Optimization Of Laser Cladding Process Parameters For H13 Steel

H13(4Cr5MoSiV1)alloy die steel as hot as one of the die steel is widely used in die steel,is widely used in die casting of large impact load is touch,forging die,hot extrusion die etc..In practical application,for example,the H13 steel split die plays an important role in the extrusion process of aluminum profile,and the main failure mode is thermal fatigue wear and fracture.Laser cladding is an advanced surface hardening technology,which can solve the problem of the service life of the split die.From the existing research reports,the coating of the high temperature alloy reinforced phase on the surface of H13 steel,especially the research on how to obtain the laser cladding process parameters of the cladding coating is very few.In this paper,the microstructure,phase composition and mechanical properties of the coating were analyzed by laser cladding Ni based alloy coating on the surface of H13 steel.According to the coating size,using data analysis PCA-TOPSIS method,the optimal process parameters are obtained.In order to improve the comprehensive performance of H13 steel in the extrusion die,the service life of the die in production is prolonged,and the optimization of process parameters for laser cladding is also provided.This paper describes the use of orthogonal test analysis of the effect of laser cladding parameters on the cladding size.With the help of optical microscope(OM)and scanning electron microscope(SEM)analysis of the different laser cladding process influence on macroscopic morphology of the coating and the morphological and histological.With the aid of X-ray diffraction(XRD)analysis of the coating composition quantitative analysis;using a microhardness tester was used to characterize the microhardness of the coating section along the depth direction;and the friction of the coating wear performance and fatigue properties at room temperature were characterized.Based on optical microscope and scanning electron microscope,the macro morphology and microstructure of the coating were analyzed,and the influence of different laser cladding parameters on the macro morphology of the coating was analyzed.Using data analysis method PCA-TOPSIS method,based on the geometric size of single track cladding,the optimal process parameters wereoptimized.X-ray diffraction(XRD)fully illustrated in H13 steel added nickel based alloy phase analysis,can be seen in Ni60 A coating is mainly composed of Cr23C6,gamma(Ni)and Ni2 Si and phase composition,H13 steel substrate surface mainly by the CrFe4,Fe3 C and ?-Fe and phase composition.The coating microhardness test results show that the microhardness of the coatings can have significantly improved,the average micro hardness of cladding layer section of up to 800 HV is 3 ~ 4 times of that of the matrix.Coatings in terms of friction wear experimental results show,Ni60 A coating and H13 steel substrate under different load,Ni60 A coating wear does not increased linearly with increasing load,when the load from 1200 g increases to 1600 g,wear volume was significantly larger;when the load exceeds the 1600 g,wear quantity based unchanged to the present.The wear of H13 steel increases with the increase of load,which shows a linear change,that is,the slope of H13 steel is constant.The test results show that the corrosion resistance of coatings,corrosion resistance than the Ni60 A cladding layer is obviously improved.In order to repair the failure of H13 die steel,the introduction of the powder heat density,and dilution rate concept,discusses the function relation between the.The results show that both meet the exponential function relationship,which is proved by the experimental results.H13 steel surface cladding Ni60 A coating fatigue tensile test show that the fatigue life under different process parameters of laser cladding was significantly different from that in the dilution rate at between 30%-35% of the specimen tension and compression fatigue life was up to 70% of the H13 substrate sample life,Ni base alloy in dilution rate controllability proposed theoretical guidance.In order to improve the theoretical guidance of laser cladding remanufacturing technology in hot extrusion die repair.