Method of the plasma jet remelting of a surface layer of a flat metal work having parallel side edges and apparatus for carrying out the method

The method consists in that a flat work in an initial position is oriented horizontally between cooled mold beams. Plasma torches are arranged in line across the parallel side edges so that the anode spots of the extreme torches are confined by said edges of the work. By supplying a plasma forming gas and electric current to the plasma torches the work is heated with the formation of a metal pool which extends across the work from edge to edge. By relatively moving the work and the plasma torches in a horizontal plane and along the edges of the work movement of the metal pool over the surface thereof is effected and thereby a remelted layer as thick as the pool is deep, is obtained. The apparatus for carrying out the method comprises a sealed chamber containing a mold having two beams arranged in a horizontal plane and being parallel to one another. Installed in the chamber are plasma torches mounted on shafts and connected through supply lines with the sources of plasma forming gas, electric current and cooling water. Each of the shafts is journalled in a sealing bush installed in the wall of the sealed chamber so that the axis of the shaft is parallel to the beams. Each shaft is rotatively driven by a drive. The apparatus further comprises a drive for relatively moving the work and the shafts in the plane parallel to the beams, connected with at least one of the elements taking part in such movement. The practice of the method with the help of the apparatus of the invention permits a high-quality work of a predetermined macrostructure of a surface layer, to be produced at a higher rate of treatment.