Search

CN-120006163-B - 500 MPa-grade low-temperature-resistant seawater-corrosion-resistant high-manganese non-magnetic steel bar steel and production method thereof

CN120006163BCN 120006163 BCN120006163 BCN 120006163BCN-120006163-B

Abstract

The invention provides 500MPa grade low temperature resistant seawater corrosion resistant high manganese non-magnetic steel bar steel and a production method thereof, wherein C is 0.30-0.50%, si is 0.25-0.45%, mn is 16-26%, P is less than or equal to 0.025%, S is less than or equal to 0.020%, V is 0.10-0.20%, nb is 0.01-0.02%, cr is 3.0-5.0%, al is 2.0-3.5%, N is 0.010-0.030%, L=1.5× [ C ] +0.20× [ Mn ] +0.20× [ Cr ] +10.0× [ N ]. Ltoreq.6.5, and the balance is Fe and unavoidable impurity elements. Compared with the prior art, the product produced by the invention has excellent mechanical properties at normal temperature, excellent mechanical properties at 165 ℃ in a low-temperature environment, relative magnetic permeability less than or equal to 1.05 and corrosion resistance which is 2 times or more than that of common HRB500E steel bars.

Inventors

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

Assignees

  • 马鞍山钢铁有限公司

Dates

Publication Date
20260512
Application Date
20250331

Claims (8)

  1. 1. The 500 MPa-level low-temperature-resistant seawater-corrosion-resistant high-manganese non-magnetic steel bar steel is characterized by comprising the following components in percentage by mass: C 0.30-0.50%,Si 0.25-0.45%,Mn 16-26%,P≤0.025%、S≤0.020%,V 0.10-0.20%,Nb 0.01-0.02%,Cr 3.0-5.0%,Al 2.0-3.5%,N 0.010-0.030%, The balance of Fe and unavoidable impurity elements; The 500MPa grade low temperature resistant seawater corrosion resistant high manganese non-magnetic steel bar steel also satisfies that L=1.5 xC+0.20 xMn+0.20 xCr+10.0 xN is not more than 4.6 and not more than 6.5; The 500 MPa-grade low-temperature-resistant seawater-corrosion-resistant high-manganese non-magnetic steel bar steel has magnetic conductivity not more than 1.05, R eL ≥500MPa、R m not less than 630MPa and A not less than 30%, an unopened sample R eL ≥575MPa、A gt not less than 3% in a low-temperature environment of-165 ℃, a notch sample A gt not less than 1%, a notch sensitivity index NSR not less than 1.00 and an average corrosion rate of 2.31-2.75 g/(m 2 .h).
  2. 2. The 500 MPa-level low-temperature-resistant seawater-resistant high-manganese non-magnetic steel bar steel according to claim 1, wherein the room-temperature structure of the 500 MPa-level low-temperature-resistant seawater-resistant high-manganese non-magnetic steel bar steel is austenite.
  3. 3. A production method of the 500 MPa-level low-temperature-resistant seawater-corrosion-resistant high-manganese nonmagnetic steel for steel bar according to claim 1 or 2, characterized by comprising the following process flows: Smelting, LF furnace refining, RH vacuum treatment, continuous casting and continuous bar rolling.
  4. 4. The production 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%, and the end point requirement is P, S-0.010% and the temperature is 1550-1600 ℃.
  5. 5. The production method according to claim 3, wherein the LF furnace refining is carried out by adding premelted refining slag 0.83-1.65kg/t, lime 6.67-8.33kg/t, TFe+MnO in slag less than or equal to 1.0%, and the temperature of the LF furnace is 1535-1555 ℃.
  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 an RH vacuum furnace temperature of 1455-1475 ℃.
  7. 7. A method according to claim 3, wherein the continuous casting is carried out at a casting temperature of 1420-1440 ℃, a crystallizer cooling water flow rate of 3000 liters/min, and a secondary cooling specific water flow rate of 0.8-1.2 liters/kg.
  8. 8. A production method according to claim 3, wherein the rolling is performed at 1150-1250 ℃, tapping temperature is 980-1080 ℃, three-stage water cooling is adopted after finish rolling, temperature is reduced by 150-250 ℃, and cooling bed temperature is 800-900 ℃.

Description

500 MPa-grade low-temperature-resistant seawater-corrosion-resistant high-manganese non-magnetic steel bar steel and production method thereof Technical Field The invention belongs to the technical field of non-magnetic steel bars, and particularly relates to 500 MPa-level steel for a low-temperature-resistant seawater corrosion-resistant high-manganese non-magnetic steel bar and a production method thereof. Background The nonmagnetic structural steel mainly adopts Fe-Mn nonmagnetic steel, and mainly utilizes higher Mn and C contents to obtain an austenitic structure at room temperature, so that the magnetic permeability of the steel material is kept at a lower level, and the nonmagnetic structural steel has the advantage of low manufacturing cost, but has the advantage of more severe use environment, is extremely easy to rust in the use process, and can improve the magnetic permeability by hundreds of times, thereby influencing the realization of the low magnetic function of the building engineering. There is no report on how to improve the corrosion resistance of non-magnetic steel. The patent with publication number CN 117512308A published in 2 month 6 of 2024 discloses a non-magnetic steel bar and a preparation method thereof, wherein the non-magnetic steel bar comprises the following chemical components of C, si, mn, P, S, cr, V, O, N and Fe, wherein the content of C is 0.55-0.65%, the content of Si is 0.45-0.55%, the content of Mn is 18.0-18.5%, the content of P is less than or equal to 0.010%, the content of S is less than or equal to 0.010%, the content of Cr is 3.0-3.5%, the content of V is 1.70-1.73%, the content of O is 0-0.0010%, and the content of N is 0.0140-0.0150% by mass. The content of C, V added in the prior art is too high, so that the reinforcing steel bars are easy to be brittle and hard, and the low-temperature performance is influenced. Moreover, there is no disclosure of how to improve corrosion resistance. Disclosure of Invention The invention aims to provide 500 MPa-level low-temperature-resistant seawater-corrosion-resistant high-manganese non-magnetic steel bar steel and a production method thereof, wherein a steel structure is formed at room temperature by adding Mn, al, cr, N and combining a steelmaking and steel rolling process, the requirement of magnetic permeability less than or equal to 1.05 is met, nb and V are added, the mechanical property of the steel bar is improved by utilizing precipitation strengthening effect, the normal-temperature performance reaches R eL≥500MPa、Rm more than or equal to 630MPa and A more than or equal to 30 percent, good low-temperature resistance performance is achieved, a notch-free sample R eL≥575MPa、Agt more than or equal to 3 percent, a notch sample A gt more than or equal to 1 percent, a notch sensitivity index NSR more than or equal to 1.00 (NSR=R m of the notch sample/R eL of the non-notch sample), the combination of Cr and N elements greatly improves the anti-pitting and intergranular corrosion performance, and the corrosion resistance performance is evaluated by adopting a peri-immersion corrosion test, and the corrosion resistance performance is more than 2 times of that of a common HRB500E steel bar, and the technical requirement of key engineering on the mechanical property of the non-magnetic steel bar in severe cold areas in winter can be met. The invention has the advantages of uncomplicated production process and suitability for large-scale industrial production, popularization and application. The invention provides 500 MPa-grade low-temperature-resistant seawater-corrosion-resistant high-manganese non-magnetic steel for steel bars, which comprises the following components in percentage by mass: C 0.30-0.50％,Si 0.25-0.45％,Mn 16-26％,P≤0.025％、S≤0.020％,V0.10-0.20％,Nb 0.01-0.02％,Cr 3.0-5.0％,Al 2.0-3.5％,N 0.010-0.030％, The balance of Fe and unavoidable impurity elements. The 500MPa grade low temperature resistant seawater corrosion resistant high manganese non-magnetic steel bar steel also satisfies that L=1.5 xC+0.20 xMn+0.20 xCr+10.0 xN is not more than 4.6 and not more than 6.5. To obtain high strength and non-magnetic properties. In the formula, each symbol represents the content of the corresponding chemical component by 100%. The room temperature structure of the 500 MPa-level low-temperature-resistant seawater-corrosion-resistant high-manganese non-magnetic steel bar steel is austenite. The magnetic conductivity of the 500 MPa-grade low-temperature-resistant seawater-corrosion-resistant high-manganese non-magnetic steel bar steel is less than or equal to 1.05; The 500 MPa-grade low-temperature-resistant seawater-corrosion-resistant high-manganese non-magnetic steel bar steel has R eL≥500MPa、Rm of more than or equal to 630MPa and A of more than or equal to 30 percent, an unnotched test sample R eL≥575MPa、Agt of more than or equal to 3 percent, a notched test sample A gt of more than or equal to 1 percent and a notch sensitivi