Galvanized aluminum magnesium cold-rolled substrate rolling schedule design method considering thickness difference quality and surface quality

Abstract

The invention discloses a zinc-aluminum-magnesium-plated cold-rolled substrate rolling schedule design method considering thickness difference quality and surface quality, which is characterized in that relevant parameters are set according to steel grade strength, and the method comprises the steps of steel grade division, pressing schedule formulation of each rack, tension parameter formulation of each rack and roll bending force upper limit value setting. And putting into a cold rolling production line to execute rolling according to set parameters. Compared with the prior art, the thickness difference quality and the surface quality can be considered, the rolling process of the type of products is designed, and then stable production of the type of products is assisted.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgical engineering, and in particular relates to a rolling procedure design method for a galvanized aluminum-magnesium cold-rolled substrate taking both thickness difference quality and surface quality into consideration. Background Art

[0002] Zinc-aluminum-magnesium products have high strength and are prone to difficult processing problems caused by differences in deformation resistance during the production of cold-rolled substrates. In this context, substrate thickness defects and strip surface defects have become the main quality defects faced by the production of hot-dip galvanized aluminum-magnesium products. Most of the existing research is carried out around the alloy composition design of zinc-aluminum-magnesium substrates. By developing reasonable alloy compositions, the difficulty of cold rolling production is reduced from the perspective of material deformation resistance. For example, the "a hot-dip galvanized aluminum-magnesium high-strength steel, preparation method and application", "high-strength zinc-aluminum-magnesium coated steel plate with good surface quality and its manufacturing method" and "a hot-dip galvanized aluminum-magnesium high-strength steel and its manufacturing method" retrieved by the present invention have all developed different alloy composition systems to enhance the control effect of thickness and surface quality from the source.

[0003] However, the cold rolling preparation of zinc-aluminum-magnesium substrates is not completed by a single rolling process. It often requires multiple passes or continuous rolling on multiple stands, that is, multiple deformations to reach the target thickness. Due to the different deformation amounts in each time, the work hardening of the strip after each rolling is also different. For this reason, it is urgent to provide a rolling strategy for zinc-aluminum-magnesium substrates of different grades, taking into account the thickness difference quality and surface quality, designing the rolling process of such products, and then assisting the stable production of this type of products. Summary of the invention

[0004] The purpose of the present invention is to provide a rolling procedure design method for a galvanized aluminum-magnesium cold-rolled substrate that takes into account both thickness difference quality and surface quality, so as to solve the problem that it is difficult to jointly control the thickness difference defects and surface quality defects of the galvanized aluminum-magnesium cold-rolled substrate by existing technical means, thereby providing technical support for the high-quality and stable production of such strips.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The present invention provides a rolling procedure design method for a galvanized aluminum-magnesium cold-rolled substrate taking both thickness difference quality and surface quality into consideration, comprising the following steps:

[0007] Step S1, classifying the steel types according to the strength of the strip steel base material, the strength definition interval length is 100 MPa, and is divided into three strength value intervals [300 MPa, 400 MPa], [400 MPa, 500 MPa] and [500 MPa, 600 MPa];

[0008] Step S2: According to the strength difference of the base material, formulate the pressing procedures for each rack as follows:

[0009] (1) For the zinc-aluminum-magnesium base material with a strength range of [300MPa, 400MPa], the reduction rate of each pass is set as follows:

[0010] ① F1 stand presses down 32%: during the first rolling process, the material thickness is reduced by 30%;

[0011] ②F2 stand presses down 33%: during the second rolling process, the material thickness is reduced by 30%;

[0012] ③F3 stand presses down 29%: During the third rolling process, the material thickness is reduced by 25%;

[0013] ④F4 stand presses down 22%: During the fourth rolling process, the material thickness is reduced by 20%;

[0014] ⑤F5 stand presses down 1%: During the last rolling process, the material thickness is reduced by 2%;

[0015] To ensure the final thickness and surface flatness;

[0016] (2) For the zinc-aluminum-magnesium base material with a strength range of [400MPa, 500MPa], the reduction rate of each pass is set as follows:

[0017] ① F1 stand presses down 18.5%: During the first rolling process, the material thickness is reduced by 18.5%;

[0018] ②F2 stand presses down 19%: During the second rolling process, the material thickness is reduced by 19%;

[0019] ③F3 stand presses down 18.8%: During the third rolling process, the material thickness is reduced by 18.8%;

[0020] ④F4 stand presses down 16.4%: During the fourth rolling process, the material thickness is reduced by 16.4%;

[0021] ⑤F5 stand presses down 1.0%: During the last rolling process, the material thickness is reduced by 1.0%;

[0022] To ensure the final thickness and surface flatness;

[0023] (3) For the zinc-aluminum-magnesium base material with a strength range of [500MPa, 600MPa], the reduction rate of each pass is set as follows:

[0024] ① F1 stand presses down 18%: during the first rolling process, the material thickness is reduced by 18%;

[0025] ②F2 stand presses down 19%: During the second rolling process, the material thickness is reduced by 19%;

[0026] ③F3 stand presses down 19.7%: During the third rolling process, the material thickness is reduced by 19.7%;

[0027] ④F4 stand presses down 14%: During the fourth rolling process, the material thickness is reduced by 14%;

[0028] ⑤F5 stand presses down 1.0%: During the last rolling process, the material thickness is reduced by 1.0%;

[0029] To ensure the final thickness and surface flatness;

[0030] Step S3: According to the difference in base material strength, formulate the tension parameter regulations for each rack as follows:

[0031] (1) For the zinc-aluminum-magnesium base material with a strength range of [300MPa, 400MPa], the tension of each rack is set as follows: F1 rack: 7.3 (10N / mm 2 ); F2 frame: 21(10N / mm 2 ); F3 frame: 24 (10N / mm 2 ); F4 frame: 25.5 (10N / mm 2 ); F5 frame: 26 (10N / mm 2 ); discharge end: 7.5(10N / mm 2 );

[0032] (2) For the zinc-aluminum-magnesium base material with a strength range of [400MPa, 500MPa], the tension of each rack is set as follows: F1 rack: 5.0 (10N / mm 2 ); F2 frame: 12(10N / mm 2 ); F3 frame: 13 (10N / mm 2 ); F4 frame: 14 (10N / mm 2 ); F5 frame: 15(10N / mm 2 ); discharge end: 5.3(10N / mm 2 );

[0033] (3) For the zinc-aluminum-magnesium base material with a strength range of [500MPa, 600MPa], the tension of each rack is set as follows: F1 rack: 5.2 (10N / mm 2 ); F2 frame: 18 (10N / mm 2 ); F3 frame: 19 (10N / mm 2 ); F4 frame: 20(10N / mm 2 ); F5 frame: 20.5 (10N / mm 2 ); discharge end: 6.0(10N / mm 2 );

[0034] Step S4: according to the difference in base material strength, set the upper limit of the bending roller force as follows:

[0035] (1) For the zinc-aluminum-magnesium base material with a strength range of [300MPa, 400MPa], in order to ensure the flatness during rolling, the working roll and bending roll both use a bending roll force of 23 (10KN / ch);

[0036] (2) For zinc-aluminum-magnesium base materials with a strength range of [400MPa, 500MPa], in order to ensure flatness during rolling, the working roll and bending roll use a bending roll force of 18-23 (10KN / ch);

[0037] (3) For the zinc-aluminum-magnesium base material with a strength range of [500MPa, 600MPa], in order to ensure the flatness during rolling, the working roll and bending roll use a bending roll force of 18-21 (10KN / ch);

[0038] Step S5: For different base materials, rolling is performed according to the above scheme.

[0039] Furthermore, by optimizing rolling parameters and process control, the surface quality and mechanical properties of the product were significantly improved.

[0040] Compared with the prior art, the beneficial technical effects of the present invention are: BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention will be further described below in conjunction with the accompanying drawings.

[0042] Figure 1 A schematic flow chart of a method for designing a rolling procedure for a galvanized aluminum-magnesium cold-rolled substrate that takes both thickness difference quality and surface quality into consideration in the present invention;

[0043] Figure 2 Rolling schedule setting for S350GD+ZAM;

[0044] Figure 3 Rolling schedule setting for S420GD+ZAM;

[0045] Figure 4 Rolling schedule setting for S550GD+ZAM. DETAILED DESCRIPTION

[0046] The process of the present invention is further described below in conjunction with specific implementation cases.

[0047] In order to fully describe the technical content, structural features, objectives and effects of the present invention, the following is a detailed description with reference to the accompanying drawings.

[0048] The present invention provides a method for designing a rolling procedure for a galvanized aluminum-magnesium cold-rolled substrate that takes both thickness difference quality and surface quality into consideration, and is implemented based on a cold rolling mill in a steel plant. The specific implementation of the present invention is as follows:

[0049] Embodiment 1:

[0050] Taking S350GD+ZAM as an example, the rolling parameters are set according to the process of the present invention as follows: Figure 2 As shown in the figure, the quality of the strip steel after rolling was analyzed, and the surface quality and mechanical properties of the product were significantly improved by optimizing the rolling parameters and process control.

[0051] Embodiment 2:

[0052] Taking S420GD+ZAM as an example, the rolling parameters are set according to the process of the present invention as follows: Figure 3 As shown in the figure, the quality of the strip steel after rolling was analyzed, and the surface quality and mechanical properties of the product were significantly improved by optimizing the rolling parameters and process control.

[0053] Embodiment three:

[0054] Taking S550GD+ZAM as an example, the rolling parameters are set according to the process of the present invention as follows: Figure 4 As shown in the figure, the quality of the strip steel after rolling was analyzed, and the surface quality and mechanical properties of the product were significantly improved by optimizing the rolling parameters and process control.

[0055] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A rolling procedure design method for galvanized aluminum-magnesium cold-rolled substrate taking into account both thickness difference quality and surface quality, characterized in that: The steps include: Step S1, classifying the steel types according to the strength of the strip steel base material, the strength definition interval length is 100 MPa, and is divided into three strength value intervals [300 MPa, 400 MPa], [400 MPa, 500 MPa] and [500 MPa, 600 MPa]; Step S2: According to the strength difference of the base material, formulate the pressing procedures for each rack as follows: (1) For the zinc-aluminum-magnesium base material with a strength range of [300MPa, 400MPa], the reduction rate of each pass is set as follows: ① F1 stand presses down 32%: during the first rolling process, the material thickness is reduced by 30%; ②F2 stand presses down 33%: during the second rolling process, the material thickness is reduced by 30%; ③F3 stand presses down 29%: During the third rolling process, the material thickness is reduced by 25%; ④F4 stand presses down 22%: During the fourth rolling process, the material thickness is reduced by 20%; ⑤F5 stand presses down 1%: During the last rolling process, the material thickness is reduced by 2%; To ensure the final thickness and surface flatness; (2) For the zinc-aluminum-magnesium base material with a strength range of [400MPa, 500MPa], the reduction rate of each pass is set as follows: ① F1 stand presses down 18.5%: During the first rolling process, the material thickness is reduced by 18.5%; ②F2 stand presses down 19%: during the second rolling process, the material thickness is reduced by 19%; ③F3 stand presses down 18.8%: During the third rolling process, the material thickness is reduced by 18.8%; ④F4 stand presses down 16.4%: During the fourth rolling process, the material thickness is reduced by 16.4%; ⑤F5 stand presses down 1.0%: During the last rolling process, the material thickness is reduced by 1.0%; To ensure the final thickness and surface flatness; (3) For the zinc-aluminum-magnesium base material with a strength range of [500MPa, 600MPa], the reduction rate of each pass is set as follows: ① F1 stand presses down 18%: during the first rolling process, the material thickness is reduced by 18%; ②F2 stand presses down 19%: During the second rolling process, the material thickness is reduced by 19%; ③F3 stand presses down 19.7%: During the third rolling process, the material thickness is reduced by 19.7%; ④F4 stand presses down 14%: During the fourth rolling process, the material thickness is reduced by 14%; ⑤F5 stand presses down 1.0%: During the last rolling process, the material thickness is reduced by 1.0%; To ensure the final thickness and surface flatness; Step S3: According to the difference in base material strength, formulate the tension parameter regulations for each rack as follows: (1) For the zinc-aluminum-magnesium base material with a strength range of [300MPa, 400MPa], the tension of each rack is set as follows: F1 rack: 7.3 (10N / mm 2 ); F2 frame: 21(10N / mm 2 ); F3 frame: 24 (10N / mm 2 ); F4 frame: 25.5 (10N / mm 2 ); F5 frame: 26 (10N / mm 2 ); discharge end: 7.5(10N / mm 2 ); (2) For the zinc-aluminum-magnesium base material with a strength range of [400MPa, 500MPa], the tension of each rack is set as follows: F1 rack: 5.0 (10N / mm 2 ); F2 frame: 12(10N / mm 2 ); F3 frame: 13 (10N / mm 2 ); F4 frame: 14 (10N / mm 2 ); F5 frame: 15(10N / mm 2 ); discharge end: 5.3(10N / mm 2 ); (3) For the zinc-aluminum-magnesium base material with a strength range of [500MPa, 600MPa], the tension of each rack is set as follows: F1 rack: 5.2 (10N / mm 2 ); F2 frame: 18 (10N / mm 2 ); F3 frame: 19 (10N / mm 2 ); F4 frame: 20(10N / mm 2 ); F5 frame: 20.5 (10N / mm 2 ); discharge end: 6.0(10N / mm 2 ); Step S4: according to the difference in base material strength, set the upper limit of the bending roller force as follows: (1) For the zinc-aluminum-magnesium base material with a strength range of [300MPa, 400MPa], in order to ensure the flatness during rolling, the working roll and bending roll both use a bending roll force of 23 (10KN / ch); (2) For zinc-aluminum-magnesium base materials with a strength range of [400MPa, 500MPa], in order to ensure flatness during rolling, the working roll and bending roll use a bending roll force of 18-23 (10KN / ch); (3) For the zinc-aluminum-magnesium base material with a strength range of [500MPa, 600MPa], in order to ensure the flatness during rolling, the working roll and bending roll use a bending roll force of 18-21 (10KN / ch); Step S5: For different base materials, rolling is performed according to the above scheme.

2. The method for designing a rolling procedure for a galvanized aluminum-magnesium cold-rolled substrate taking both thickness difference quality and surface quality into consideration according to claim 1, characterized in that: By optimizing rolling parameters and process control, the surface quality and mechanical properties of the products are significantly improved.

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