Rolling method of extra-thick wide offshore wind power steel

Abstract

The invention discloses a rolling method of extra-thick wide offshore wind power steel, which relates to the technical field of metallurgy and comprises the following steps: heating a steel billet; the heated steel billet is subjected to descaling; the steel billet is subjected to two-stage controlled rolling, the reduction rate of each pass of three passes after rough rolling is controlled to be larger than 6%, the torque of each pass of at least two passes after rough rolling is controlled to be larger than 8488 kNm, the thickness of an intermediate billet is controlled to be larger than or equal to 2.0 times of the thickness of a finished product, the initial rolling temperature of finish rolling is controlled to be 720-760 DEG C, and the finish rolling temperature is controlled to be 730-770 DEG C; and the rolled piece is subjected to ACC cooling treatment. It is guaranteed that the yield strength of the extra-thick wide offshore wind power steel is larger than or equal to 385 MPa, the tensile strength ranges from 490 MPa to 660 MPa, the ductility is larger than or equal to 17%, the longitudinal impact energy at the 1 / 4 position and the 1 / 2 position of the thickness at the temperature of-50 DEG C is larger than or equal to 27 J, the transverse impact energy is larger than or equal to 16 J, and the performance requirement of the offshore wind power steel is met.

Description

Technical Field

[0001] The present invention relates to the technical field of metallurgy, and in particular to a method for rolling extra-thick and wide offshore wind power steel. Background Art

[0002] With the development of offshore wind turbines in deeper waters and larger scale, the development of low-cost, high-performance steel for offshore wind towers has become a critical issue that needs to be urgently addressed in the marine sector. To meet the needs of larger wind turbines and reduce the amount of welding, offshore wind power steel requires high strength, corrosion resistance, and ease of welding, while pursuing single-plate heavy weight, wide width, and extra thickness. S460ML, as a low-alloy, high-strength plate that meets the European standard (EN10025), has excellent low-temperature toughness and welding stability, making it the preferred structural material for major engineering projects in the low-temperature field. This type of steel plate has a high strength level, strict impact requirements, and is very difficult to produce. Therefore, a method for rolling extra-thick and wide-width offshore wind power steel is urgently needed. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a rolling method for ultra-thick and wide offshore wind power steel.

[0004] In order to solve the above technical problems, the technical solutions of the present invention are as follows: A rolling method for extra-thick and wide offshore wind power steel, comprising: heating the steel billet; Descaling the heated steel billet; The steel slab is subjected to two-stage controlled rolling, wherein the reduction rate of each of the three passes after rough rolling is controlled to be greater than 6%, the torque of each of at least two passes after rough rolling is controlled to be greater than 8488 kNm, the thickness of the intermediate slab is controlled to be greater than or equal to 2.0 times the thickness of the finished product, the starting rolling temperature of the finishing rolling is controlled to be 720-760°C, and the final rolling temperature is controlled to be 730-770°C; The rolled piece is subjected to ACC cooling treatment.

[0005] As a preferred solution of the rolling method of the ultra-thick and wide offshore wind power steel of the present invention, the heating of the steel billet comprises: The steel billet is heated at ultra-low temperature and the furnace temperature is controlled at 1020±10℃.

[0006] As a preferred solution of the rolling method of the ultra-thick and wide offshore wind power steel of the present invention, wherein: the controlling of the furnace temperature to 1020±10°C includes: The heating temperature of the second and third heating sections of the heating furnace is controlled not to be higher than 1040°C, and the heating temperature of the soaking section is controlled not to be higher than 1030°C.

[0007] As a preferred solution of the rolling method of the ultra-thick and wide offshore wind power steel of the present invention, the heating of the steel billet further comprises: The total time of the steel billet in the furnace is controlled to be 13.0-17.0 min / cm, the total heating time of the second heating section and the third heating section is greater than 240 min, and the soaking section time is greater than 1.4 min / cm.

[0008] As a preferred solution of the rolling method of the ultra-thick and wide offshore wind power steel of the present invention, in the two-stage controlled rolling, the reduction ratio of the thickness of the steel billet to the finished product is controlled to be 4.18.

[0009] As a preferred solution of the rolling method of the extra-thick and wide-width offshore wind power steel described in the present invention, wherein: in the two-stage controlled rolling, the total rolling passes are controlled to be 27 passes, the roughing stage is 15 passes, and the number of passes with a scheduled torque of 7500-8400 kNm is greater than or equal to three, the scheduled torque of the last pass in the roughing stage is controlled to be 50000-70000 kNm, the finishing stage is 11 passes, and the torque of the last pass in the scheduled finishing stage is less than or equal to 50000 kNm, and the scheduled rolling force is less than or equal to 60000 kN.

[0010] As a preferred solution of the rolling method of the ultra-thick and wide offshore wind power steel of the present invention, in the two-stage controlled rolling, the roller diameter is controlled to be 1110-1160 mm.

[0011] As a preferred solution of the rolling method of the ultra-thick and wide offshore wind power steel of the present invention, the ACC cooling treatment of the rolled piece includes: The cooling temperature is controlled to be 300-340℃, and the cooling rate is 5.8℃ / s.

[0012] The beneficial effects of the present invention are: The present invention ensures that the yield strength of the 110*4193mm S460ML extra-thick wide offshore wind power steel is greater than or equal to 385MPa, the tensile strength is 490-660MPa, the elongation is ≥17%, the longitudinal impact energy at 1 / 4 and 1 / 2 of the thickness at -50°C is ≥27J, and the transverse impact energy is ≥16J, meeting the performance requirements of offshore wind power steel. DETAILED DESCRIPTION

[0013] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific implementation methods.

[0014] The present application provides a method for rolling ultra-thick and wide offshore wind power steel, which specifically comprises the following steps: Step S101: heating the steel billet.

[0015] Specifically, TMCP rolling of S460ML utilizes ultra-low temperature heating, with a controlled exit temperature of 1020±10°C and a total furnace time of 13.0-17.0 min / cm. The combined heating time for the second and third heating stages exceeds 240 minutes, with a soaking time exceeding 1.4 min / cm. The third heating stage is first heated to 1040°C, and then cooled to 1030°C in the soaking stage. This improves low-temperature heating temperature uniformity, allowing alloying elements in the steel to fully dissolve, ensuring uniform composition and performance of the final product.

[0016] Step S102: descaling the heated steel billet.

[0017] Specifically, high-pressure water is used to descale the steel billet after it leaves the heating furnace.

[0018] Step S103: The steel billet is subjected to two-stage controlled rolling, wherein the reduction rate of each of the three passes after rough rolling is controlled to be greater than 6%, the torque of each of at least two passes after rough rolling is controlled to be greater than 8488 kNm, the thickness of the intermediate billet is controlled to be greater than or equal to 2.0 times the thickness of the finished product, the starting rolling temperature of the finishing rolling is controlled to be 720-760°C, and the final rolling temperature is controlled to be 730-770°C.

[0019] Specifically, in this rolling process, small-diameter rolls are used, the upper limit of the secondary model torque is increased, the maximum torque of the pressing procedure is arranged to be 2.0 times the rated torque, and the maximum updated torque of the rolling process is 2.1 times the rated torque.

[0020] In this embodiment, ultra-low temperature rolling (second stage rolling start temperature 745°C) is used, the reduction ratio of the billet to the finished product thickness is 4.18, the total number of rolling passes is 27, the roughing stage is 15 passes, the torque for more than three passes is arranged to be 7500-8400 kNm, and the torque for the last pass in the roughing stage is arranged to be 50000-70000 kNm; the finishing stage is 11 passes, the torque for the last pass is arranged to be no more than 50000 kNm, and the rolling force is arranged to be no more than 60000 kN.

[0021] It should be noted that a margin of 2 to 5 mm is reserved for the reduction of the widening pass and the roughing pass to meet the self-learning update of the secondary rolling model and the stability of the reduction schedule. The rolling reduction schedule is arranged as follows:

[0022] Step S104: performing ACC cooling treatment on the rolled piece.

[0023] Specifically, after finishing rolling, ACC accelerated cooling is performed, the cooling temperature is 300-340°C, and the cooling rate is 5.8°C / s.

[0024] The above method is used to ensure that the yield strength of 110*4193mm S460ML extra-thick wide offshore wind power steel is greater than or equal to 385MPa, the tensile strength is 490-660MPa, the elongation is ≥17%, the longitudinal impact energy at 1 / 4 and 1 / 2 of the thickness at -50℃ is ≥27J, and the transverse impact energy is ≥16J.

[0025] In addition to the above embodiments, the present invention may also have other implementation methods; any technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present invention.

Claims

1. A rolling method for extra-thick and wide offshore wind power steel, characterized by: include: heating the steel billet; Descaling the heated steel billet; The steel slab is subjected to two-stage controlled rolling, wherein the reduction rate of each of the three passes after rough rolling is controlled to be greater than 6%, the torque of each of at least two passes after rough rolling is controlled to be greater than 8488 kNm, the thickness of the intermediate slab is controlled to be greater than or equal to 2.0 times the thickness of the finished product, the starting rolling temperature of the finishing rolling is controlled to be 720-760°C, and the final rolling temperature is controlled to be 730-770°C; The rolled piece is subjected to ACC cooling treatment.

2. The rolling method for extra-thick and wide offshore wind power steel according to claim 1, characterized in that: The heating of the steel billet comprises: The steel billet is heated at ultra-low temperature and the furnace temperature is controlled at 1020±10℃.

3. The rolling method of extra-thick and wide offshore wind power steel according to claim 2, characterized in that: The control of the furnace temperature to 1020±10°C includes: The heating temperature of the second and third heating sections of the heating furnace is controlled not to be higher than 1040°C, and the heating temperature of the soaking section is controlled not to be higher than 1030°C.

4. The rolling method of extra-thick and wide offshore wind power steel according to claim 3, characterized in that: The heating of the steel billet further comprises: The total time of the steel billet in the furnace is controlled to be 13.0-17.0 min / cm, the total heating time of the second heating section and the third heating section is greater than 240 min, and the soaking section time is greater than 1.4 min / cm.

5. The rolling method of extra-thick and wide offshore wind power steel according to claim 1, characterized in that: During the two-stage controlled rolling, the reduction ratio of the billet to the finished product thickness is controlled to be 4.

18.

6. The rolling method of extra-thick and wide offshore wind power steel according to claim 1, characterized in that: In the two-stage controlled rolling, the total rolling passes are controlled to be 27 passes, the roughing stage is 15 passes, and the number of passes with a scheduled torque of 7500 to 8400 kNm is greater than or equal to three, the scheduled torque of the last pass in the roughing stage is controlled to be 50,000 to 70,000 kNm, the finishing stage is 11 passes, and the scheduled torque of the last pass in the finishing stage is less than or equal to 50,000 kNm, and the scheduled rolling force is less than or equal to 60,000 kN.

7. The rolling method of extra-thick and wide offshore wind power steel according to claim 1, characterized in that: In the two-stage controlled rolling, the roller diameter is controlled to be 1110 to 1160 mm.

8. The rolling method of extra-thick and wide offshore wind power steel according to claim 1, characterized in that: The ACC cooling treatment of the rolled piece comprises: The cooling temperature is controlled to be 300-340℃, and the cooling rate is 5.8℃ / s.

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