Welding repair method for local defect of crankshaft for ship

Abstract

Disclosed is a welding repair method for a local defect of a crankshaft for a ship. The crankshaft is made of S34MnV. The welding repair method is characterized in that preheating before welding is not conducted, and the local defect on the surface of the crankshaft is repaired through a cold welding method; and the welding repair method comprises the steps that polishing treatment is conducted on the defect on the surface of the crankshaft before welding, then a priming coat is formed through argon arc welding, then CO2 gas shielded welding is adopted for welding of a filling covering layer, and finally grinding and polishing are conducted on the repaired surface. According to the welding repair method, the tedious processes of preheating before welding, and heat preservation and slow cooling after welding are avoided, repair cost is reduced, meanwhile, the welding repair method has the advantages that the processes are simple, operability is high, and work efficiency is high and can be used for repair and maintenance of the local defect of the crankshaft for the ship, and very high practicability is achieved.

Description

technical field [0001] The invention relates to a repair process for marine diesel engine parts, in particular to a welding repair method for local defects of a marine crankshaft, which belongs to the field of welding technology. Background technique [0002] As the core component of the engine, the crankshaft is mainly responsible for power transmission and is one of the important moving parts during the operation of the engine. In the high-power marine low-speed diesel engine, the marine crankshaft is a large-scale processed forging with large size and high quality. Some of them are more than ten meters long and hundreds of tons in weight. The cost accounts for about 20% of the total cost of the diesel engine. Marine crankshafts occasionally have defects such as local bruises and wear during transportation and installation. Due to the high cost, once such problems occur, partial repair measures are generally taken for the crankshaft. The traditional repair method mainly a...

AI Technical Summary

Problems solved by technology

However, supersonic spraying has high requirements on the surface condition of equipment and products, and at the same time, the repair cost is also high, which is not conducive to improving economic benefits

There is also a repair method for marine crankshafts that uses welding methods, but generally requires preheating before welding and heat preservation and slow cooling after welding, so the efficiency is low and the operation is difficult

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