【摘要】 为解决22MnB5高强钢在汽车轻量化领域的高效可靠连接需求，针对现在研究多集中于电阻、激光焊及TIG焊的局限，采用MAG焊对3 mm厚22MnB5钢板进行对接试验，系统研究焊接电流、焊接电压以及焊接速度对接头成形质量及力学性能的影响规律。研究表明，随着焊接电流从120 A增加到160 A时，焊缝形状由V形逐渐转变为X形，热影响区宽度逐渐增加；随着焊接电压由17 V增加到21 V，焊缝宽度逐渐变宽，由5.5 mm增加到6.6 mm；随着焊接速度由450 mm/min逐渐下降250 mm/min时，焊缝正面、背面熔宽均明显增大。当焊接电流为130 A，焊接电压为18 V，焊接速度为400 mm/min时，接头熔透且热影响区和焊缝区宽度较窄，接头成形较好；焊缝区显微组织为粒状贝氏体和针状铁素体；接头拉伸试样在焊缝区发生断裂，抗拉强度为789 MPa，断口以韧窝形貌为主。更多还原

【Abstract】 This study employs metal active gas(MAG)welding to join 3 mm thick 22 MnB5 steel plates, systematically investigating the effects of welding current, welding voltage, and welding speed on weld formation and mechanical properties. The results demonstrate that when the welding current increases from 120 A to 160 A, the weld seam shape transitions from a V-shape to an X-shape, while the heat affected zone(HAZ) width gradually expands. An increase in welding voltage from 17 V to 21 V causes the weld seam to widen progressively from 5.5 mm to 6.6 mm. A decrease in welding speed from 450 mm/min to 250 mm/min results in noticeable increases in both the front and backside weld widths. The optimal welding process parameters—a welding current of 130 A, a welding voltage of 18 V, and a welding speed of 400 mm/min—produce fully penetrated joints with a narrow HAZ and weld seam, exhibiting favorable formation quality. Microstructural analysis reveals that the weld seam consists of granular bainite and acicular ferrite. Tensile testing indicates that fracture occurs in the weld seam, with a tensile strength of 789 MPa.更多还原