激光熔覆低碳铁基合金的组织和摩擦磨损性能

Microstructure,Friction and Wear Properties of Low Carbon Fe-based Alloy Prepared by Laser Cladding

采用优选的激光工艺参数和搭接率,在Q235钢板表面制备出低碳铁基合金熔覆层。为了研究熔覆层在干摩擦试验条件下的表面摩擦磨损行为,在MVF-1A型摩擦磨损试验机上分别进行了等速变载荷、等载荷变速条件下的摩擦磨损试验。利用光学显微镜（OM）、扫描电子显微镜（SEM）对熔覆层的微观组织和磨痕表面形貌进行观察。结果表明,低碳铁基合金熔覆层组织均匀致密,其中熔覆区组织为平面晶和树枝晶,过渡区为含Cr、Ni的板条状马氏体。熔覆层摩擦系数随载荷的增加而增加,随转速的增大而略有减小。

Low carbon Fe-based alloy coating was fabricated on Q235 steel substrate surface by adopting optimal laser processing parameters and lap ratio. In order to study the friction and wear behaviors of the cladding layer under dry friction test conditions, the friction and wear tests were carried out on MVF-1 A friction and wear tester under the conditions such as uniform velocity and variable load, and constant load and varying velocity. The microstructure and surface morphologies of wear scar of the laser cladding layer were studied by scanning electron microscopy（SEM） and optical microscope（OM）. The results show that the microstructure of low carbon Fe-based alloy cladding layer is homogeneous and dense. The microstructure of cladding zone consists of planar crystal and dendrite crystal, and the microstructure of transition zone consists of lath martensite with Cr and Ni. The friction coefficient of the cladding layer increases with the increase of load, and slightly decreases with the increase of velocity.