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焊接参数在一定程度上决定着焊缝的形貌及力学性能。采用激光-电弧复合焊接方法对高氮钢进行了焊接,研究了不同焊接参数对焊缝形貌及力学性能的影响。研究结果表明:焊缝熔深随激光功率和焊接电流的增加而增大,随焊接速度的增大而减小;焊缝熔宽随激光功率的增大先减小后增大,随焊接电流的增大而增大,随焊接速度的增大其变化趋势相反,当焊接速度ν=0.8m/min时,焊缝熔宽达到最大,其值为11.8mm。同时对不同参数下的焊接接头进行拉伸和冲击试验,结果发现:焊缝拉伸强度随激光功率和焊接速度的增大先增大后减小,随焊接电流的增大而减小;当焊接速度ν=0.8m/min时,平均拉伸强度最大,为875 MPa;焊缝冲击功随激光功率和焊接电流的增大而增大,随焊接速度的增大其变化趋势相反;当焊接电流I=270A时,焊缝平均冲击功最大,为49J;通过扫描电镜对其拉伸、冲击断口进行观察,发现其断裂形式以韧性断裂为主。
Welding parameters to a certain extent determine the shape and mechanical properties of the weld. High-nitrogen steel was welded by laser-arc hybrid welding method, and the influence of different welding parameters on the weld morphology and mechanical properties was studied. The results show that the weld penetration increases with the increase of laser power and welding current and decreases with the increase of welding speed. The weld width decreases first and then increases with the increase of laser power. With the increase of welding current With the increase of welding speed, the changing trend is the opposite. When the welding speed is ν = 0.8m / min, the weld width reaches its maximum, which is 11.8mm. At the same time, the tensile and impact tests of the welded joints under different parameters were carried out. The results showed that the tensile strength of the weld first increased and then decreased with the increase of laser power and welding speed, and decreased with the increase of welding current. When the welding speed is ν = 0.8m / min, the average tensile strength is the largest, which is 875 MPa. The impact energy of weld increases with the increase of laser power and welding current. When the welding speed increases, When the current I = 270A, the average impact energy of the weld is the largest, which is 49J. The tensile and impact fracture of the weld is observed by SEM, and the fracture is dominated by ductile fracture.