双尖角磁场再压缩等离子弧中板焊接

WELDING OF MEDIUM PLATE BY THE PLASMA ARC RE-CONSTRICTED WITH A DUAL-CUSP MAGNETIC FIELD

本文从电弧热源特征及熔池受力分析两方面说明,采用双尖角磁场再压缩等离子弧沿电弧截面长径方向施焊是提高小孔型焊接一次焊双面成形厚度极限的有效途径,介绍了采用此方法在实际生产条件下对16mm不锈钢板焊接的试验结果,并就其工艺特点、焊缝成形规律以及工艺参数的影响进行了探讨。由于双尖角磁场再压缩等离子弧随焊接厚度增加无需大幅度增加焊接电流以保证穿孔,可以通过调节激磁电流来提高等离子弧的穿透能力.因而熔池尺寸和小孔孔径均受到限制,有利于维持熔池液态金属的力学平衡,故焊接厚度极限和焊缝成形的稳定性都比一般等离子弧有明显提高.

A new technique of PAW is presented on the basis of investigation on the features of welding heat source and the mechanical condition of the molten pool, This new technique is characterized by using a dual-cusp magnetic field to make the plasma are flat and welding along the major axis of the cross section of are. The most valuable advantage of this method lies in the allowance of increasing the metal thickness for dual-sided formation by a single pass. This paper introduces the experimental results of welding 16mm thick stainless steel by this method under a real production condition. The technological characteristics of this technique and the pattern of the weld formation as well as the influencs of different parameters are discussed. Because the holing ability of plasma, by adopting this method, can be strengthened by increasing the field current, it is unnecessary to make a substantial increase of welding current for increased metal thickness. As a result, the sizes of the pool and the keyhole are restricted, So it is much easier to maintain the liquid metal in mechanical equilibrium