How To Weld Gray Cast Iron. The cold in cast iron cold welding refers to the low heat needed to the base metal. A fusion weld made in nodular iron may not cause loss of tensile strength but will almost always reduce the shock resistance of the part.
It is best to consider these tips if you plan to use your MIG to weld cast iron. Probably the most critical parts of welding cast irons. A low amperage is needed to avoid deep fusion between the base material and filler.
Cast Iron Cold Welding Steps.
How to weld cast iron with a MIG welder To maintain a nice weld use the MIG welder to maintain the lowest feed rate and the lowest current. Keep the casting temperature up to 100 degrees F. Its a good option to minimize the extreme heating and cooling of the electric welding processes and its easier to maintain the temperatures of the components with it. All gray irons have almost no ductility again because of the flake form of the graphite which causes the metal to break before any appreciable amount of permanent elongation has occurred.