Research Of Remanufacturing Roll Based On Laser Cladding Technology

Roll is the key working parts in rolling equipment, it bears huge shear stress and compressive stress in the process of working, hot roll also bear high temperature oxidation and corrosion. Roll surface will generate abrasion, crack and flake very easily in the bad working condition, the mar not only affect blank quality and lower production efficiency, but also increase the cost of steel production. In order to extend the life of roll and economize the cost of steel production, usually coating a layer of high intensity alloy powder on the roll surface. In this dissertation, using the superiority of laser cladding, designing two kinds of high intensity alloy powder, by a lot of experiments, the feasibility of alloy powder for roll remanufacturing is proved. The primary coverage as follows:The composition of high-power semiconductor laser, parameters and the property of light source are researched, the mar of roll are analyzed for establishing the roll remanufacturing foundation. The process of roll remanufacturing based on laser cladding is simulated by ANSYS APDL, temperature field and stress field generated in the laser cladding process are researched, and the stress field after cooling down is also analyzed. The feasibility of roll laser cladding remanufacturing is proved from numerical simulation.The elements and physical properties of 140 Cr Ni Mo rolls are analyzed, based on existing laser cladding material, engineering experience and the design principles of alloy powder, two kinds of high intensity alloy powder are designed. Adopting one single variable method, the effect of laser power, cladding speed, powder speed and lap rate on cladding quality are researched, laser cladding parameters are improved, a better crafts parameter is obtained at last.Based on the high intensity alloy powder and cladding crafts, the coating of laser cladding is manufactured by high-power semiconductor laser. Research and analysi are conducted about mechanical properties by way of micro-hardness test, impact test, friction-wear test, tensile test and gleeble test. Fracture morphology and microstructure of the two coatings are analyzed. Comprehensive mechanical properties of the two coatings are obtained, the feasibility of alloy powders for laser cladding remanufacturing 140 Cr Ni Mo rolls is proved.