Metrode CI-MET-NIFE description: The NiFe alloy is suitable for welding all grades of cast iron but particularly for spheroidal graphite (SG), nodular or ductile irons and some alloy cast irons. It provides compatible strength, ductility and toughness, coupled with good machinability. The NiFe consumables can also be used on some of the high alloy austenitic irons (Ni-Resist). The flake graphite grades are welded with a preheat of 300-350°C but the SG grades are best buttered using low heat input, and low temperature techniques to avoid HAZ hot cracking.