Study On Laser Cladding 304 Stainless Steel And Its Enhancement By Hot Extrusion

For the poor plastic toughness and prone to cracks of laser cladding materials,in this paper,a research idea to improve the performance of laser cladding materials after post-treatment strengthening was proposed.The 304 stainless steel with good plastic toughness was selected as the research object.The laser cladding process of 304 stainless steel was simulated.The multilayer cumulative laser cladding experiment was carried out.Then the 304 stainless steel cladding layer material was strengthened by hot extrusion.The temperature field in the laser cladding process of 304 stainless steel was obtained by numerical simulation with ANSYS finite element analysis software.The laser cladding experiment to 304 stainless steel under the same conditions as the numerical simulation was carried out.The morphology of cladding layer obtained by the experiment was studied.The microstructure solidification characteristics of the cladding layer during laser cladding were analyzed by combining the temperature field obtained by numerical simulation.The dilution rates obtained by numerical simulation and experiment were compared and analyzed.Then the laser cladding process parameters with the best quality of the cladding layer are determined.The experiment of multilayer accumulation laser cladding to 304 stainless steel was carried out with the optimal laser cladding process parameters.The obtained cladding materials were strengthened by hot extrusion at different temperatures.The microstructure,the tensile properties,microhardness and tensile fracture morphology of cladding layer before and after hot extrusion was analyzed.And then effect of hot extrusion temperature on microstructure and mechanical properties of materials was concluded.In this paper,the laser cladding 304 stainless steel and its hot extrusion strengthening were studied,and the microstructure solidification characteristics of laser cladding process and the influence rule of hot extrusion treatment on the microstructure and property of cladding layer material were obtained,which provided the certain theoretical basis for strengthening the properties of laser cladding material.