| The central section trough of scraping belt transporter was mainly made of 16Mn steel which wear-out invalidation created huge economic loss every year in coal exploration field. In this research,cladding tests of Ni60A,TiC and Ti-C-Nb were tested by means of argon arc cladding technique to enhance wear resistance of 16Mn steel and the optimum parameters of argon arc cladding was determined. The microstructure of the coating was analyzed by XRD,SEM,TEM and the formation condition and growth mechanism of TiC were investigated. The fesibility was investigated by thermodynamic computing to which TiC is in situ synthesis,too.At the same time friction attrition resistance was tested under different load and time and attrition mechanism was analyzed.Under different thickness of pre-placed coating, welding current and cladding speed,Hardness test results indicated that the optimum parameters is the thickness of pre-placed coating with 1.5mm, the welding current with 120A and the cladding speed with 8.0mm/sMicrostructure and trasmission analysis indicated that the structure of the coating was divided into three regions,namely:the clad zone, the dilution zone and heat-affected zone and a diffusion layer was found at the interface of the heat-affected zone and the the dilution zone. Excellent bonding between the coating and the substrate is ensured by the strong metallurgical interface and the coating is uniform, continuous and almost defect-free. Interior structure of the composite coating appeard visible gradient distribution and there was more particles on the surface layer. Analysis of power spectrum and the phase indicated that the composite coating is consisted of y-Ni, Cr23C6,TiC and (Ti,Nb)C particles. The TiC and (Ti,Nb)C particles are dispersively distributed in intergranular of y-Ni. The TiC and (Ti,Nb)C particles are granular shape,the petal-like shape, flocculation-like and tree-like shape.There was (Ti,Nb)C after Nb solided into TiC particles.The more content of Nb in alloy power, the more content of Nb in (Ti,Nb)C.The interface between TiC particles and the matrix metal remained clean and free from deleterious and amorphous phase.The thermodynamic analysis indicated that in situ synthesis TiC was feasibe by the argon arc cladding. Its growth element was octahedron shape, the growth mechanism included the independent nucleation growth, the precipitation separating out and connection growth. The connection growth was in the forms of octahedron verte-linked connection and edge -shared connection and the growth form was petal-like shape, dendrite and flocculation-like shape. Wear test of the coating indicated that the relative wear resistance of Ti-C coating was 1.5 times compared with Ni60 and 7 times compared with 16Mn steel; the relative wear resistance of Ti-C-Nb coating was 2 times compared with Ni60 and was 11 times compared with 16Mn steel under same wear condition.16Mn steel wear mechanism was peeling-off type of wear, abrasion and adhesion wear; the abrasion mechanism of the Ti-C-Nb coating was micro scratch wear and the oxidation type of wear. The interface between in-situ TiC or (Ti,Nb)C and the based metal was good and no fallen off during the wear process. The composite coating had excellent wear resistance.
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