Heat treatment method for austenitic stainless steel pie forgings for nuclear power reactor internals

Abstract

The invention discloses a heat treatment method for austenitic stainless steel pie forgings for nuclear power reactor internals. The method is used for performing heat treatment on a solid forging, the material of the solid forging is 0Cr19Ni10, the diameter of the material is not smaller than 4000 mm, and the thickness of the material is not smaller than 400 mm. The method comprises the following steps: step 1, heating the forging to 400-450 DEG C for preserving heat by using the maximum power of a heat treatment furnace, wherein the preserving heat time is 0.5-1 minute for each millimeter of forging thickness; step 2, heating the forging to 670-700 DEG C for preserving heat at the temperature rise rate of at most 50 DEG C / h, wherein the preserving heat time is 0.5-1 minute for each millimeter of forging thickness; step 3, heating the forging to 1040-1080 DEG C for preserving heat at the temperature rise rate of at most 150 DEG C / h, wherein the preserving heat time is 3-5 minutes for each millimeter of forging thickness; step 4, discharging the forging from the furnace and cooling with water. The crystalline grains of the 0Cr19Ni10 steel forging subjected to heat treatment by the method are not grown, organization is uniform, and the strength of room temperature and 350 DEG C of high temperature meets the design requirement of the nuclear power reactor internals.

Description

technical field [0001] The invention relates to a heat treatment method, in particular to a heat treatment method for an austenitic stainless steel pie-shaped forging used for nuclear power reactor internal components. Background technique [0002] With the rapid development of the economy, the demand for energy in various countries has increased dramatically. Because nuclear fuel can release efficient and clean energy, the development and utilization of nuclear energy has been promoted. Compared with other earlier reactor types, the AP1000 nuclear power stack has the characteristics of large-scale and integrated, and the size and weight of the internal components of the nuclear power main equipment are correspondingly larger. [0003] The reactor internals sit at the center of the reactor and provide support and compression for the nuclear fuel assembly, while also shielding the pressure vessel from the effects of radiation. The austenitic stainless steel pie-shaped forgi...

AI Technical Summary

Problems solved by technology

Practice has shown that if effective measures are not taken, the temperature difference between the bottom and side of the forging can reach hundreds of degrees during the simultaneous cooling process, resulting in poor performance at the bottom of the forging and worsening the uniformity of the forging performance

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