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CN-120082811-B - 400 MPa-grade seawater corrosion-resistant high-manganese non-magnetic steel bar steel and production method thereof

CN120082811BCN 120082811 BCN120082811 BCN 120082811BCN-120082811-B

Abstract

The invention provides 400 MPa-grade seawater corrosion-resistant high-manganese non-magnetic steel bar steel and a production method thereof, wherein the components are as follows: 0.20-0.35% of C, 0.25-0.40% of Si, 15-25% of Mn, 3-5% of Cr, less than or equal to 0.025% of P, less than or equal to 0.020% of S, 0.05-0.10% of V, 2.0-3.5% of Al, 0.015-0.020% of N, 4.2-or equal to L=1.5× [ C ] +0.20× [ Mn ] +0.20× [ Cr ] +10.0× [ N ]. Ltoreq.5.8, and the balance of Fe and unavoidable impurity elements. Compared with the prior art, the invention adopts high Mn and is matched with C, N, al to ensure the low permeability of the steel bar; cr and V are added to ensure the mechanical property and corrosion resistance of the product by matching with the production method.

Inventors

  • YU LIANGQI
  • YUAN YUE
  • WANG KAIZHONG
  • WANG MIN
  • CHEN PENGFEI
  • YANG YINGDONG
  • GUO ZHAN
  • YIN DEFU
  • ZHANG XIAORUI
  • JIANG TING

Assignees

  • 马鞍山钢铁有限公司

Dates

Publication Date
20260508
Application Date
20250331

Claims (8)

  1. 1. The 400 MPa-level seawater corrosion-resistant steel for the high-manganese non-magnetic steel bar is characterized by comprising the following components in percentage by mass: C 0.20-0.35%,Si 0.25-0.40%,Mn 15-25%,Cr 3-5%,P≤0.025%、S≤0.020%,V 0.05-0.10%,Al 2.0-3.5%,N 0.015-0.020%, The balance of Fe and unavoidable impurity elements; the chemical components of the 400 MPa-grade seawater corrosion resistant high-manganese non-magnetic steel bar are satisfied that L=1.5 xC+0.20 xMn+0.20 xCr+10.0 xN is not more than 4.2 and not more than 5.8; The R eL ≥400MPa、R m of the 400 MPa-grade seawater corrosion-resistant high-manganese non-magnetic steel bar steel is more than or equal to 600MPa, A is more than or equal to 30%, and the average corrosion rate of the corrosion-resistant steel bar is 2.20-2.62 g/(m 2 .h).
  2. 2. The 400 MPa-grade seawater corrosion-resistant high-manganese nonmagnetic steel bar steel according to claim 1, wherein the structure of the 400 MPa-grade seawater corrosion-resistant high-manganese nonmagnetic steel bar steel is austenite.
  3. 3. A method for producing the 400 MPa-grade seawater corrosion-resistant high-manganese nonmagnetic steel for steel bar according to claim 1 or 2, characterized in that the production method comprises the following process flows: smelting, LF refining, RH vacuum treatment, continuous casting and rolling.
  4. 4. The method according to claim 3, wherein the smelting comprises adding scrap steel and ferromanganese alloy, and adding molten iron, wherein the molten iron accounts for 30-50%, the scrap steel and ferromanganese alloy accounts for 70-50% of the end point, P is less than or equal to 0.010%, S is less than or equal to 0.010%, and the temperature is 1560-1610 ℃.
  5. 5. The production method according to claim 3, wherein the LF furnace refining is performed at a temperature of 1565-1585 ℃.
  6. 6. The production method according to claim 3, wherein the RH vacuum degassing is performed at a molten steel temperature of 1525-1545 ℃ when the ladle is fed into the RH vacuum furnace, a vacuum holding time is more than or equal to 12 minutes in the early stage of vacuum, a vacuum holding time of more than or equal to 8 minutes is ensured after component adjustment in the vacuum stage, and a tapping RH vacuum furnace temperature of 1485-1505 ℃.
  7. 7. A production method according to claim 3, characterized in that the continuous casting, casting temperature 1445-1470 ℃, mold cooling water flow 3000 liter/min, secondary cooling specific water quantity 0.8-1.2 liter/kg.
  8. 8. A production method according to claim 3, wherein the rolling is performed by a continuous bar mill, the heating temperature is controlled to 1150-1250 ℃, the tapping temperature is controlled to 980-1080 ℃, three sections of water cooling are adopted after finish rolling, the temperature is reduced by 150-250 ℃, and the upper cooling bed temperature is controlled to 800-900 ℃.

Description

400 MPa-grade seawater corrosion-resistant high-manganese non-magnetic steel bar steel and production method thereof Technical Field The invention belongs to the technical field of hot rolled steel bars for reinforced concrete and production processes thereof, and particularly relates to 400 MPa-level seawater corrosion-resistant high-manganese non-magnetic steel bar steel and a production method thereof. Background The non-magnetic steel is used as a steel functional material, the room temperature structure of the non-magnetic steel is required to be stable austenite, the austenite with a face-centered cubic structure is paramagnetic, the relative magnetic permeability mu value is slightly more than 1, and the magnetization effect in a magnetic field is close to the phenomenon of non-magnetism, so the non-magnetic steel is visually called as the non-magnetic steel. The magnetism-avoiding shelter in the building industry can be protected from a magnetic field by adopting non-magnetic steel, and the safety of a building structure is protected. The patent with publication number CN 115478219A, published on 12/16 of 2022 discloses a low-magnetic deformed steel for construction and a preparation method thereof, wherein the rest of the components ：C 0.08-0.60％;Si0.10-1.00％;Mn 15.00-28.00％;Al0.02-4.50％;P≤0.045％;S≤0.045％;Nb0.01-0.30％;Ti 0.01-0.20％;V 0.01-0.20％, are iron and unavoidable impurities, and the production method comprises the steps of smelting molten steel, continuous casting or die casting, homogenizing a billet heating furnace, continuous rolling, water cooling, acid washing, high-pressure water cleaning, hot water treatment and antirust agent treatment to obtain a low-magnetic deformed steel product. However, the yield strength Rp 0.2 is more than or equal to 335MPa, the mechanical property of the product produced by the prior art can not meet the requirement of 400MPa, and in order to ensure low magnetic property, the working procedures of acid washing, rust inhibitor treatment and the like are additionally added, so that the production cost is greatly increased. Therefore, it is necessary to provide a product with simple process and better mechanical properties. Disclosure of Invention The invention aims to provide 400 MPa-grade seawater corrosion-resistant high-manganese non-magnetic steel for reinforcing steel bars and a production method thereof, wherein Mn, cr and Al are added, and a steel making and rolling process is combined, so that an austenite structure is formed at room temperature, the requirement that the magnetic permeability is less than or equal to 1.05 is met, and V is added, the precipitation strengthening effect is utilized, so that the mechanical properties of the steel bars are improved, and R eL≥400MPa、Rm is more than or equal to 600MPa, and A is more than or equal to 30%. And the corrosion resistance is evaluated by adopting a pericycle corrosion test, is 2 times or more than that of a common HRB400E steel bar, and can meet the technical requirements of key engineering in coastal areas on the mechanical properties of non-magnetic steel bars. Moreover, the production process of the invention is not complex, and is suitable for large-scale industrial production and popularization and application. The specific technical scheme of the invention is as follows: The 400 MPa-grade seawater corrosion-resistant high-manganese non-magnetic steel for the steel bar comprises the following components in percentage by mass: C 0.20-0.35％,Si 0.25-0.40％,Mn 15-25％,Cr 3-5％,P≤0.025％、S≤0.020％,V 0.05-0.10％,Al 2.0-3.5％,N 0.015-0.020％, The balance of Fe and unavoidable impurity elements. The chemical composition of the 400 MPa-grade seawater corrosion-resistant high-manganese non-magnetic steel bar is 4.2-L=1.5-C+0.20-Mn+0.20-Cr+10.0-N-5.8. To obtain high strength and nonmagnetic properties. In the formula, each symbol represents the content of the corresponding chemical component by 100%. The structure of the 400 MPa-grade seawater corrosion-resistant high-manganese non-magnetic steel bar steel is austenite. The R eL≥400MPa、Rm of the 400 MPa-grade seawater corrosion-resistant high-manganese non-magnetic steel bar steel is more than or equal to 600MPa, and A is more than or equal to 30%. The corrosion-resistant steel bar has good seawater corrosion resistance, the average corrosion rate of the corrosion-resistant steel bar is 2.20-2.62 g/(m 2 & h), and the corrosion resistance is evaluated by adopting a dip corrosion test and is 2 times or more than that of the common HRB400E steel bar. Preferably, R eL≥430MPa、Rm is more than or equal to 630MPa, and A is more than or equal to 45%. The invention provides a production method of 400 MPa-grade seawater corrosion-resistant high-manganese non-magnetic steel for steel bars, which comprises the following process flows: smelting, LF refining, RH vacuum treatment, continuous casting and rolling. The smelting adopts an electric furnace or a converter for smelti