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CN-119710456-B - Ultrahigh-strength steel for round-link chain for mine and preparation method thereof

CN119710456BCN 119710456 BCN119710456 BCN 119710456BCN-119710456-B

Abstract

The invention discloses ultrahigh-strength steel for a round-link chain for a mine and a preparation method thereof, belongs to the technical field of steel for round-link chains, and solves the problem that the strength and toughness of the steel for the round-link chain in the prior art cannot be effectively improved at the same time. The steel for the ultra-high strength mining round-link chain 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：0.87％～1.13％、Cu：0％～0.60％、V：0.18％～0.36％、W：0.21％～0.45％, is Fe and unavoidable impurities. The ultra-high strength steel for the mining round-link chain has high strength and good plastic toughness.

Inventors

  • SUN XINJUN
  • LIANG XIAOKAI
  • WANG XIN
  • Tong shuai
  • ZHU XIUGUANG
  • JIA SHUJUN
  • LIU QINGYOU

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 steel for the ultra-high strength mining round-link chain is characterized by comprising the following components in percentage by mass, wherein the balance of ：C：0.22%～0.27%、Si：0.11%～0.17%、Mn：0.53%～0.62%、P：≤0.015%、S：≤0.005%,Cr：0.41%～0.66%、Ni：0.88%～1.08%、Mo：0.87%～1.13%、Cu：0.3%～0.60%、V：0.18%～0.24%、W：0.21%～0.45%, is Fe and unavoidable impurities; the microstructure of the ultra-high strength steel for the mining round-link chain comprises lath martensite and a nano precipitated phase, wherein the nano precipitated phase mainly comprises (V, mo, W) C composite nano precipitated phase, the mass percent of the nano precipitated phase is 0.3% -1.5%, and the average lath spacing of the lath martensite is 130-185 nm; The yield strength of the steel for the ultra-high strength mining round-link chain is more than or equal to 1310MPa, the tensile strength is more than or equal to 1350MPa, and the normal-temperature impact toughness A kv2 is more than or equal to 80J.
  2. 2. The ultra-high strength steel for a round-link chain for mines according to claim 1, wherein the components of the ultra-high strength steel for a round-link chain for mines comprise ：C：0.23%～0.27%、Si：0.11%～0.16%、Mn：0.53%～0.62%、P：≤0.015%、S：≤0.005%,Cr：0.42%～0.64%、Ni：0.90%～1.08%、Mo：0.89%～1.12%、Cu：0.30%～0.60%、V：0.18%～0.24%、W：0.21%～0.43%, the balance of Fe and unavoidable impurities in mass percent.
  3. 3. The ultra-high strength steel for a round-link chain for mines according to claim 1, wherein the yield strength of the ultra-high strength steel for a round-link chain for mines is 1311 to 1420mpa and the tensile strength is 1360 to 1480mpa.
  4. 4. A method for preparing the steel for the ultra-high strength mining round-link chain, which is characterized in that the method is used for preparing the steel for the ultra-high strength mining round-link chain according to any one of claims 1 to 3, and comprises the following steps: 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 steel for the ultra-high strength 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 885-927 ℃.
  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 895-925 ℃, and the bar stock is cooled to room temperature after heat preservation for 3-10 s.
  8. 8. The method according to any one of claims 4 to 7, wherein in the step 3, the tempering temperature is 560 to 620 ℃.

Description

Ultrahigh-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 steel for an ultrahigh-strength mining round-link chain and a preparation method thereof. Background The mining round-link chain is an important transmission part in the fully-mechanized mining equipment of the coal mine, has the advantages of high transmission efficiency, large bearing capacity and convenient disassembly and assembly, and can bear tensile, alternating and impact loads simultaneously in the underground service process. The chain structure often has the characteristic of dynamic range change in the operation process, and once fracture failure occurs, the comprehensive mining efficiency of equipment can be seriously affected, so that huge economic loss is caused. Therefore, the steel has extremely high requirements on the comprehensive mechanical properties of the steel for the round-link chain. Along with the development direction of large-scale, high-power and high-strength coal mining equipment, the limitations of the existing round-link chain materials have become prominent short plates for limiting the improvement of the production capacity of the equipment, and the specification and strength level of the round-link chain are urgently required to be improved. The mining high-strength round-link chain can be classified into B, C, D three grades according to the standard GB/T12718-91. At present, under the D-level high strength, the brittle fracture of the chain occurs, and although all indexes reach the national standard, the brittle fracture is difficult to popularize and apply in actual industrial production. Therefore, new mining round-link chain steels of higher grade and meeting the development requirements of the mining industry are required to have performance characteristics that are a combination of ultra-high strength and excellent ductile properties, however, currently few studies are related thereto. Disclosure of Invention In view of the above, the invention aims to provide the steel for the ultra-high strength mining round-link chain and the preparation method thereof, which are used for solving the problem that the strength and toughness of the existing steel for the round-link chain cannot be effectively improved at the same time. The aim of the invention is mainly realized by the following technical scheme: The invention provides ultra-high strength steel for a mining round-link chain, which 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：0.87％～1.13％、Cu：0％～0.60％、V：0.18％～0.36％、W：0.21％～0.45％, is Fe and unavoidable impurities. Further, the ultra-high strength steel for the mining round-link chain comprises the following components in percentage by mass, wherein the balance of ：C：0.23％～0.27％、Si：0.10％～0.16％、Mn：0.50％～0.62％、P：≤0.015％、S：≤0.005％,Cr：0.42％～0.64％、Ni：0.90％～1.20％、Mo：0.89％～1.12％、Cu：0.30％～0.60％、V：0.18％～0.35％、W：0.21％～0.43％, is Fe and unavoidable impurities. Further, the microstructure of the ultra-high strength steel for the round-link chain for the mine comprises lath martensite and nano precipitated phases. Further, in the microstructure of the ultra-high strength steel for the round-link chain for the mine, the nano-scale precipitated phase mainly comprises a (V, mo, W) C composite nano-scale precipitated phase. Further, the yield strength of the steel for the ultra-high strength mining round-link chain is more than or equal to 1310MPa, and the tensile strength is more than or equal to 1350MPa. The invention also provides a preparation method of the steel for the ultra-high strength mining round-link chain, which is used for preparing the steel for the ultra-high strength mining round-link chain and comprises the following 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 steel for the ultra-high strength mining round-link chain, wherein the heat treatment comprises normalizing, quenching and tempering. Further, in the step 3, the normalizing heat preservation temperature is 885-927 ℃. Further, in the step 3, the whole quenching is heated by a heating furnace, the temperature is raised to 860-890 ℃ and the heat preservation time is 40-120 min. In the step 3, the bar stock is heated to 895-925 ℃ by electromagnetic induction heating, and is cooled to room temperature after heat preservation for 3-10 seconds. Further, in the step 3, the tempering heat preservation temperature is 560-620 ℃. Compared with the prior art, the invention can at least realize one of the following beneficial effects: According to the steel for the ultra-high-strength mining round-link chain, the content of C, si, ni, mn, cr, mo