Semi-closed tool for forging hollow nuclear power main pipe

Abstract

The invention discloses a semi-closed tool for forging a hollow nuclear power main pipe, which comprises a mandrel. Two retainer rings are disposed on the mandrel, the nuclear power main pipe is sandwiched between the two retainer rings, positioning structures which are used for positioning the two retainer rings are disposed among the outer sides of the two retainer rings and the mandrel, and at least one end of the mandrel is provided with a prism section. The tool can be used for forging an inner hole of the nuclear power main pipe via an integral hollow forging forming process by the aid of a hollow steel ingot, can be effectively used for forging the nuclear power main pipe, can lead the wall of the nuclear power main pipe to deform uniformly, and achieves effects of refining grains, improving structures and promoting uniformity of metal flowing ingredients, so that a fine forging structure is obtained.

Description

technical field [0001] The invention relates to a special tool assembly for free forging, in particular to a semi-closed tool for forging a hollow nuclear power main pipeline. Background technique [0002] At present, the basic forging forming method for developing the third-generation nuclear power AP1000 main pipeline forgings at home and abroad is to use a solid steel ingot through upsetting→drawing→upsetting→drawing→shoulder pressing→forging nozzles, pipe body→trimming . This forging method uses two times of upsetting and elongation before forming the nozzle and pipe body. The purpose is to fully deform and forge the billet before forming, so as to improve the process of pouring or remelting crystallization of the steel ingot. Inherent defects such as segregation and porosity generated in the However, the above-mentioned process requires a long heating time, and requires an extra-large forging press to complete the above-mentioned processing. Because solid forging is ...

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Problems solved by technology

However, the above-mentioned process requires a long heating time and requires an extra-large forging press to complete the above-mentioned processing

Because solid forging is used, the inner hole of the main pipe φ786 is not forged, so in the subsequent processing process, not only the expensive raw materials are greatly wasted, but also the 20-ton heavy pipe is completely machined and deep-drilled. The material of the inner hole is processed, and a lot of processing time is increased, which greatly prolongs the manufacturing cycle and greatly increases the manufacturing cost of the pipe fittings

Due to the limitation of the capacity and cost of the electroslag remelting furnace, the cross-sectional size of the hollow steel ingot cannot meet the requirements of process deformation and forging ratio

If the cross-sectional size of the hollow steel ingot is increased by the method of pier thickening, the process is very complicated, and extra-large forging equipment is required to complete the whole process

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