PROPERTIES OF WELDED JOINTS IN LOW-CARBON AND LOW-ALLOY STEELS PRODUCED BY CO2 PLASMA WELDING.

In CO//2 plasma welding with filler wire, the high losses of deoxidizing elements may cause the formation, on the surface of the weld metal, of a slag with a high content of iron oxides which impairs the separability of the slag crust. The main losses of alloying elements in CO//2 plasma welding occur in the droplet formation stage. In comparison with consumable electrode welding, the role of the pool stage is considerably more important. To produce sound alloyed welded joints, welding should be carried out at a speed of more than 30 m/hr at a ratio of the plasma arc current to the cross-sectional area of the shaping nozzle of less than 8 multiplied by 10**6 A/m**2, and the filler wire should be fed in the directions in which its melting takes place in the pool within the limits of the current-conducting channel of the arc column.