Optimization And Performance Of Laser Cladding 15-5PH Alloy Coating On 20Cr13 Stainless Steel Surface

20Cr13 stainless steel has good performance,is mainly used for manufacturing parts that need to withstand high stress loads and weak corrosion resistance environment.Due to the special working conditions of these parts,it is easy for parts to wear and corrosion failure,resulting in economic losses.As a green remanufacturing technology,laser cladding has the advantages of high efficiency,speed,flexibility and environmental protection,and has been widely used in the surface repair of waste products.In this paper,projected was supported by the National Natural Science Foundation of China(51775071),the Innovation and Application Demonstration Project of Chongqing(cstc2018jscx-msyb X0334).15-5PH alloy coating was fabricated on the surface of20Cr13 stainless steel by laser cladding technology,the microstructure and performance of the cladding layer were studied.Firstly,20Cr13 stainless steel was used as the substrate and 15-5PH alloy powder was used as cladding material,the single laser cladding experiment with three factors and five levels was carried out to analyze the effects of laser power,scanning speed,powder feeding speed and other technological parameters on the geometrical quality characteristics of the cladding layer.Compared with the ternary quadratic polynomial model and BP neural network,the BP neural network optimized by Grey Wolf algorithm has better prediction accuracy and generalization ability,and a prediction method of cladding layer geometric quality characteristics based on GWO-BPNN was formed.The best regression prediction model of laser cladding process parameters on geometrical quality characteristics such as cladding height,width,dilution rate and molten pool depth was established.Secondly,in order to solve the multi-objective optimization problem of the process parameters of the single-track laser cladding 15-5PH alloy powder on the surface of20Cr13 stainless steel.The Analytic Hierarchy Process(AHP)was used to establish the comprehensive evaluation index system of the height,width,dilution rate and molten pool depth of the cladding layer,and the Genetic Algorithm(GA)was used to obtain the optimal process parameters portfolio.In order to solve the selection and optimization of lap rate of multiple-track laser cladding 15-5PH alloy powder on the surface of 20Cr13 stainless steel,the flat-top overlapping model of multiple-track cladding layer was established to optimize the lap rate to obtain the best surface flatness of the cladding layer.The verification experiments were carried out to prove that the cladding layer with optimized process parameters reached the expected forming quality conditions.Finally,metallographic analysis,X-ray diffraction,X-ray energy spectrum,microhardness,friction and wear,and electrochemical corrosion were used to analyze the microstructure,elements distribution,microhardness distribution,friction and wear forms,and corrosion resistance of 20Cr13 stainless steel substrate and 15-5PH cladding layer The performance of laser cladding 15-5PH alloy coating on 20Cr13 stainless steel was verified.