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CN-119710455-B - Stress corrosion resistant high-strength steel for round-link chain for mine and preparation method thereof

CN119710455BCN 119710455 BCN119710455 BCN 119710455BCN-119710455-B

Abstract

The invention discloses stress corrosion resistant high-strength steel for a mining round-link chain and a preparation method thereof, belongs to the technical field of steel for round-link chains, and solves the problem that the strength, toughness and stress corrosion resistance of the steel for the round-link chain cannot be effectively improved simultaneously in the prior art. The high-strength mining round-link chain steel resistant to stress corrosion comprises the following components in percentage by mass, wherein the balance of ：C：0.22％～0.27％、Si：0.10％～0.17％、Mn：0.48％～0.62％、P：≤0.015％、S：≤0.005％,Cr：0.41％～0.66％、Ni：0.88％～1.23％、Mo：0.41％～0.58％、Cu：0.40％～0.60％、V：0.18％～0.36％、W：0.21％～0.45％, is Fe and unavoidable impurities. The high-strength steel for the mining round-link chain is high in strength, good in toughness and excellent in stress corrosion resistance.

Inventors

  • SUN XINJUN
  • LIANG XIAOKAI
  • WANG XIN
  • Tong shuai
  • JIA SHUJUN
  • ZHU XIUGUANG
  • Gao Yinguo

Assignees

  • 钢铁研究总院有限公司
  • 中煤张家口煤矿机械有限责任公司

Dates

Publication Date
20260508
Application Date
20241204

Claims (8)

  1. 1. The stress corrosion resistant high-strength steel for the mining round-link chain is characterized by comprising the following components in percentage by mass, the balance of ：C：0.22%～0.27%、Si：0.10%～0.17%、Mn：0.48%～0.62%、P：≤0.015%、S：≤0.005%,Cr：0.41%～0.53%、Ni：0.88%～1.23%、Mo：0.41%～0.58%、Cu：0.40%～0.60%、V：0.18%～0.36%、W：0.21%～0.45%, is Fe and unavoidable impurities; The microstructure of the high-strength mining round-link chain steel resistant to stress corrosion comprises lath martensite and a nano-grade precipitated phase, wherein the nano-grade precipitated phase mainly comprises (V, mo, W) C composite nano-grade precipitated phase, the mass percentage of the nano-grade precipitated phase is about 0.3% -1%, and the average lath spacing of the lath martensite is 120-200 nm; The yield strength of the high-strength mining round-link chain steel resistant to stress corrosion is more than or equal to 1170MPa, the tensile strength is more than or equal to 1210MPa, the area shrinkage is more than or equal to 60%, the elongation after fracture is more than or equal to 14%, the normal-temperature impact toughness A kv2 is more than or equal to 100J, and the stress intensity factor K ISCC resistant to stress corrosion cracking is more than or equal to 85 MPa m.
  2. 2. The stress corrosion resistant high strength steel for round-link chains for mines according to claim 1, wherein the components of the stress corrosion resistant high strength steel for round-link chains for mines comprise ：C：0.22%～0.26%、Si：0.10%～0.16%、Mn：0.48%～0.61%、P：≤0.015%、S：≤0.005%,Cr：0.41%～0.53%、Ni：0.88%～1.20%、Mo：0.41%～0.55%、Cu：0.41%～0.60%、V：0.18%～0.32%、W：0.21%～0.42%, balance Fe and unavoidable impurities in mass percent.
  3. 3. The stress corrosion resistant high strength steel for a round-link chain for mines according to claim 1, wherein the stress corrosion cracking resistant stress intensity factor K ISCC of the stress corrosion resistant high strength steel for a round-link chain for mines is 87 to 93 MPa v.
  4. 4. A method for preparing the stress corrosion resistant high-strength steel for a round-link chain for a mine, characterized in that the method is used for preparing the stress corrosion resistant high-strength steel for a round-link chain for a mine as set forth in any one of claims 1 to 3, and the method comprises the steps of: step 1, smelting and casting into a blank; step2, rolling the blank to obtain a bar stock; And step 3, annealing and straightening the bar stock, and performing heat treatment to obtain the stress corrosion resistant high-strength steel for the mining round-link chain, wherein the heat treatment comprises normalizing, quenching and tempering.
  5. 5. The preparation method according to claim 4, wherein in the step 3, the normalizing heat preservation temperature is 890-930 ℃.
  6. 6. The preparation method according to claim 4, wherein in the step 3, the whole quenching is performed by a heating furnace, the temperature is raised to 860-890 ℃ and the heat is preserved for 40-120 min.
  7. 7. The method according to claim 4, wherein in the step 3, the quenching is performed by electromagnetic induction heating, the bar stock is heated to 900-920 ℃, and the bar stock is cooled to room temperature after heat preservation for 3-10 seconds.
  8. 8. The method according to any one of claims 4 to 7, wherein in the step3, the tempering temperature is 610-640 ℃.

Description

Stress corrosion resistant high-strength steel for round-link chain for mine and preparation method thereof Technical Field The invention relates to the technical field of steel for round-link chains, in particular to stress corrosion resistant high-strength steel for mining round-link chains and a preparation method thereof. Background The mining round-link chain is a transmission chain on a coal mining scraper conveyor and a loader, is not only a key part of equipment, but also a vulnerable part, and once the equipment is broken and failed, the whole production line can be influenced, so that the coal mining efficiency of a fully-mechanized mining working face is seriously influenced. With the improvement and heavy development of the comprehensive performance of materials used by other components of the coal face at present, the limitation of the material performance of a round link chain limits the improvement of the production capacity of equipment, and is a prominent short plate for limiting the service life of the whole scraper conveyor. The mining round-link chain is mainly used in underground service, a large amount of corrosive mediums such as coal dust, rock dust, moist air, salt dissolved in water and the like exist underground, oxygen is enriched, and meanwhile, the mining round-link chain is surrounded by corrosive gas generated in the mining process, so that the environment is extremely complex and severe. Although the use of round-link chains places high demands on toughness, fatigue properties and wear resistance, the failure mode of round-link chains is largely not purely fatigue fracture and plastic deformation fracture, but rather is a sudden, corrosive brittle failure without deformation precursors at well below yield strength. Therefore, on the premise of ensuring the comprehensive mechanical properties, attention is particularly paid to the influence of the corrosion environment on the round-link chain. The stress distribution of the shoulder and the top of the chain ring is most concentrated, local stress concentration is extremely easy to cause stress corrosion cracking of high-strength steel in a corrosive environment, and once stress corrosion occurs, the cracks rapidly expand in a short time, so that the service life of the material can be greatly reduced. The surface of the round-link chain is damaged after a period of time under the influence of underground corrosive medium and abrasion, wherein (1) surface defects such as pitting and pit are generated, a closed battery is formed at the pit bottom, so that the local pH value is reduced, if the condition of cathodic hydrogen evolution reaction is reached, the generated hydrogen atoms are diffused into the metal at the tip of a crack, and (2) the fresh metal which is subjected to plastic deformation and is not protected by an oxide film is re-exposed to the corrosive environment, so that the metal is dissolved as an anode under the local electrochemical action, and the tip of the crack is continuously expanded. These tend to be the leading cause of stress corrosion cracking, which occurs in the case of round-link chains under the coupling of tensile loads and corrosive media. Therefore, the stress corrosion resistance of the mining round-link chain is improved, and the service life of the mining round-link chain in the pit can be effectively prolonged. However, the present invention patent of mining high-strength round-link chain has few researches on the stress corrosion cracking resistance of the round-link chain in terms of improving the corrosion resistance or the wear-resistant corrosion-resistant comprehensive performance of steel, so how to improve the stress corrosion resistance on the basis of ensuring the high strength and high toughness of the mining round-link chain is a problem to be solved. Disclosure of Invention In view of the above, the invention aims to provide the high-strength mining round-link chain steel with stress corrosion resistance and the preparation method thereof, which are used for solving the problem that the strength, toughness and stress corrosion resistance of the existing round-link chain steel cannot be effectively improved at the same time. The aim of the invention is mainly realized by the following technical scheme: The invention provides stress corrosion resistant high-strength steel for a mining round-link chain, which comprises the following components in percentage by mass of ：C：0.22％～0.27％、Si：0.10％～0.17％、Mn：0.48％～0.62％、P：≤0.015％、S：≤0.005％,Cr：0.41％～0.66％、Ni：0.88％～1.23％、Mo：0.41％～0.58％、Cu：0.40％～0.60％、V：0.18％～0.36％、W：0.21％～0.45％, and the balance of Fe and unavoidable impurities. Further, the high-strength mining round-link chain steel resistant to stress corrosion comprises the following components in percentage by mass, the balance of ：C：0.22％～0.26％、Si：0.10％～0.16％、Mn：0.48％～0.61％、P：≤0.015％、S：≤0.005％,Cr：0.41％～0.61％、Ni：0.88％～1.20％、Mo：0.41％～0.55％、Cu：0.41％～0.60％、V：0.18％～0.32％、W：0.21％～0.42％, bei