Experimental study of laser cladding technology for hydraulic support inhigh corrosive environment

Based on the application of laser cladding technology on hydraulic support in high corrosive coal mine environment,iron-based stainless steel was selected as the research object. The chemical composition of stainless steel was tested by ICP-AES. The cladding layer was characterized by metallographic and SEM images. The influence of chemical elements on the hardness and corrosion resistance of cladding layer was studied by Rockwell hardness method and salt spray test method. The machining technological process after laser cladding was discussed. The results show that the cladding layer is obviously distinguished from the matrix. The metallurgical bonding occurs between the cladding layer and matrix. In addition,the microstructure of cladding layer is off-white marten site,showing dendritic crystal and elliptical and massive distribution. With the increasing of corrosion resisting alloy element Cr,Ni and Co in the stainless steel powder,the corrosion resistance ability of the cladding layer is improved. The hardness of the cladding layer can be changed by adjusting the content of B and C in the stainless steel powder,but the effect of B on the hardness of the cladding layer is more obvious than C. The best corrosion resistance ability can be acquired by controlling the cladding layer hardness in HRC 50 to 55. Through the study of cost and efficiency,vehicle-mill-polishing is the best solution for laser cladding.