Crystalline grain control method for GH690 alloy shear cover of explosion valve

Abstract

The invention discloses a crystalline grain control method for a GH690 alloy shear cover of an explosion valve and belongs to the technical field of material machining. The method aims to solve the problems that the structure of a forge piece of the GH690 alloy material shear cover of the explosion valve is not even, and crystalline grains abnormally grow up. A heat treatment machining is organically combined with a forging machining, and the machining method that large deformation free forging is implemented at a high temperature (1020 DEG C to 1150 DEG C), small deformation foetal die forging is implemented at a medium temperature (710 DEG C to 850 DEG C), and the inhibition function of carbide second-phase particles on moving of a grain boundary is used for restraining the abnormal growth of the crystalline grains in forging machining of the shear cover in an auxiliary mode is provided. According to the crystalline grain control method for the GH690 alloy shear cover of the explosion valve, the forging piece forming and crystalline grain refinement are conducted synchronously, and the shear cover forge piece is obtained through heating twice; the machining limitation that a forging piece with the simple structure is subjected to high-temperature multiple-time hierarchical forging machining at present is overcome; the forging heating number is reduced; the follow-up heating treatment of the forging piece of the GH690 nickel-based alloy sheer cover is avoided. The structure with even carbides and refined crystalline grains of the GH690 alloy shear cover of the explosion valve forged through the method can be obtained.

Description

technical field [0001] The invention relates to a grain control method for a GH690 alloy shear cover of a blasting valve, belonging to the technical field of material processing. Background technique [0002] As a special valve, the burst valve was introduced for the first time in the new generation of pressurized water reactor nuclear power plants. It is mainly used in the automatic pressure relief system, low pressure safety injection system and containment recirculation system. In the event of a serious accident, it is triggered by opening the valve signal In the blasting unit, the high-pressure gas generated pushes the piston in the valve, cuts off the blind pipe of the valve diameter, that is, cuts off the shear cover, and the cooling water can enter the core for cooling, preventing the nuclear reactor from continuing to operate, thereby maximizing the efficiency of the nuclear power plant. security. figure 1 It is a schematic diagram of the opening principle of th...

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Problems solved by technology

[0006] The invention proposes a grain control method for the GH690 alloy shear cover of the blasting valve, aiming to solve the problems of uneven structure and abnormal grain growth of the GH690 alloy shear cover forging of the blasting valve.

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