Oxidation-Corrosion-Resistant Cast Iron Welding Alloy Nife-1

Cast iron welding rod is often used to solve the engine shell, cover body, machine base, casting teeth appear wheel fracture, crack, wear, tamping hole welding problems. Because of high carbon content, uneven structure, low strength and poor plasticity, cast iron electrode is a poor weldability material, which is easy to produce cracks during welding, it is difficult to cut. In order to achieve satisfactory results in welding and repair welding of cast iron, it is important to pay attention to“Three-part material and seven-part process”, not only to choose welding rod, but also to adopt suitable repair welding method.
The following welding process is recommended as a reference for cast iron welding and repair welding: 1, first remove the welding parts of sludge, sand, water, rust and other debris; In addition, the carbon-poor layer and oxide layer on the surface of iron castings working under High Temperature and steam environment for a long time should be removed. 2. According to the shape and defect type of the welded part, the preparation measures such as groove opening, crack preventing hole drilling and molten pool modeling are carried out. 3. For the parts that need cold welding, preheat them at 500-600 ° C, choose suitable current, continuous welding, keep the preheating temperature during the welding process, cover the insulating materials such as asbestos powder immediately after welding, and let them cool slowly, in order to improve its crack resistance and processing performance. 4. For cold welding work pieces, prevent the base metal melting too much, reduce the tendency of white, prevent too much heat concentration, resulting in excessive stress, small current, short arc and narrow pass welding should be used as far as possible (the length of each pass should not exceed 50mm) . Immediately after welding hammer weld to relax the stress to prevent cracking, until the temperature dropped to 60 degrees C below another weld. 5, pay attention to arc hole when closing, in order to prevent the closing arc crack.