熔覆电流对高钼高钒铁基硬质涂层组织结构与性能的影响OA

To improve the wear resistance of cutting edge plates on digging buckets,Fe-based hard coatings with high Mo and V contents were prepared on Q345B steel by plasma cladding technology.The effects of cladding current(120,140,160 A)on the structure of the coatings were analysed,and the hardness,wear resistance and impact resistance of the coatings were investigated.The results show that the cladding current has a significant influence on the microstructure and interface quality of the coatings.The coatings mainly consist of a martensitic matrix with distributed fine spherical VC particles,polygonal Mo2B and lamellar composite M2(B,C).Localized unfused zones are observed at the interface between the substrate and the coating prepared at 120 A.As the current increases,the size of the VC particles in the coatings increases,their distribution density decreases,and the size of Mo2B decreases or even disappears in the coating prepared at 160 A,while the size of M2(B,C)increases and the number increases.The average hardness of the coatings is approximately 920 HV0.1,which is more than twice that of NM400 steel,and the weight loss is only 1/20 of that of NM400 under the same abrasion conditions,showing better wear resistance.The coating specimens exhibit good impact resistance,and the coatings with parallel cladding patterns are superior to those with vertical cladding patterns.