Research On The Technology Of Composite Remanufacturing Based On Submerged Arc Welding And Laser Cladding

Surfacing technology is one of the main ways to improve the surface performance of mechanical parts.At present,the commonly surfacing technology includes electrode arc welding,submerged arc welding,plasma welding,laser surfacing(laser cladding).Laser welding can obtain high performance alloy coating on the substrate surface,such as wear resistance,corrosion resistance,oxidation resistance,thermal barrier,and its superior performance is unmatched by other welding processes.However,the high repair cost of laser welding restricts its wider application in industry,and sometimes single surfacing technology could not always work well.Composite surfacing technology is a kind of welding method which combines different surfacing technology and different surfacing materials to repair parts,and it can give full play to the advantages of surfacing.This thesis study an composite welding technique which combined submerged arc welding and laser cladding by material design,process design and practical application,The cotents are as following.40Cr was chosen as the matrix material.According to the design principle of welding material,the submerged arc welding material and laser cladding material are designed reasonably,and the hardness and wear resistance of the cladding layer were improved by adding SiC powder.Based on the analysis of the surface morphology,surface hardness,phase,microstructure,microhardness and friction and wear properties of the cladding layer,the optimal proportion of SiC was confirmed.The high hardness and wear resistant coating was prepared on the 40 Cr substrate by the design of the composite welding process.The surface quality,microstructure,microhardness and tensile properties of the composite coating were analyzed and compared with that of laser cladding.The technology of laser remelting was used to solve the problem of multi porosity in submerged arc surfacing.Based on the analysis of the function and the failure form of the closely arranged roller in Casting Production,the surface of the roller is repaired and re manufactured by the composite surfacing technology.Through the practice of the factory,it has been proved that this kind of composite surfacing technology can realize the mass repair of the closely arranged rollers,reduce the repair costs,and improve the service life of the roller.