High manganese non-magnetic steel sheet excellent in stress corrosion cracking resistance and manufacturing method thereof

Abstract

The invention discloses a high-manganese non-magnetic steel plate with good stress corrosion cracking resistance and a manufacturing method thereof. According to a low-C high-Mn high-Cr low-Al and high-N alloying composition system, no precious alloy element Ni is added, the Austenite stabilization index (see the specification for the formula) is controlled, and the on-line quenching process is optimized. Hence, the microscopic structure of the finished product steel plate is made into a uniform and small austenite structure, the autstenitic grain size is larger than or equal to ASTM 6 levels, and the steel plate with high strength (tensile strength is larger than or equal to 800MPa), good non-magnetic performance (magnetic permeability is smaller than or equal to 1.0 micron) and good stress corrosion resistance (SCC crack depth is 0mm) can be obtained; and the method is particularly suitable for manufacturing electromagnetic shielding steel components.

Description

technical field [0001] The invention relates to a high-manganese nonmagnetic steel plate with excellent resistance to stress corrosion cracking (SCC) and a manufacturing method thereof. The steel plate has high strength (tensile strength ≥ 800MPA), excellent nonmagnetic (magnetic permeability ≤ 1.00μ), Stress corrosion cracking (SCC crack depth is 0mm, that is, no stress corrosion cracks occur on any corroded section of the steel plate) and other characteristics. Background technique [0002] As we all know, compared with SUS304 series stainless steel, high manganese non-magnetic steel plate is cheap (does not contain precious alloy element Ni), high strength and stable non-magnetic properties of steel plate in various cold and hot processing processes, so it is widely used in large quantities ; With the rapid development of my country's equipment manufacturing industry in recent years, the manufacturing volume and types of various key non-magnetic steel components are expand...

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Problems solved by technology

[0004] More importantly, there is a significant gap between the corrosion resistance of high manganese non-magnetic steel plates and austenitic stainless steel, especially in the neutral aqueous solution environment under the condition of tensile stress, the stress corrosion resistance of steel components (ie SCC) It is very poor, and it is easy to produce excellent corrosion cracks along the austenite grain boundary during use, which leads to the failure of steel components (Werkstoffeu. Palo Alto, Sept.14-17; "Anti-corrosion Technology", 21, 157(1972))

[0005] At present, high manganese non-magnetic steel components are all used by surface coating, but the surface coating process is complicated, the manufacturing cost is high, and the environment is polluted. More importantly, the surface coating has poor durability and requires regular coating maintenance. The parts that cannot be maintained are prone to stress corrosion in a short period of time, resulting in the scrapping of steel components, which affects the operating efficiency and life of the equipment; the development of high-manganese non-magnetic steel plates with corrosion resistance and SCC resistance equivalent to austenitic stainless steel plates has been without delay

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