Method for welding outer rib plates in base of lower reactor core vessel of high-temperature gas-cooled reactor

Abstract

The invention discloses a method for welding outer rib plates in a base of a lower reactor core vessel of a high-temperature gas-cooled reactor. With the method, the maximum deformation of a bottom plate can be controlled to be smaller than or equal to 9.6 mm. After an outer barrel and the bottom plate are welded and the 15 outer rib plates are evenly distributed between the bottom plate and the outer barrel, to-be-welded parts are preheated to be at 205 DEG C or higher, positioned welding is performed on the outer barrel and the outer rib plates as well as the bottom plate and the outer rib plates after preheating, and then the outer rib plates and the bottom plate are welded after the outer rib plates and the outer barrel are welded firstly with a multilayer multi-pass welding method. The method has the advantages as follows: with the method, the maximum deformation of the bottom plate can be controlled to be smaller than or equal to 9.6 mm, firm welding can be realized, welding quality requirements in the aspect of nuclear power can be met, and the service life of the base is prolonged.

Description

technical field [0001] The invention relates to a method for welding outer rib plates in the base of the lower core shell in a high-temperature gas-cooled reactor. Background technique [0002] With the introduction of the "fourth generation advanced nuclear energy system" concept, high temperature gas-cooled reactors are gradually characterized by their unique safety, wide range of uses, miniaturization, low investment, and short construction period following the introduction of the concept of modular high temperature reactors. And other characteristics have won the favor of more and more people of insight. [0003] The high-temperature gas-cooled reactor is an advanced reactor with the safety characteristics of the fourth-generation nuclear energy system. It is one of the six alternative reactor types in the fourth-generation nuclear energy system in the international nuclear energy field, and it is the only one that can achieve commercial operation before 2020. Generatio...

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Problems solved by technology

[0009] The material of the base workpiece is 12Cr2Mo1R. Due to the high content of Cr and Mo in the material, there is a greater tendency to harden during welding, and the welding is very difficult.

The maximum deformation of the bottom plate should be controlled at ≤9.6mm, that is to say, within the processing allowance. The current conventional welding method cannot guarantee that the maximum deformation of the bottom plate is controlled at ≤9.6mm

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