METHOD AND DEVICE FOR INVERTED HIDDEN-ARC WELDING

摘要

A method for inverted hidden-arc welding provides for feeding to the joint to be welded, from below, a flux under variable pressure at different points along said joint, a consumable electrode (5) being fed from below through said flux and the arc being ignited so that a welding bath (6) of a liquid slag is formed. The welding process is carried out by feeding the flux (3) in the area (A) upstream of the arc in relation to the joint (8) under a preset constant pressure necessary for creation of pressure conditions of the welding bath (6), whereas along the area (B) of arc discharge and of the location of the welding bath (6) the pressure is applied through a layer of the flux (3) and the liquid slag, the main quantity of the flux (3) being fed under pressure to the zone of the welding bath (6) and the pressure being gradually increased so that its maximum value is distributed at the beginning of crystallization zone of the weld joint (8) and maintained at that level along the whole crystallization zone. Then the crystallization and forming of the weld joint is carried out. A device for implementing the method is also proposed. The invention may be used to weld longitudinal and turning annular joints.