Search

CN-121428425-B - Low-temperature corrosion-resistant steel plate for 355 MPa-level frozen soil highway and preparation method thereof

CN121428425BCN 121428425 BCN121428425 BCN 121428425BCN-121428425-B

Abstract

The invention relates to the technical field of low-temperature corrosion-resistant steel, in particular to a 355 MPa-grade low-temperature corrosion-resistant steel plate for a frozen soil highway and a preparation method thereof, wherein the low-temperature corrosion-resistant steel plate comprises ：C：0.03～0.14%,Si：0.2～0.6%,Mn：0.8～1.5%,P：≤0.015％,S：≤0.006%,Ni：0.01～0.30%,Cr：0.01～0.30%,Cu：0.02～0.30%,Ce+La：0.001～0.020%,Nb：0.001～0.080%,Al：0.001～0.015%,Ti：0.001～0.050%, weight percent of Fe and unavoidable trace inclusions as the balance. The scheme can ensure that the steel has good impact toughness (KV 2 is more than or equal to 120J) at the temperature of-45 ℃, solves the problem that the corrosion resistance of the existing steel is poor in the plateau frozen soil environment, and ensures that the relative corrosion rate is lower than 50% of that of the common Q355 steel.

Inventors

  • FENG GUANGHONG
  • ZHANG HONGLIANG
  • HU YANBIN
  • WANG WEIWEI
  • ZHAO FEIYU
  • XIAO JINFU
  • ZHAO YIGUANG

Assignees

  • 钢铁研究总院有限公司

Dates

Publication Date
20260508
Application Date
20251231

Claims (7)

  1. 1. A355 MPa grade frozen soil highway low temperature corrosion resistant steel plate is characterized in that ：C：0.03～0.14%,Si：0.2～0.6%,Mn：0.8～1.5%,P：≤0.015％,S：≤0.006%,Ni：0.01～0.30%,Cr：0.01～0.30%,Cu：0.02～0.30%,Ce+La：0.001～0.015%,Nb：0.001～0.080%,Al：0.001～0.015%,Ti：0.001～0.050%, weight percent of chemical components are Fe and unavoidable trace inclusions, and the total mass fraction of Ni, cr and Cu is more than or equal to 0.5%; The hot-rolled structure is a fine-grained ferrite and pearlite structure, wherein the content of the fine-grained ferrite is more than 80%; The preparation method of the 355 MPa-grade low-temperature corrosion-resistant steel plate for the frozen soil highway comprises the following steps: S1, smelting, namely smelting raw materials by adopting a converter or an electric furnace to obtain molten steel; S2, refining, namely refining molten steel through an LF furnace, and adding rare earth elements into the molten steel after refining; S3, continuous casting, namely continuously casting the refined molten steel to form a steel billet; s4, heating, namely heating the steel billet obtained by continuous casting to 1200-1250 ℃; S5, controlling rolling, namely performing rough rolling and finish rolling on the heated billet, and performing low-temperature rolling on the finish rolling in a non-recrystallization region, wherein the initial rolling temperature of the finish rolling is 800-850 ℃; s6, carrying out low-temperature crimping, namely controlling and cooling the rolled steel billet to carry out low-temperature crimping in ferrite and pearlite areas, wherein the coiling temperature is 600-650 ℃.
  2. 2. The 355 MPa-grade frozen earth highway low-temperature corrosion-resistant steel plate according to claim 1, wherein the carbon element content in the 355 MPa-grade frozen earth highway low-temperature corrosion-resistant steel plate is controlled to be 0.03% -0.08%.
  3. 3. The 355 MPa-grade frozen soil highway low-temperature corrosion-resistant steel plate according to claim 1, wherein the total mass fraction of Al, nb and Ti is more than or equal to 0.03%.
  4. 4. The 355 MPa-grade frozen earth highway low-temperature corrosion-resistant steel plate according to claim 1, wherein the 355 MPa-grade frozen earth highway low-temperature corrosion-resistant steel plate has a grain size of 10-12 grades.
  5. 5. The low-temperature corrosion-resistant steel sheet for 355 MPa-grade frozen earth road according to claim 1, wherein the corrosion rate of the low-temperature corrosion-resistant steel sheet for 355 MPa-grade frozen earth road with respect to the corrosion-resistant steel sheet Q355B is <50%.
  6. 6. The low-temperature corrosion-resistant steel sheet for 355 MPa-grade frozen earth road according to any one of claims 1 to 5, characterized in that the impact power average value of the low-temperature corrosion-resistant steel sheet for 355 MPa-grade frozen earth road at-45 ℃ is between 125J and 160J.
  7. 7. A method for preparing a 355 MPa-grade low-temperature corrosion-resistant steel sheet for a frozen soil highway, characterized by comprising: s1, smelting: smelting raw materials by adopting a converter or an electric furnace to obtain molten steel; s2, refining: refining molten steel by an LF furnace, and adding rare earth elements into the molten steel after refining; s3, continuous casting: Continuously casting the refined molten steel to form a steel billet; s4, heating: heating a billet obtained by continuous casting to 1200-1250 ℃; s5, controlling rolling: Carrying out rough rolling and finish rolling on the heated billet, and carrying out low-temperature rolling on the finish rolling in a non-recrystallization zone, wherein the initial rolling temperature of the finish rolling is 800-850 ℃; S6, low-temperature crimping: and (3) performing controlled cooling on the rolled steel billet until the steel billet is curled at a low temperature in ferrite and pearlite areas, wherein the coiling temperature is 600-650 ℃.

Description

Low-temperature corrosion-resistant steel plate for 355 MPa-level frozen soil highway and preparation method thereof Technical Field The invention relates to the technical field of low-temperature corrosion-resistant steel, in particular to a 355 MPa-grade low-temperature corrosion-resistant steel plate for a frozen soil highway and a preparation method thereof. Background Engineering construction of frozen soil areas has faced a number of technical difficulties. These areas often have extreme environmental characteristics of high cold, high radiation, and frequent freeze-thaw cycles. Degradation of permafrost results in uneven settlement of foundations for road and bridge construction, severely affecting the service life of roads and bridges. The existing steel has the defects in low-temperature performance and corrosion resistance. For example, ordinary steels are prone to brittle fracture in low temperature environments, and cannot meet the use requirements of extremely low temperatures (e.g., -20 ℃ or-45 ℃) in permafrost regions. In addition, the soil in the frozen soil area is rich in chloride ions and sulfate ions, and the corrosion rate of the steel can be accelerated by the components, so that the service life of the steel is shortened. The existing low-temperature steel and corrosion-resistant steel cannot simultaneously meet the comprehensive requirements of road and bridge construction in permafrost regions on low-temperature toughness, corrosion resistance and mechanical properties. Disclosure of Invention In view of the analysis, the invention aims to provide a 355 MPa-grade frozen soil highway low-temperature corrosion-resistant steel plate and a preparation method thereof, which are used for solving at least one of the problems of high low-temperature brittleness, insufficient low-temperature corrosion resistance, difficulty in considering low-temperature toughness, poor freeze-thawing resistance and large deformation capacity and the like in the prior art. The aim of the invention is mainly realized by the following technical scheme: A355 MPa grade frozen soil highway low temperature corrosion resistant steel plate comprises the chemical components of ：C：0.03～0.14%,Si：0.2～0.6%,Mn：0.8～1.5%,P：≤0.015％,S：≤0.006%,Ni：0.01～0.30%,Cr：0.01～0.30%,Cu：0.02～0.30%,Ce+La：0.001～0.020%,Nb：0.001～0.080%,Al：0.001～0.015%,Ti：0.001～0.050%, percent by weight and the balance of Fe and unavoidable trace inclusions. Preferably, the hot rolled structure of the 355MPa grade frozen earth highway low temperature corrosion resistant steel plate is a fine grain ferrite and pearlite structure, wherein the content of fine grain ferrite is >80%. Preferably, the carbon content of the 355 MPa-grade low-temperature corrosion-resistant steel plate for the frozen soil highway is controlled to be 0.03% -0.08%. Preferably, the total mass fraction of Ni, cr and Cu is more than or equal to 0.5%. Preferably, the total mass fraction of Ce and La is more than or equal to 0.001%. Preferably, the total mass fraction of Al, nb and Ti is more than or equal to 0.03%. Preferably, the grain size of the 355MPa grade frozen soil highway low temperature corrosion resistant steel plate is 10-12 grade. Preferably, the relative corrosion rate of the 355MPa grade frozen soil highway low temperature corrosion resistant steel plate is less than 50 percent. Preferably, the impact energy average value of the 355MPa grade frozen soil highway low temperature corrosion resistant steel plate at the temperature of-45 ℃ is between 125J and 160J. A method for preparing a 355 MPa-grade low-temperature corrosion-resistant steel plate for a frozen soil highway, which is used for preparing the 355 MPa-grade low-temperature corrosion-resistant steel plate for the frozen soil highway, and comprises the following steps: s1, smelting: smelting raw materials by adopting a converter or an electric furnace to obtain molten steel; s2, refining: refining molten steel by an LF furnace, and adding rare earth elements into the molten steel after refining; s3, continuous casting: Continuously casting the refined molten steel to form a steel billet; s4, heating: heating a billet obtained by continuous casting to 1200-1250 ℃; s5, controlling rolling: carrying out rough rolling and finish rolling on the heated billet, and carrying out low-temperature rolling on the finish rolling in a non-recrystallization zone; S6, low-temperature crimping: and (3) performing controlled cooling on the rolled billet until the billet is curled at a low temperature in a ferrite region and a pearlite region. Compared with the prior art, the invention has at least one of the following beneficial effects: (1) According to the invention, by adding nickel (Ni), chromium (Cr), copper (Cu) and other elements, the brittle transition temperature of the steel plate is obviously reduced, the low-temperature toughness is improved, the corrosion resistance of the steel is improved, particularly, the corrosion resis