耐候钢Q450NQR1深熔GMAW电弧行为

分别采用深熔GMAW和脉冲MAG对耐候钢Q450NQR1进行了焊接试验,焊接过程中采集电流、电压及其对应的电弧图像,观察和分析了电弧形态和焊缝成型,同时基于图像处理考察了深熔GMAW焊接电流和焊接速度对电弧行为、焊缝成型的影响.结果表明:相比脉冲MAG,深熔GMAW电弧能量更集中,热源位置下降,焊缝熔深增加,且焊缝几何对称性较好;随着深熔GMAW焊接电流的增加和焊接速度的降低,电弧面积减小,边缘周长变短,质心位置下降,焊缝熔透深度增加;焊接电流315 A、焊接速度650 mm/min时焊接电弧最为稳定,焊缝成型质量也最好.采用优化的焊接工艺完成了12 mm厚Q450NQR1钢板材的单面焊双面成型,焊缝成型较好,接头各区域无软化和脆化现象.

Arc behavior of deep penetration GMAW of weathering steel Q450NQR1

The weathering steel Q450NQR1 was welded separately by using the deep penetration GMAW and pulse MAG. The welding current, voltage and the corresponding arc image during the welding was collected. The relationship between the dynamic behavior of the welding arc and the weld formation was analyzed by processing arc image. At the same time, the influence of the different welding current and welding speed under the deep penetration GMAW on the arc behavior and the weld formation was researched. The results showed that compared with pulsed MAG, deep penetration GMAW has more concentrated arc energy, lower heat source position, increased weld penetration, and good weld geometric symmetry; during deep penetration welding, as the welding current increases and the welding speed decreases, the arc area decreases, the arc edge perimeter becomes shorter, the arc centroid position drops, and the penetration depth of the weld increases; When the welding current is 315 A and welding speed is 650 mm/min, the welding arc is the most stable, and the weld seam forming quality is also the best. The single-side welding and double-side forming ofQ450NQR1 steel sheet with 12 mm thickness is completed by the optimized welding process, the weld is well formed, and there is no softening and embrittlement in each area of the joints.