Method for producing 445 series stainless steel cold sheet by five-stand six-roll emulsion continuous rolling mill

Abstract

The application discloses a method for producing 445 series stainless steel cold plates by using a five-stand six-roll emulsion continuous rolling mill, which comprises the following steps: (1) distributing rolling deformation and setting rolling force, wherein the total rolling deformation is controlled within 55% to 70%, 75% to 80% of the total rolling deformation is distributed to the first three stands, 10% to 15% of the total rolling deformation is distributed to the first stand, and the rest of the total rolling deformation is distributed to the fourth and fifth stands; the rolling force of each stand is set as follows: 9000 to 10000 kN for the first stand, 10000 to 12000 kN for the second stand, 12000 to 13000 kN for the third stand, 11000 to 12000 kN for the fourth stand, and 9000 to 10000 kN for the fifth stand; and (2) adjusting the plate shape curve to a W-shaped plate shape curve. The method can be used to successfully produce 445 series stainless steel cold plates by using the five-stand six-roll emulsion continuous rolling mill, effectively avoids the risk of strip breakage, and realizes batch, efficient, stable and reliable rolling of the 445 series stainless steel cold plates, thereby being favorable to promoting the industrialized high-quality production of the 445 series stainless steel.

Description

Technical Field

[0001] This invention belongs to the field of stainless steel cold rolling technology, and particularly relates to a method for producing 445 series stainless steel cold-rolled sheets using a five-stand six-roll emulsion continuous rolling mill. It is mainly used to produce 445 series stainless steel cold-rolled sheets with finished product specifications of 1.0-2.0 mm thickness and 1000-1300 mm width. Background Technology

[0002] Ultra-pure ferritic 445 series stainless steel, represented by TTS445J2, has excellent corrosion resistance and is used in Guang'an for heat exchange tubes in harsh environments, as well as for roofs and walls of iconic coastal buildings.

[0003] Conventional ultrapure ferritic stainless steels such as the 441 series, 436 series, and 439 series are relatively easy to roll using existing continuous rolling processes because their Cr content is 17-18%, Mo content is 0-1%, yield strength Rp0.2 is 280-320 MPa, and tensile strength Rm is 440-460 MPa.

[0004] However, 445 series stainless steel has a high alloy content and high strength, with a Cr content of 21-24% and a Mo content of 1.5-2.5%. Its yield strength Rp0.2 is 350-400MPa and its tensile strength Rm is 500-550MPa. Therefore, 445 series stainless steel has high processing resistance and is very prone to brittle fracture. It also has defects such as poor plate shape. Currently, even when using a single-stand reversible rolling mill, the pass rate is less than 90%. Conventional five-stand continuous rolling production is even more difficult and cannot guarantee the smooth rolling of 445 series stainless steel. The yield is low and it is even more difficult to control a good plate shape. As a result, it is impossible to achieve mass production, high efficiency, stable and reliable rolling of 445 series stainless steel cold-rolled sheets, which affects the industrial production of 445 series stainless steel. Summary of the Invention

[0005] To address the technical problems existing in the prior art, the present invention provides a method for producing 445 series stainless steel cold-rolled sheets using a five-stand, six-roll emulsion continuous rolling mill, comprising:

[0006] (1) Distribution of rolling deformation and setting of rolling force

[0007] The total rolling deformation is controlled between 55% and 70%. 75% to 80% of the total rolling deformation is allocated to stands #1, #2, and #3. Among them, stand #1 is allocated 10% to 15% of the total rolling deformation, and stands #4 and #5 are allocated the remaining amount of the total rolling deformation.

[0008] The rolling force for each stand is set as follows: #1 stand 9000~10000kN, #2 stand 10000~12000kN, #3 stand 12000~13000kN, #4 stand 11000~12000kN, and #5 stand 9000~10000kN.

[0009] (2) Plate shape curve control

[0010] By simultaneously applying the intermediate roller and the working roller, the plate shape curve is adjusted into a W-shaped plate shape curve.

[0011] Furthermore, in the above-mentioned method for producing 445 series stainless steel cold-rolled sheets using a five-stand six-roll emulsion continuous rolling mill, the rolling deformation amount allocated to each stand is as follows: 10-15% for stand #1, 20-30% for stand #2, 20-25% for stand #3, 15-20% for stand #4, and 10-15% for stand #5.

[0012] Furthermore, in the above-mentioned method for producing 445 series stainless steel cold-rolled sheets using a five-stand six-roll emulsion continuous rolling mill, the rolling deformation amount allocated to each stand is as follows: 11% for stand #1, 23% for stand #2, 22% for stand #3, 20% for stand #4, and 14% for stand #5.

[0013] Furthermore, in the above-mentioned method for producing 445 series stainless steel cold-rolled sheets using a five-stand six-roll emulsion continuous rolling mill, the rolling forces of each stand are set as follows: 1# stand 9900kN, 2# stand 11500kN, 3# stand 12300kN, 4# stand 11100kN, and 5# stand 9500kN.

[0014] Furthermore, in the above-mentioned method for producing 445 series stainless steel cold-rolled sheets using a five-stand, six-roll emulsion continuous rolling mill, the sheet profile curve control is adjusted from the previous 25 N / mm... 2 Adjust to 20N / mm 2 .

[0015] Furthermore, in the above-mentioned method for producing 445 series stainless steel cold-rolled sheets using a five-stand six-roll emulsion continuous rolling mill, the specifications of the 445 series stainless steel cold-rolled sheets are a thickness of 1.0 to 2.0 mm and a width of 1000 to 1300 mm.

[0016] Furthermore, in the above-mentioned method for producing 445 series stainless steel cold-rolled sheets using a five-stand six-roll emulsion continuous rolling mill, the 445 series stainless steel cold-rolled sheet is a TTS445J2 ultra-pure ferritic stainless steel cold-rolled sheet.

[0017] The method for producing 445 series stainless steel cold-rolled sheets using a five-stand, six-roll emulsion continuous rolling mill of the present invention has the following advantages and beneficial effects: Through special rolling deformation distribution, rolling force setting, and sheet profile curve control technologies, 445 series stainless steel cold-rolled sheets can be successfully produced using a five-stand, six-roll emulsion continuous rolling mill, effectively avoiding the risk of strip breakage at the No. 1 and No. 2 stands. The sheet profile at the mill exit is highly flat and of good quality, with a yield rate that is more than 3% higher than that of existing technologies, fully meeting the actual needs of users. This method achieves batch, efficient, stable, and reliable rolling of 445 series stainless steel cold-rolled sheets, which is conducive to promoting the high-quality industrial production of 445 series stainless steel. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0019] Figure 1 This is a schematic diagram of the W-shaped plate profile curve used in the method of producing 445 series stainless steel cold-rolled sheets using a five-stand six-roll emulsion continuous rolling mill according to the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0021] This invention addresses the characteristics of 445 series stainless steel, such as high alloy content and high strength, and utilizes emulsion continuous rolling mills. It develops a method for producing 445 series stainless steel cold-rolled sheets using a five-stand, six-roll emulsion continuous rolling mill. Through special rolling deformation distribution, rolling force settings, and sheet profile curve control, the invention achieves high-quality industrial production of 445 series stainless steel.

[0022] Specifically, the method for producing 445 series stainless steel cold-rolled sheets using a five-stand, six-roll emulsion continuous rolling mill of the present invention includes:

[0023] 1. Distribution of rolling deformation and setting of rolling force

[0024] The total rolling deformation is controlled between 55% and 70%. To ensure the strip shape, 75% to 80% of the total rolling deformation is allocated to the No. 1, No. 2, and No. 3 stands. Among them, to prevent the steel strip from breaking brittlely at the No. 1 stand, 10% to 15% of the total rolling deformation is allocated to the No. 1 stand. The remaining amount of the total rolling deformation is allocated to the No. 4 and No. 5 stands for fine-tuning the strip shape to ensure the flatness of the strip at the mill exit.

[0025] The rolling forces for each stand are set as follows: 1st stand 9000~10000kN, 2nd stand 10000~12000kN, 3rd stand 12000~13000kN, 4th stand 11000~12000kN, and 5th stand 9000~10000kN.

[0026] 2. Plate shape curve control

[0027] The plate profile curve is adjusted to the following shape through the simultaneous action of the intermediate roller and the work roller: Figure 1 The W-shaped plate curve shown changes the plate curve from the previous 25 N / mm. 2 Adjust to 20N / mm 2 This is done to adjust the lateral pressure distribution of the steel strip, so that the extension of the edge and the middle of the steel strip at the mill exit tends to be consistent, resulting in high flatness of the strip at the mill exit.

[0028] Furthermore, in the method for producing 445 series stainless steel cold-rolled sheets using a five-stand six-roll emulsion continuous rolling mill of the present invention, the rolling deformation amount allocated to each stand is: 10-15% for stand #1, 20-30% for stand #2, 20-25% for stand #3, 15-20% for stand #4, and 10-15% for stand #5.

[0029] In one specific embodiment of the present invention, in the method for producing 445 series stainless steel cold-rolled sheet using a five-stand six-roll emulsion continuous rolling mill, the specifications of the 445 series stainless steel cold-rolled sheet are a thickness of 1.0 to 2.0 mm and a width of 1000 to 1300 mm.

[0030] The following detailed description, with reference to specific embodiments, illustrates the method for producing 445 series stainless steel cold-rolled sheets using a five-stand, six-roll emulsion continuous rolling mill according to the present invention. The following embodiments are applied to the production of TTS445J2 ultra-pure ferritic stainless steel cold-rolled sheets with a finished thickness of 1.6 mm using a five-stand, six-roll emulsion continuous rolling mill. Specific process parameters are set as shown in the table below:

[0031] Process parameters Rack #1 Rack #2 Rack #3 Rack #4 Rack #5 Rolling deformation 11％ 23％ 22％ 20％ 14％ Unit tension 110MPa 140MPa 160MPa 185MPa 200MPa Rolling pressure 9900kN 11900kN 12200kN 11800kN 9500kN tension 321.6kN 336.8kN 310.0kN 279.9kN 244.1kN emulsion concentration 1.34％ 1.34％ 1.34％ 1.87％ 1.87％

[0032] Based on actual production verification, using Embodiment 1 of the present invention, a total of 3,000 tons of TTS445J2 ultrapure ferritic stainless steel cold-rolled plates have been successfully produced in ten batches. The plates have good shape and all meet the actual usage requirements of users.

[0033] In summary, compared with the prior art, the method for producing 445 series stainless steel cold-rolled sheets using a five-stand six-roll emulsion continuous rolling mill of the present invention has the following advantages and beneficial effects: Through special rolling deformation distribution and rolling force settings, strip profile curve control and other technical means, 445 series stainless steel cold-rolled sheets can be successfully produced using a five-stand six-roll emulsion continuous rolling mill, effectively avoiding the risk of strip breakage at the 1st and 2nd stands, with high strip flatness and good strip shape at the mill exit, and a yield rate that is more than 3% higher than that of the prior art, fully meeting the actual needs of users, realizing the batch, efficient, stable and reliable rolling of 445 series stainless steel cold-rolled sheets, and promoting the high-quality industrial production of 445 series stainless steel.

[0034] It should be noted that, in this document, the term "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of producing a 445 series stainless steel cold sheet using a five stand six roll emulsion rolling mill, characterized in that, Comprise: (1) Rolling deformation distribution and rolling force setting The total rolling deformation is controlled between 55%~70%, the 1# rack, the 2# rack and the 3# rack distribute 75~80% of the total rolling deformation, and the 4# rack and the 5# rack distribute the remaining amount of the total rolling deformation, wherein the 1# rack distributes 10~15% of the total rolling deformation; The rolling force of each rack is set as: the 1# rack 9000~10000kN, the 2# rack 10000~12000kN, the 3# rack 12000~13000kN, the 4# rack 11000~12000kN, and the 5# rack 9000~10000kN; (2) Plate shape curve control The plate shape curve is adjusted to a W-shaped plate shape curve through the simultaneous action of the intermediate roll roll shifting and the work roll bending.

2. The method of producing 445 series stainless steel cold sheet using the five stand six roll emulsion rolling mill according to claim 1, wherein, In the plate profile control, the plate profile curve is adjusted from the previous 25 N / mm 2 to 20 N / mm 2 .

3. The method of producing 445 series stainless steel cold sheet using the five-stand six-roll emulsion rolling mill according to claim 1 or 2, characterized in that, The specification of the 445 series stainless steel cold plate is thickness 1.0~2.0mm, width 1000~1300mm.

4. The method of producing 445 series stainless steel cold sheet according to claim 3, wherein The 445 series stainless steel cold plate is a TTS445J2 ultra-pure ferritic stainless steel cold plate.

Images