Study On Microstructure And Properties Of Laser Welded Joint Of Ultra Thin And Ultra Pure Ferritic Stainless Steel

As a an important engineering material, ferritic stainless steel has many advantages than other metals and alloys which has been widely used in structure of engineering construction, medical equipment, kitchen supplies, weaving spinning industry, petroleum industry, atomic energy, solar water heater and environmental mechanical. But the thermal cycle in welding causes the joint’s grain coarsening, embrittlement and reduces corrosion resistance property, so the welding problem of ferritic stainless steel make the bottleneck of the large-scale development. Due to many advantages laser processing technology has potential advantage for the welding of ultra thin ultra pure ferritic stainless steel.In the present paper, welding properties of ultra thin and ultra pure443ferritic stainless steel are researched using500W pulsed Nd:YAG solid state laser. The microstructure, phase, mechanical properties, fracture morphology, intergranular corrosion and salt spray corrosion of the pulse laser welded P-LBW butt joints were discussed; the microstructure evolution and macro performance of welded joints under the optimum specifications are researched; the performance analysis and evaluation on microstructure and properties of welded joints were compared with argon tungsten arc welding TIG and pulse argon tungsten arc welding P-TIG.The results of the study show that:ferritic phase and small of the rich chromium carbides dispersion and (or) nitrides composition were consised in ultra thin and ultra pure443ferritic stainless steel welded joints, grain size growed obviously in weld Joints. The bulky columnar crystal, on the contrary of the temperature gradient direction, which along the weld junction grow in weld area. In the center of weld has small regional gross equiaxial crystal, The grain...