Nickel 55 Cast Iron Repair 3/32" Stick Electrode ENiFe-CI Nickel 55 Rod 2Ib PackENiFe-CI Nickel 55 welding electrode is designed for welding gray iron castings to themselves as well as joining them to mild steel. It can also be used to repair castings. The welds are moderately hard and require carbide tipped tools for post weld machining. A preheat and interpass temperature of not less than 350⁰F is recommended during welding.