Cast iron electrode due to the high carbon content, and inhomogeneity, low intensity, the plastic is extremely poor and belong to the weldability of materials, welding process is apt to crack; the cooling rate after welding fast, easy to produce white tissue, resulting in the difficulty of cutting . Welding and repair welding of cast iron, to achieve more satisfactory results, you must pay attention to the third of material, the seventh of the process, not only to select the electrode, and a suitable welding method is particularly important. Recommended the following welding processes, as the cast iron welding and repair welding of reference: 1, first clear the welded parts of clay, sand, water, rust and other dirt; a long period of high temperature steam environment, iron castings, but also to remove the surface carbon-poor layer and the oxide layer. 2, cast iron Welding Rod according to the shape of the welded parts, defect type, and the groove, playing only the hole and weld pool shape, and other preparedness measures. Need cold welding of the workpiece, the first warm-up about 500-600 ℃, the choice of the appropriate current, continuous welding, the welding process, always preheat temperature, immediately after welding to cover asbestos powder insulation material, allowed slow cooling to improve the crack resistance and processing properties. For cold welding workpiece, to prevent the base metal to melt too much, reduce the chilling tendency, to prevent excessive heat concentrated, resulting in excessive stress, should be adopted in the small current, short-arc, Welding Electrodes the length of the narrow path welding (each bead is generally not more than 50mm). Relaxation stress hammering the weld immediately after welding to prevent cracking, cast iron electrode when the temperature dropped to below 60 ℃ and then welding a. 5, Crater Note crater filled to prevent closing the arc at the crack.