average microhardness of FeCr and CoCr alloy cladding layer are 718.6 HV0.2 and 541.4 HV0.2,respectively.The impact toughness of FeCr alloy cladding layer is better than that of CoCr alloy cladding layer.After 180 min friction and wear test,the mass loss of FeCr alloy cladding layer is 0.00201 g,the mass loss the CoCr alloy cladding layer is 0.00347 g,and the mass loss of the matrix 40Cr is 0.08108 g.The wear resistance of FeCr alloy cladding layer is better than that of CoCr alloy cladding layer and also better than 40Cr stainless steel.The wear mechanism of 40Cr steel,FeCr alloy and CoCr alloy cladding layer is mainly micro ploughing and adhesive wear.