Design method for 9Ni large forge piece construction forming

Abstract

The invention belongs to the field of forging, in particular to a design method for 9Ni large forge piece construction forming. The design method is suitable for large-section forge piece forming andimproving quality reliability of a large force piece and is used for solving the problems of center hole shrinkage, loosening and other problems hard to control in a traditional large forge piece manufacturing technology. The design method comprises the technologies of smelting, continuous casting blank surface washing and milling, vacuum packaging, high-temperature heating, high-pressure forgingand welding, forging and forming and the like. The metal traceless construction thought is adopted, a plurality of pieces of homogenized base metal are subjected to large deformation at the high temperature after being subjected to surface cleaning and vacuum packaging, metal solid connection is achieved, and an interface is sufficiently closed up. The core thought is breaking the whole into partsand making large from small, the large component homogenizing preparing technology is changed, the component breaking limit is broken through, and the quality reliability of a large forge piece is enhanced.

Description

technical field [0001] The invention belongs to the field of forging, specifically a design method for constructing and forming a 9Ni large forging, which is suitable for forming large cross-section forgings and improving the quality and reliability of large forgings. Background technique [0002] 9Ni steel is usually used in the design of the main shaft material, which is mainly used in liquefied petroleum and natural gas storage tanks in the form of steel plates, and is rarely used in forgings. However, to prepare a large forging with a net weight of 35 tons and a maximum section of the forging of 1600 mm requires 100 to 120 tons of steel ingots, which is extremely difficult in metallurgy. The main problems are: [0003] 1) It is difficult to prepare steel ingots. The solid-liquid two-phase region of 9Ni steel is wide, and the viscosity of molten steel is high, which is easy to form shrinkage cavities; at the same time, martensitic transformation occurs during the cooling...

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Problems solved by technology

[0019] The purpose of the present invention is to provide a simple and efficient design method for the construction and forming of 9Ni large forgings, to solve the serious problems such as the extremely difficult guarantee of the internal metallurgical quality of the steel ingots manufactured by the traditional process, macro segregation, loose center and coarse grains, etc. and economically less expensive

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