中厚板脉冲双丝高速打底焊自由成形及稳定性分析

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中图分类号：TG444

Abstract：The 12 mm thick Q235 steel eutectic pool backing welding is realized by using tandem welding torches matched with diferent DC pulse frequencies.High-speed image（HSI）andreal-time electrical signals are used to monitor the welding process inreal time.The effects of welding speed on weld formation，arc morphology and welding process stability are studied.The results show that the welding speed mainly affects the weld forming and welding process stability，but has litle influence on the arc morphology.With the increaseof welding speed，the arc stability increases first and then decreases. When the welding speed reaches 40mm/s ，the best back free forming is achieved.At diferent welding speeds，the leading wire arc maintains a high stifess and hardly deviates. The trailing wire arc forms a regular swing of 9°-15° in a single pulse cycle，which promotes themetal inthe middleofthe molten pool to move tothe side.The molten flowreduces the metal accumulationattherear of the molten pool，thereby eliminating humpand ridge defectson the weld surface and improvingtheoverallfinish.The welding stabilityof the leading wire is generally higherthan thatof the trailing wire. When the welding speed is 40mm/s ，the stability of the arcs is the best.

Key words： tandem; pulse； backing welding； free forming；welding stability

0前言

当前中厚板焊接领域对焊接生产效率提出了越来越高的要求，增加焊丝数量和提高焊接速度都是提高焊接生产效率的有效方法[1-2]。（剩余7037字）