Austenitic stainless steel

Abstract

The invention relates to austenitic stainless steel which is high in low temperature strength, low temperature toughness and low temperature non-magnetism as well as better in neutron irradiation resistance, can be used in a magnet support structure of a nuclear fusion reactor, and comprises the components by mass percent: 16.00-22.0% of Cr, 8.00-12.00% of Ni, 1.00-3.00% of Mo, 0.06-0.25% of N, 0.010-0.040% of C, 1.00-4.00% of Mn, less than or equal to 1.00% of Si, 0.01-0.10% of Nb, 0.01-0.10% of Ta, 0.030-0.10% of Co, less than or equal to 0.03% of P, less than or equal to 0.005% of S, 0.0005-0.0018% of B, and the balance of Fe and unavoidable impurities; and furthermore, the value of Val (Cr-Ni) is less than 20.5, and Val (Cr-Ni)= 3* (Cr+Mo)+4.5*Si-2.8*Ni-1.4*Mn-84*(C+N).

Description

technical field [0001] The austenitic stainless steel of the present invention, in particular, relates to an austenitic stainless steel that can be used for the support structure of nuclear fusion reactor magnets, which has high low-temperature strength, low-temperature toughness, low-temperature non-magnetism and good resistance to neutron radiation performance. Background technique [0002] The nuclear reactors currently used mainly obtain energy through nuclear fission reactions. While obtaining energy, there are also potential dangers such as nuclear leakage. In addition, the storage of uranium resources for fission reactions is also very limited, which will restrict this type of nuclear power reactors to a certain extent. mass construction. With the advancement of technology, fission reaction to extract deuterium and tritium from seawater to obtain energy has gradually entered the research field, and the world has also begun to conduct tentative research on nuclear fis...

AI Technical Summary

Problems solved by technology

However, the current general-purpose 304L austenitic stainless steel cannot meet the non-magnetic and low-temperature performance requirements of the nuclear reactor magnet support structure due to its metastable austenitic structure, while the 316L austenitic stainless steel has a stable austenitic structure. However, due to the small amount of ferrite structure, it has certain magnetic properties, and the low carbon content results in insufficient strength.

[0004] At present, there are many patents related to low-temperature austenitic stainless steel, mainly related to low-temperature marine austenitic stainless steel, such as US4675156 and JP 60-9862, which increase the solid solubility of nitrogen by providing chromium and manganese content. Obtain high low-temperature yield strength and good low-temperature impact toughness, but it also increases the difficulty of production while increasing the strength, such as difficult to control inclusions in the smelting process, poor thermoplasticity, and because it does not contain molybdenum, it is resistant to pitting corrosion The performance is also poor; although JP 2-97649 has obtained low-temperature high-strength austenitic stainless steel through thermal processing adjustment, but the content of niobium is high, the neutron radiation resistance of the material cannot be guaranteed, and its composition cannot be guaranteed Its non-magnetic properties; US4568387 replaces part of the nickel element by increasing the manganese content and nitrogen content, but it is a metastable austenitic stainless steel, which cannot meet the non-magnetic requirements; Improve low-temperature strength, but cannot guarantee good anti-neutron radiation performance and non-magnetic performance

[0005] It can be seen that the austenitic stainless steel provided in the prior art cannot have both high low-temperature strength, low-temperature toughness, low-temperature non-magnetism and good neutron radiation resistance, so it cannot meet the requirements of the nuclear fusion reactor magnet support structure. Require

Images