The method of cast iron welding with excessive carbon oxidation

Abstract

The aim is to improve the quality of the weld metal during arc welding of cast iron. The
developed method for welding cast iron by electric arc, characterized in that the pre-melt surface
decarburization conducted cutting hematite.
The study was carried out at the cold welding of cast iron steel welding electrodes at a
constant current of reverse polarity. Previously performed decarbonization cutting oxygen, which is
released as a result of thermal dissociation of hematite (Fe2O3) at temperatures above 700 °C. Cast
iron cutting in place of hematite coated with a flux paste, mixed with the aqueous solution of КMC
glue. After drying the layer of hematite is melted carbon electrode to direct polarity. As the melt
oxidation of hematite and carbon in the molten metal to a depth of 3-5 mm along the carbon
electrode is moved across the cutting surface decarburization. Decarbonization of cast iron cutting
surface includes a decrease in the carbon content of the remelted metal layer at a depth of 3-5 mm
to 90-95 %. Welding is carried out without preheating. Weld metal structure Troost-sorbitol and
small inclusions of ferrite. Near the surface – a typical structure for a cast mild steel.