Blowing effect

The magnetic blowing effect is an effect that occurs in arc welding . The arc is deflected as a result of changes in the density of the inherent magnetic field.

Development of the blowing effect

Blowing effect of the arc through welding on the edge of the workpiece and with different connections of the power supply

Every conductor through which current flows is surrounded by a magnetic field. So do the electrode, the arc and the workpiece. If the magnetic field is disturbed in its symmetry, i. H. the field line density is unequal, the arc is deflected into areas of lower magnetic flux density. The disturbance of the field line symmetry can be caused by the arrangement of the power connection or by the mass distribution of the ferromagnetic workpiece . The deflection of the arc caused it to lengthen, increasing mobility and instability.

Effect of the blowing action

The blowing effect is most pronounced when welding ferromagnetic materials with direct current. When welding with alternating current, the blowing effect is greatly reduced.

The quality of the seam can be impaired by the blowing effect. With the blowing effect, the formation of pores in the weld metal also increases, as more gases from the air are whirled into the arc. In addition, binding errors can occur. The formation of the seam surface is disturbed. Quality-reducing undercuts can occur.

credentials

1. ↑ M. Schellhase: The welding arc as a technological tool. Verlag Technik, Berlin 1985, ISBN 3-87155-100-7 , pp. 184ff.