The method of semi-automatic welding of cast iron with the oxidation of excess carbon

Abstract

The aim is to improve the quality of the weld metal during arc welding of cast iron.
This is achieved in that the arc between a carbon electrode and the workpiece, and the
welding wire is fed through a hole in the carbon electrode, which feeds direct current polarity in a
gas burner nozzle fed oxygen.
This carbon electrode is also the current supply to the welding wire and a substance which
forms carbon dioxide gas in the arc when welding with straight polarity.
Carbon dioxide performs protect the weld pool from the atmosphere and serves as an
additional carbon oxidizer that enters into the weld metal from the main bath - iron.
Welding is carried out without preheating. During welding, controlled temperature in the
base metal heat affected zone, preventing heating of the workpiece is above 70 °C. As a result of
investigations since the welds, cracking and other defects in welds and heat-affected zone is not
detected. The hardness of the weld metal does not exceed 210-230 HB and allows machining of
welds conventional metal-cutting tools.