Research on the Welding Process of High Nitrogen Steels with Mid-thickness by MIG Welding
【摘要】：The process parameters were optimized by bead weld in high nitrogen austenitic stainless steel with 12mm thickness. High nitrogen austenitic stainless steel plates with 20mm and 40mm thickness were welded with the optimum process parameters. The mechanical properties of weld joints were inspected. The experimental results indicate that the best process parameters of bead weld are that welding current is 260 A, welding speed is 600 mm.min-1 , the flow rate of gas is 20 L.min-1 , and torch height is 15 mm, the angle of welding torch is 6 degree. The internal qualities of weld bead were beyond the grade Ⅱ and heat-affected zone were small. The mechanical properties of welded joints were excellent. For instance, the tensile strength can achieved move 80% than that of the base metal and the impact absorbing energies also approach 50% than that of the substrate metal. The optimum process parameters can effectively solve the problem of welding process of high nitrogen steels with mid-thickness by MIG welding.