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20Mn2管材是汽车减震器活塞杆的理想材料。本文通过金相显微镜、扫描电镜、显微硬度计等分析手段研究了激光-电弧复合焊接20Mn2管材焊接接头的组织与性能。结果表明:在电弧电流一定的条件下(80 A),随着激光功率增大,焊缝熔深增大,焊缝熔宽变化不明显。随激光功率增大,焊缝晶粒逐渐粗大。在激光功率1300 W条件下,随着焊接电流增大,焊缝熔深增大,焊缝熔宽先增大后减小。随着焊接电流增大,焊缝的显微硬度峰值出现在焊缝区,随距离焊缝中心距离增大硬度逐渐降低。焊缝的主要组织为珠光体和铁素体,熔合区的主要组织为铁素体、珠光体、贝氏体和板条马氏体。
20Mn2 tubing is ideal for piston rods for automotive shock absorbers. In this paper, the microstructure and properties of 20Mn2 pipe welded joints by laser-arc hybrid welding were studied by means of metallographic microscope, scanning electron microscope and microhardness tester. The results show that with the increase of the laser power, the penetration depth of the weld increases and the weld width does not change obviously under the condition of constant arc current (80 A). With the increase of laser power, the weld grains gradually become coarse. Under the laser power of 1300 W, with the increase of welding current, the penetration depth of the weld increases, and the weld weld width first increases and then decreases. With the increase of welding current, the peak of microhardness of weld appeared in the weld zone, and the hardness decreased gradually with the distance from the center of weld. The main microstructure of weld is pearlite and ferrite. The main structure of weld zone is ferrite, pearlite, bainite and lath martensite.