Large-sized iron casting fracture arc cold-welding repair method

Abstract

The invention provides a cold welding fracture recovery method for a large-scale cast iron piece. Non cast iron welding material is selected, a layer of metal is scraped off on the fracture surface along the crack direction, so as to form a V-shaped groove; steel screws are screwed in the two sides of the groove, and a direct current welder is used for multi-layer welding. The technique of the invention carries out welding repair to the fracture of the large-scale cast iron piece under the condition of not being influenced by climate, the technique is simple, and the welding effect is good.

Description

Technical field: [0001] The invention relates to a method for welding and repairing fractures of large iron castings, belonging to the technical field of metal material welding. Background technique: [0002] Cast iron is a difficult-to-weld material. Although there are many welding methods for iron castings, semi-heat welding is usually used for repairing the fracture of large iron castings: that is, preheating the parts to be welded to 400°C before welding. Then carry out welding, and then carry out heat preservation and slow cooling after welding. However, this welding method is sometimes limited by environmental conditions and cannot be carried out. For example, in cold seasons or alpine regions, without special heating and insulation facilities, the preheating temperature is unstable and uneven, and it cannot be done after welding. Slow cooling will cause white structure in the welded joint, cracks in the weld seam and heat-affected zone, and the entire weld seam will ...

AI Technical Summary

Problems solved by technology

However, this welding method is sometimes limited by environmental conditions and cannot be carried out. For example, in cold seasons or alpine regions, without special heating and insulation facilities, the preheating temperature is unstable and uneven, and it cannot be done after welding. Slow cooling, resulting in white structure of welded joints, cracks in weld seam and heat-affected zone, and the entire weld seam will be peeled off from the base metal, resulting in welding failure

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