Optimization of Process Parameters of Laser Cladding 304L Alloy Powder Based on Orthogonal Experiment

In order to find the optimal combination of process parameters for laser cladding 304L alloy powder on the surface of 45 steel, a combination method of single factor test and multi-factor orthogonal experiment was used to perform the single pulse laser cladding experiment. The effects of process parameters (pulse current A, pulse width B, pulse frequency C,defocus distance D, scan velocity E) on the morphology and performance of cladding layer was studied by range analysis, and the optimal combination of cladding parameters is calculated by fuzzy comprehensive evaluation. The results show that different process parameters have different effects on the morphology of the cladding layer and scanning velocity E and defocus distance D are the most important influencing factor of cladding morphology. The effect on cladding width is D> C > A > B > E and the effect on cladding height is E > A > C > D > B. The optimal combination of cladding width is A4B4C4D4E2. The optimal combination of cladding high is A2B1C1D4E1. The comprehensive optimal process parameters are pulse current 210A, pulse width 3.6ms, pulse frequency 16Hz, defocus distance +10mm and scanning speed 240mm/min. The average hardness of the cladding layer, melting pool, heat-affected zone and substrate under the optimal process parameters is 406.2 HV0.5, 470.8 HV0.5, 230.5HV0.5 and 202.0HV0.5, respectively. The 304L cladding layer on 45 steel surface is stable in width, height and surface quality under comprehensive optimal parameters.