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CN-122013043-A - 400 MPa-grade high-manganese high-ductility non-magnetic vibration-resistant steel bar and production method thereof

CN122013043ACN 122013043 ACN122013043 ACN 122013043ACN-122013043-A

Abstract

The invention provides a 400 MPa-grade high-manganese high-ductility non-magnetic vibration-resistant steel bar and a production method thereof, wherein the balance of Fe and other unavoidable impurities are C0.25%-0.35%、Si0.50%-0.70%、Mn15.0%-24.0%、V0.2%-0.4%、Nb0.01%-0.03%、Als0.01%-0.04%、N 0.20-0.60%、P≤0.015%、S≤0.005%、H≤0.0002%,, and the A value=33C% +0.1Mn% +18N% is more than or equal to 16, and the B value=33C% -Mn% -10. Compared with the prior art, the invention improves the stability of the austenite structure through component design and production control, and in the reinforced concrete structure under the strong magnetic field environment, powder spraying treatment is not needed, so that the normal use of the concrete structure under the strong magnetic environment is realized, and creep does not occur.

Inventors

  • YANG YINGDONG
  • GUO ZHAN
  • ZHAO XU
  • CHEN FEI
  • CHEN PENGFEI
  • WANG LONGLONG

Assignees

  • 马鞍山钢铁有限公司

Dates

Publication Date
20260512
Application Date
20260225

Claims (10)

  1. 1. The 400 MPa-grade high-manganese high-ductility non-magnetic vibration-resistant steel bar is characterized by comprising the following components in percentage by mass: C 0.25%-0.35%、Si 0.50%-0.70%、Mn 15.0%-24.0%、V 0.2%-0.4%、Nb 0.01%-0.03%、Als 0.01%-0.04%、N 0.20-0.60%、P≤0.015%、S≤0.005%, The balance of Fe and other unavoidable impurities.
  2. 2. The 400 MPa-grade high-manganese high-ductility nonmagnetic vibration-resistant steel according to claim 1, wherein the composition of the 400 MPa-grade high-manganese high-ductility nonmagnetic vibration-resistant steel satisfies a value of a=33×c% +0.1×mn% +18×n%. Gtoreq.16 and a value of b=33×c% -Mn%. Ltoreq.10.
  3. 3. The 400 MPa-grade high-manganese high-ductility nonmagnetic vibration-resistant steel bar according to claim 1 or 2, wherein the microstructure of the 400 MPa-grade high-manganese high-ductility nonmagnetic vibration-resistant steel bar is austenite at normal temperature, and the austenite ratio is not less than 99.90%.
  4. 4. The 400 MPa-grade high-manganese high-ductility non-magnetic vibration-resistant steel bar according to any one of claims 1 to 3, wherein the 400 MPa-grade high-manganese high-ductility non-magnetic vibration-resistant steel bar has normal-temperature mechanical properties of yield strength R eL is more than or equal to 400MPa, tensile strength R m is more than or equal to 800MPa, strength-to-flex ratio R m /R eL ≥1.80,R eL /R eL 0 is less than or equal to 1.30, elongation after breaking A is more than or equal to 40.0%, maximum force total elongation A gt is more than or equal to 35.0%, residual magnetism is less than or equal to 0.5nT before and after processing of the steel bar, and relative magnetic permeability is less than or equal to 1.05.
  5. 5. A method for producing the 400 MPa-level high-manganese high-ductility non-magnetic vibration-resistant steel bar according to any one of claims 1 to 4, wherein the production method comprises the following process flows: Batching, converter smelting, LF refining, billet continuous casting, heating, bar rolling, controlled cooling, steel bar finished product bundling and warehousing.
  6. 6. The production method according to claim 5, wherein the converter smelting is performed at a converter endpoint C of 0.10% or less and at a point P of 0.010% or less, and the endpoint temperature is controlled to be above 1700 ℃.
  7. 7. The production method of the steel ladle according to claim 5, wherein the LF refining is characterized in that the steel ladle after steel tapping is subjected to heating refining treatment in an LF furnace, nitrogen is blown to the bottom of the whole ladle, the nitrogen flow is based on the condition that the steel ladle is not splashed by the steel ladle, premelted refining slag and lime are added for slag making, the alkalinity R is 3-6, and the slag time is more than or equal to 15 minutes.
  8. 8. The production method according to claim 5, wherein the billet continuous casting is performed by adopting billet continuous casting, the primary cooling water flow is 105-120m 3 /h, the secondary cooling specific water flow is 0.50-0.65l/kg, and the low-pulling-speed casting is performed by adopting the pulling speed of 1.9-2.3m/min.
  9. 9. The method according to claim 5, wherein the heating is controlled at 1170-1250 ℃ for a heating time of >120 minutes, wherein the soaking time is >30 minutes.
  10. 10. The method according to claim 5, wherein the bar is rolled at a start rolling temperature of 1130-1180 ℃ and a finish rolling temperature of 1020-1080 ℃, the controlled cooling is performed by passing water through the bar after rolling, and the bar is cooled to an upper cooling bed temperature of 550-650 ℃ and is cooled by cooling bed air.

Description

400 MPa-grade high-manganese high-ductility non-magnetic vibration-resistant steel bar and production method thereof Technical Field The invention belongs to the field of non-magnetic vibration-resistant steel bars, and particularly relates to a 400 MPa-grade high-manganese high-ductility non-magnetic vibration-resistant steel bar and a production method thereof. Background Under the strong magnetic field environment, ferromagnetic materials represented by iron can be subjected to the action of magnetic force, and the magnetism of the materials is enhanced after the materials are influenced by the magnetic field, so that the stress is continuously increased. The steel bars in the cast-in-situ reinforced concrete structure creep under the action of a strong magnetic field, and the creep continuously develops, so that the reinforced concrete protection layer concrete is finally cracked or even the whole member is destroyed, thereby influencing the use safety of the whole building. In order to realize normal use of the concrete structure in a strong magnetic environment, effective magnetization-free measures must be adopted for the construction of the steel bar engineering, the template engineering and the concrete engineering in the construction process. The demand of the non-magnetic steel bar is derived from the urgent demand of modern technology on the 'zero magnetic environment', and the necessity of the non-magnetic steel bar is reflected in the aspects of functional guarantee, safety promotion, compliance requirements and the like. With the further development of high-end manufacturing, medical health and national defense science and technology, nonmagnetic reinforcing steel bars become one of core materials in the special engineering field, and the building materials are promoted to be upgraded in the functionalized and customized directions. The non-magnetic steel bar has a relatively wide application prospect. In the fields of magnetic shielding, zero magnetic space, magnetic levitation railway track construction and the like, nonmagnetic steel bars are adopted to prevent the influence of magnetic fields. The development of the nonmagnetic steel bar with low cost, low magnetic conductivity and high performance has important significance for civil and national defense military construction in China. The patent with publication number CN 117802392A published in 4 months and 2 days of 2024 discloses a preparation method of a zero magnetic steel bar for a special nonmagnetic concrete structure, which comprises the following steps of S1 smelting, wherein raw materials are melted, chemical components are adjusted, S2 rolling, the shape and the size are changed through calendaring to prepare the steel bar, S3, the non-magnetic steel post-treatment, the surface magnetic substances are removed through physical pretreatment, chemical pretreatment and powder spraying, the zero magnetic steel bar for the special nonmagnetic concrete structure prepared through the steps ensures that the residual magnetism is less than or equal to 0.5nT (zero measuring distance is 2 cm), but the zero magnetic steel bar produced by the patent is produced through die casting, the yield is low, and the cost is high. And the finished steel bar product is required to be subjected to powder spraying treatment, so that the cost is high. Therefore, it is necessary to provide a non-magnetic vibration-resistant reinforcing steel bar which is low in cost and suitable for industrial production. Disclosure of Invention The invention aims to provide a 400 MPa-grade high-manganese high-ductility non-magnetic vibration-resistant steel bar and a production method thereof, which are used for obtaining the 400 MPa-grade ultra-high manganese steel non-magnetic vibration-resistant steel bar in a reinforced concrete structure in a strong magnetic field environment through component design and process production control, so that the normal use of the concrete structure in the strong magnetic field environment is realized without powder spraying treatment, and the steel bar does not creep. The specific technical scheme of the invention is as follows: A400 MPa-grade high-manganese high-ductility non-magnetic vibration-resistant steel bar comprises the following components in percentage by mass: C 0.25%-0.35%、Si 0.50%-0.70%、Mn 15.0%-24.0%、V 0.2%-0.4%、Nb 0.01%-0.03%、Als 0.01%-0.04%、N 0.20-0.60%、P≤0.015%、S≤0.005%, The balance of Fe and other unavoidable impurities. The components of the 400 MPa-grade high-manganese high-ductility non-magnetic vibration-resistant steel bar meet the conditions that A value=33×C% +0.1×Mn% +18×N% > 16 and B value=33×C% -Mn% -10. Each element symbol represents the content x 100, and the numerical value before the% is substituted into calculation. The microstructure of the 400 MPa-grade high-manganese high-ductility non-magnetic shock-resistant steel bar is austenite at normal temperature, and the area ratio of the austenite in a