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CN-121976135-A - High-strength high-toughness steel plate for energy equipment and preparation method thereof

CN121976135ACN 121976135 ACN121976135 ACN 121976135ACN-121976135-A

Abstract

A steel plate for high-strength and high-toughness energy equipment and a preparation method thereof belong to the technical field of metallurgy. According to the invention, through the ingredient design combining the multi-element alloying and the micro-alloying, the cooperative regulation and control of the bundling and cooling control and the tempering heat treatment process, the effective control of the steel plate structure is realized, and the steel plate for high-strength high-toughness energy equipment with the thickness of 30 mm-50 mm, the yield strength of more than or equal to 1000MPa, the tensile strength of more than or equal to 1400MPa, the impact absorption power KV2 of more than or equal to 55J at-40 ℃ and the elongation after break of more than or equal to 13% is successfully prepared. The invention realizes the industrialized stable preparation of the steel plate for the ultra-high-strength energy equipment, and simultaneously combines good welding performance and manufacturing adaptability, and the steel plate provided by the invention can be used for thinning design of bearing members on the premise of ensuring structural safety and service reliability, thereby realizing the light weight of the energy equipment structure.

Inventors

  • WU ZHIQIANG
  • XIAO QIULI
  • XU GUILI
  • XIAO DAHENG
  • ZHU LIN
  • PENG YANG
  • QIAN YAJUN
  • DENG BIAO

Assignees

  • 湖南科技大学
  • 湖南钢铁集团技术研究院有限公司
  • 衡阳华菱钢管有限公司

Dates

Publication Date
20260505
Application Date
20260209

Claims (10)

  1. 1. A steel plate for high-strength and high-toughness energy equipment is characterized in that the steel plate comprises the following chemical components in percentage by weight ：C 0.15%~0.19%,Si 0.10%~0.30%,Mn 1.00%~1.20%,Al 0.02%~0.08%,Cr 0.20%~0.31%,Ni 0.60%~1.25%,Mo 0.20%~0.30%,Cu 0.05%~0.20%,V 0.02%~0.08%,Nb 0.019%~0.025%,Ti 0.0048%~0.0052%,B 0.0005%~0.0015%,P≤0.020%,S≤0.010%,, fe and unavoidable impurities, wherein the carbon equivalent CEQ of the steel plate for the energy equipment is less than or equal to 0.60%, and the welding crack sensitivity index Pcm is less than or equal to 0.35%.
  2. 2. The steel plate for high-strength and high-toughness energy equipment according to claim 1, wherein the thickness of the steel plate is 30-50 mm, the yield strength is not less than 1000MPa, the tensile strength is not less than 1400MPa, the impact absorption power KV2 is not less than 55J at-40 ℃, and the elongation after break is not less than 13%.
  3. 3. A method for producing the steel sheet for high-strength and high-toughness energy equipment according to claim 1 or 2, comprising the steps of: s1, smelting and continuous casting, namely, after the steel plate is proportioned according to the components, sequentially carrying out converter smelting, external refining and RH vacuum treatment, and then continuously casting into a steel billet; s2, rolling and cooling control, namely heating a continuous casting blank in a soaking pit, sequentially performing rough rolling and finish rolling, and cooling to room temperature according to a set speed, wherein rough rolling is performed by adopting a rolling mode with large rolling reduction, the rolling reduction of the previous 3 passes is not less than 25%, and the cumulative compression ratio of the rough rolling is not less than 3.2; s3, heat treatment, namely quenching and low-temperature tempering the cooled steel plate respectively to obtain the steel plate for the high-strength high-toughness energy equipment.
  4. 4. The method for preparing the steel plate for the high-strength and high-toughness energy equipment according to claim 3, wherein in S1, dephosphorization and desulfurization treatment are carried out in the converter smelting process, and the content of P at the end point is controlled to be less than or equal to 0.02 percent and the content of S is controlled to be less than or equal to 0.01 percent; The external refining adopts white slag operation; RH vacuum treatment time is more than or equal to 25min; when continuously casting into billets, the billets are obtained through whole-process protection casting, and the thickness range of the continuous casting billets is 150 mm-250 mm.
  5. 5. The method for preparing the steel plate for the high-strength and high-toughness energy equipment, according to claim 3, wherein in S2, a continuous casting blank is heated to 1100-1200 ℃ in a soaking pit, and is discharged after heat preservation for 1.5-2 hours, and the discharging temperature is 1100-1200 ℃; And the furnace time of the continuous casting billet is 180-240 min.
  6. 6. The method for manufacturing a steel plate for high-strength and high-toughness energy equipment according to claim 3, wherein in S2, the initial rolling temperature of rough rolling is 1040-1060 ℃, and the rolling pass is 4; And after rough rolling, the thickness of the blank is 46-75 mm.
  7. 7. The method for producing a steel sheet for high-strength and high-heat energy equipment according to claim 3, wherein in S2, the finish rolling start temperature is 880 ℃ to 920 ℃ and the finish rolling temperature is 800 ℃ to 860 ℃; 3-pass rolling is adopted, the rolling rate of each pass is 9% -20%, and the accumulated rolling rate is not more than 40%; and the thickness of the plate after finish rolling is 30-50 mm.
  8. 8. The method for producing a steel sheet for high-strength and high-heat energy equipment according to claim 3, wherein in S2, after the finish rolling, the steel sheet is cooled to 750 ℃ to 800 ℃ by air cooling, and then cooled to room temperature at a speed of 10 ℃ to 15 ℃ by using a laminar water cooling method.
  9. 9. The method for preparing the steel plate for the high-strength and high-heat energy equipment according to claim 3, wherein in the step S3, the steel plate is heated to 800-860 ℃ along with a furnace, kept for 10-30 min and then cooled to room temperature by water, and the quenching time is 15-30 min.
  10. 10. The method for manufacturing a steel plate for high-strength and high-heat energy equipment according to claim 3, wherein in the step S3, during low-temperature tempering, the quenched steel plate is placed in a furnace at 200-250 ℃ for 30-60 min, and then air-cooled to room temperature.

Description

High-strength high-toughness steel plate for energy equipment and preparation method thereof Technical Field The invention belongs to the technical field of metallurgy, and particularly relates to a steel plate for high-strength and high-toughness energy equipment and a preparation method thereof. Background With the rapid development of hydropower, wind power and other large-scale energy equipment, the related bearing and bearing structures are evolving in the forward high-parametrization, large-scale and light-weight directions. As a key structural material, the steel plate for energy equipment is required to have a higher strength level to meet the requirements of component thinning and bearing capacity improvement, and also to maintain good low-temperature toughness and manufacturing adaptability under medium and thick specification conditions so as to ensure safe and long-term reliable operation of the equipment in complex service environments and large-scale engineering applications. The steel for energy equipment widely applied in the current engineering mainly comprises low-alloy high-strength structural steel, and the strength grade is usually concentrated in the range of 600-900 MPa. Along with the continuous improvement of the design stress level, the existing low-alloy high-strength steel often depends on the improvement of the carbon content or the increase of the alloy element dosage to obtain strength reserve in the process of developing to higher strength grade, which not only narrows a tissue regulation window, but also is more prone to cause the problems of plasticity, low-temperature toughness reduction and the like under the condition of thick specification, thereby limiting the further application of the steel in high-bearing and large-thickness energy equipment structures. Under the background, a great deal of researches have been carried out in China and a series of patent technical schemes are formed around the component design and preparation process of medium-thick and thick high-strength steel plates for energy equipment. For example, patent CN114293110a proposes a thick 800 MPa-level hydroelectric steel plate, and by designing low-carbon components and matching with quenching-tempering technology, strength and toughness are matched within a thickness range of 40 mm-65 mm, so that the application requirement of the existing hydroelectric engineering on the 800 MPa-level steel plate is met, but the strength level is still mainly concentrated at 800MPa level. Patent CN115354237a discloses a hot-rolled ultra-high strength steel plate with 1000 MPa-level tensile strength, which realizes higher strength level by improving the content of alloy elements such as Cr and Ti and combining isothermal or on-line heat treatment process, but the proposal mostly uses thin hot-rolled plate as main object, has higher requirement for process control, and has certain challenges on tissue uniformity and industrialization stability in medium-thick and thick steel plates. In addition, patent CN115386783a proposes an ultra-high strength steel plate with 1000MPa grade yield strength, and adopts multiple alloy elements to be added in a compounding way and matched with a quenching-tempering process to obtain a structure mainly comprising tempered martensite, while the strength level is higher, the alloy system is complex, the cost is higher, the dependency on the heat treatment condition is strong, and further optimization space is still available in the aspect of large-scale application of thick-specification steel plates. In summary, the prior art of the invention has been actively developed in the fields of 800 mpa-1000 mpa energy and steel plates for hydropower, but there is still a need for improvement in terms of further improving strength grade, considering tissue and performance stability under the condition of thick specification, and realizing economical and feasible industrialized preparation. Therefore, on the basis of the prior art, it is necessary to provide a high-strength steel plate for energy equipment and a preparation method thereof through alloying and microalloying collaborative design and combining reasonable process control. Disclosure of Invention The invention aims to provide a steel plate for high-strength high-toughness energy equipment and a preparation method thereof, and aims to solve the problem that the strength, toughness and welding performance of a thick steel plate for energy equipment are difficult to be compatible under high-strength conditions, and the steel plate for high-strength high-toughness energy equipment, which has the thickness of 30 mm-50 mm, the yield strength of more than or equal to 1000MPa, the tensile strength of more than or equal to 1400MPa, the impact absorption power KV2 of more than or equal to 55J at-40 ℃ and the elongation after break of more than or equal to 13%, is successfully prepared by the cooperative regulation and control of alloy compon