Process design method of upper casting for large ship

Abstract

The invention discloses a process design method of an upper casting for a large ship, which is formed by optimizing on the basis of an existing process. The process design method comprises the following steps that (1), the linear shrinkage is selected as 1.8%-2.0%; (2), cutter leveling is additionally carried out a rib plate of a welding steel plate making contact with a ship body; (3), a processcorrection amount is added to the rib plate; (4), an air exhaust steel pipe is horizontally placed in the middle of a loam core, straw ropes are wound outside peripheral cutting holes, and a wood realsample is subjected to pattern draft according to a ratio of 1:20; (5), a riser is designed by adopting a hot pitch circle method, and spot casting is carried out at the riser; (6), upper and lower middle surfaces are selected as parting surfaces; (7), sand-hanging external chill is horizontally placed on the back surface of the riser; and (8), proper wrapping holes and quantity are selected according to gross weight and maximum height of the casting. By the adoption of the process design method, the casting quality of the upper casting can be guaranteed, the using requirement of a shipyard is met, meanwhile, the production efficiency is improved, the production cost is reduced, and the process design method is suitable for lower castings, upper and lower rudder knobs, rudder stock bearings and dumb braces.

Description

technical field [0001] The invention belongs to the technical field of cast steel, in particular to a process design method for upper castings of large ships. Background technique [0002] Casting molding is an important production method of equipment component blanks, the basis of manufacturing industry, and represents the level of a country's basic equipment industry. Large-scale marine castings are characterized by large outline size, complex curved surface shape, large wall thickness variation, easy deformation during casting, and difficult control of dimensional accuracy. [0003] my country's annual export volume of marine steel castings ranks first in the world, but there is still a big gap compared with developed countries in terms of overall technical level, mainly in poor serviceability, low process yield and high repair rate, and the price Also relatively cheap. [0004] In the downturn of the foundry environment, foundry enterprises are facing fierce competition...

AI Technical Summary

Problems solved by technology

[0005] At present, domestic marine steel castings mainly have many defects and a large repair rate

Especially the shaft hole, the position of the shaft hole is the most important part of the marine castings, but there are often problems in this area in the current industry. The position of the shaft hole is caused by air holes and cracks due to poor exhaust. Not only is it difficult to repair here, but also the position of the shaft hole Repair welding is usually not allowed

Due to the deformation of the ribs, repeated repairs and cleanings not only affect the construction period, but also increase the cost

[0006] The technical problems to be solved in the present invention are as follows: air holes and cracks are generated at the position of the shaft hole due to poor exhaust; deformation of the rib plate causes the joint between the rib plate of the casting and the steel plate of the hull to fail; casting defect

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