Research On Laser Cladding Cr-Ni Coating On The Surface Of T10 Steel And 45 Steel

T10 steel and 45 steel are widely used in various fields of industrial production due to their excellent comprehensive properties and low manufacturing costs,but these two steels usually face various complex service environments such as wear,corrosion.Laser cladding surface modification is a better way to broaden its application scope and avoid huge economic losses caused by material failure.In this paper,pure Cr and pure Ni powders are mixed in different proportions to make cladding materials.The laser cladding process parameters and cladding material composition are adjusted to study the changes in macroscopic morphology,microstructure,phase composition,hardness,abrasion and corrosion resistance.The test results show that the phases of the cladding layer of T10 steel and 45 steel are composed of alloyed austenite phase and ferrite phase,and their microstructures morphologies show eutectic morphology.The distribution of dendrite and grain boundary positions in the layer is very different.When the ratio of Cr / Ni in the mixed cladding material is reduced from 9: 1 to 7: 3,the ferrite phase content in the cladding layer decreases accordingly,and the austenite phase content changes in the opposite direction.The research on the macroscopic morphology of the cladding layer shows that if the other variables are kept constant,the larger laser power or the smaller laser scanning speed,the wider melt path width will be due to the increase in absorbed laser energy.The depth of the molten pool will increase with the increase of laser power and the decrease of laser scanning speed.V-shaped textures appear on the surfaces of different melt channels,which are mainly caused by the directional pull of the laser beam to the molten pool and the difference in surface tension gradient in the molten pool.The hardness test results of the cladding layer of T10 steel and 45 steel show that the hardness of the cladding layer is higher than that of the substrate,which is about twice that of the substrate.Solid solution strengthening and rapid cooling of the laser molten pool are the main reasons for the increased hardness of the cladding layer.The laser power and laser scanning speed have little effect on the hardness of the cladding layer,but the hardness of the cladding layer will increase with the increase of the Cr content in the cladding material.The test results of the wear resistance of T10 steel and 45 steel show that the wear resistance of the cladding layer of the T10 steel substrate is better than that of the substrate,and the change law basically shows that the wear resistance gradually increases with the increase of Cr content in the cladding layer.However,the cladding layer of the 45 steel only has the wear resistance of the samples with cladding material powder ratios of 9: 1 and 8: 2,and the wear resistance of the cladding material powder ratio 7: 3 is consistent with matrix.The test results of the corrosion resistance of the T10 steel show that the corrosion resistance of the test samples after laser cladding treatment is significantly improved compared to the substrate.The corrosion resistance of the cladding layer increases as the proportion of Cr in the cladding material increases.This is mainly because the Cr element in the cladding layer provides a passivation film for the surface of the cladding layer and protects the substrate from corrosion.