High-strength aluminum-plated zinc plate produced by improved Sendzimir method and process of high-strength aluminum-plated zinc plate

Abstract

The invention discloses a high-strength aluminum-zinc plated plate produced by an improved Sendzimir method and a process thereof, which belong to the technical field of metal plates and comprise the steps of acid pickling, cold rolling, aluminum-zinc hot-dip plating, high-temperature annealing, rapid cold rolling and finishing. The process standard in a whole set of acid pickling, cold rolling and aluminum-zinc plating integrated production process system is precisely planned, and the production requirements of the high-strength aluminum-zinc plating plate are precisely met. And through a fine process control means, the high stability and quality consistency of the 0.95 mm thickness grade aluminum-plated zinc plate in performance are ensured, and the tensile strength is always stabilized at 700 Mpa or above. According to the production technology, stable operation of the process is successfully achieved, the advantages that the technological process is simple and clear, and production management and control are convenient and efficient are shown, and due to low cost control, the production technology becomes an optimal scheme for production of the 0.95 mm-thickness-level high-strength aluminum-zinc-plated plate.

Description

Technical Field

[0001] The invention relates to the technical field of metal plates, and in particular to a high-strength aluminum-zinc plate produced by a modified Sendzimir process and a process thereof. Background Art

[0002] In recent years, with the rapid development of my country's structural parts industry, the technical requirements of the structural parts market for thin specifications and high-strength specifications are also developing by leaps and bounds. The strength required for structural parts is also continuously increasing, gradually transitioning from the early 1.5-2.5 mm to a thinner 0.8-1.5 mm, that is, using higher strength to replace thicker building materials to reduce practical costs, to reduce the practical costs of structural parts manufacturers. Therefore, downstream structural parts manufacturers have been conducting research and development on high-strength aluminum-zinc-plated parts to reduce their practical costs.

[0003] For example, Chinese patent CN115198204B discloses zinc-aluminum-magnesium coated high-strength steel for new energy storage cabinets, its steel matrix and preparation method, which belongs to the field of steel preparation technology, and selectively adds micro-alloy elements Nb, V and Ti. In the process of steel preparation, Nb, V and Ti are precipitated in the form of carbides, which can significantly improve the hardness and strength of the ferrite structure, reduce the hardness difference between ferrite and tempered troostite, and are conducive to obtaining a higher yield strength ratio and excellent bending performance. The thickness of the steel is between 2.5mm-3.0mm, the tensile strength is ≥800MPa, and the yield strength ratio is ≥0.91. Compared with traditional thick-gauge low-alloy structural steel, it has higher strength and stiffness.

[0004] Although the above patent achieves a tensile strength of more than 800Mpa, the thickness of the steel in the above patent is between 2.5mm-3.0mm, and the material cost is relatively high; in addition, in order to improve the strength in the above patent, expensive micro-alloy elements Nb, V and Ti are added, which further increases the cost.

[0005] Based on this, the present invention designs a high-strength galvanized aluminum sheet produced by a modified Sendzimir process and a process thereof to solve the above problems. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, the present invention provides a high-strength aluminum-zinc coated sheet produced by a modified Sendzimir process and a process thereof.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A process for producing high-strength galvanized steel sheet by using a modified Sendzimir process, comprising pickling, cold rolling, hot-dip galvanizing, high-temperature annealing, rapid cold rolling and skin pass; The specific steps include: 1) Pickling the substrate at a concentration of 15-25% hydrochloric acid, a pickling temperature of 70-90°C and a pickling speed of 130-180m / min; 2) When the roller diameter is 400-430mm, the concentration of rolling oil is ≥4%, and the post tension is 80-160N / mm 2 The pickled substrate is cold rolled under the condition of 3) The cold-rolled substrate is passed through an aluminum-zinc liquid at 500-600°C to plate the metal aluminum-zinc on the surface of the substrate; 4) The aluminum-zinc plated substrate is annealed at ≥870°C, and after annealing, the temperature of the first zone and the second zone of the cooling section is controlled to be reduced to ≤600°C for rolling, and is subjected to skin finishing under the conditions of skin finishing force ≥150 tons and elongation ≥0.15%, thereby obtaining a high-strength aluminum-zinc plate.

[0008] Furthermore, step 1) is specifically: pickling the substrate at a concentration of 18-20% hydrochloric acid, a pickling temperature of 80-82° C., and a pickling speed of 150-160 m / min.

[0009] Furthermore, step 2) is specifically as follows: when the roller diameter is 400-420mm, the concentration of rolling oil is ≥4%, and the post tension is 100-120N / mm 2 The pickled substrate is cold rolled under the conditions of.

[0010] Furthermore, step 3) is specifically as follows: passing the cold-rolled substrate through an aluminum-zinc liquid at 530-560° C. to plate metal aluminum-zinc on the surface of the substrate.

[0011] Furthermore, in the step 4), after annealing, the temperature of the first zone and the second zone of the cooling section is controlled to be lowered to ≤ 600°C, and rolling is performed under the action of a working roll bending force of more than 20 tons and an intermediate roll bending force of more than 8 tons.

[0012] Furthermore, the substrate is made of 25MnTiB hot-rolled coil with a Mn content of ≥1.2% and a Cr content of ≥0.15%.

[0013] Furthermore, the thickness of the high-strength galvanized aluminum sheet is ≥0.95 mm.

[0014] A high-strength galvanized steel sheet is prepared by the process for producing high-strength galvanized steel sheet by using the improved Sendzimir process.

[0015] Compared with the prior art, the present invention has the following beneficial effects: the present invention accurately plans a set of process standards in the integrated production process system of pickling, cold rolling and galvanizing, which accurately meets the production requirements of high-strength galvanized sheet materials. Through sophisticated process control means, the high stability and quality consistency of 0.95mm thick galvanized sheet materials are ensured, and the tensile strength is always stable at above 700Mpa. This production process not only successfully realizes the stable operation of the process, but also demonstrates the advantages of concise and clear process flow, convenient and efficient production control, and its low cost control makes it the preferred solution for the production of 0.95mm thick high-strength galvanized sheet materials. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] Embodiment 1: This embodiment provides a high-strength galvanized sheet produced by a modified Sendzimir process, including pickling, cold rolling, hot-dip galvanizing, high-temperature annealing, rapid cold rolling and skin pass; The specific steps include: 1) Pickling the substrate at a concentration of 25% hydrochloric acid, a pickling temperature of 90°C and a pickling speed of 180m / min; The substrate is made of 25MnTiB hot-rolled coil with a Mn content of ≥1.2% and a Cr content of ≥0.15%; 2) When the roll diameter is 430mm, the concentration of rolling oil is 4%, and the post tension is 160N / mm 2 The pickled substrate is cold rolled under the condition of 3) The cold-rolled substrate is passed through a 600°C aluminum-zinc liquid to plate the metal aluminum-zinc on the surface of the substrate; 4) The aluminum-zinc plated substrate is annealed at a temperature above 870°C. After annealing, the temperature of the first and second zones of the cooling section is controlled to drop to 600°C. The substrate is rolled under a working roll bending force of 20 tons and an intermediate roll bending force of 8 tons. The substrate is smoothed under a smoothing force of 150 tons and an elongation of 0.15%. A quarter-wave plate is used to control the plate shape on both sides of the substrate, thereby obtaining a high-strength aluminum-zinc plate with a thickness of 0.95 mm.

[0018] Embodiment 2: This embodiment provides a high-strength galvanized sheet produced by a modified Sendzimir process, including pickling, cold rolling, hot-dip galvanizing, high-temperature annealing, rapid cold rolling and skin pass; The specific steps include: 1) Pickling the substrate at a concentration of 15% hydrochloric acid, a pickling temperature of 70°C and a pickling speed of 130m / min; The substrate is made of 25MnTiB hot-rolled coil with a Mn content of ≥1.2% and a Cr content of ≥0.15%; 2) When the roll diameter is 400mm, the concentration of rolling oil is 5%, and the post tension is 80N / mm 2 The pickled substrate is cold rolled under the condition of 3) The cold-rolled substrate is passed through a 500°C aluminum-zinc liquid to plate the metal aluminum-zinc on the surface of the substrate; 4) The aluminum-zinc plated substrate is annealed at 880°C. After annealing, the temperature of the first and second zones of the cooling section is controlled to drop to 580°C. The substrate is rolled under a working roll bending force of 21 tons and an intermediate roll bending force of 9 tons. The substrate is smoothed under a smoothing force of 160 tons and an elongation of 0.2%. A quarter-wave plate is used to control the plate shape on both sides of the substrate to obtain a high-strength aluminum-zinc plate with a thickness of 0.98 mm.

[0019] Embodiment 3: This embodiment provides a high-strength galvanized sheet produced by a modified Sendzimir process, including pickling, cold rolling, hot-dip galvanizing, high-temperature annealing, rapid cold rolling and skin pass; The specific steps include: 1) Pickling the substrate at a concentration of 18% hydrochloric acid, a pickling temperature of 80°C and a pickling speed of 150m / min; The substrate is made of 25MnTiB hot-rolled coil with a Mn content of ≥1.2% and a Cr content of ≥0.15%; 2) When the roll diameter is 420mm, the concentration of rolling oil is 6%, and the post tension is 80N / mm 2 The pickled substrate is cold rolled under the condition of 3) The cold-rolled substrate is passed through an aluminum-zinc liquid at 530°C to plate the metal aluminum-zinc on the surface of the substrate; 4) The aluminum-zinc plated substrate was annealed at 875°C. After annealing, the temperature of the first and second zones of the cooling section was controlled to drop to 590°C. The substrate was rolled under a working roll bending force of 22 tons and an intermediate roll bending force of 8 tons. The substrate was smoothed under a smoothing force of 158 tons and an elongation of 0.17%. A quarter-wave plate was used to control the plate shape on both sides of the substrate to obtain a high-strength aluminum-zinc plate with a thickness of 1.17 mm.

[0020] Embodiment 4: This embodiment provides a high-strength galvanized sheet produced by a modified Sendzimir process, including pickling, cold rolling, hot-dip galvanizing, high-temperature annealing, rapid cold rolling and skin pass; The specific steps include: 1) The substrate was pickled at a concentration of 24% hydrochloric acid, a pickling temperature of 88°C and a pickling speed of 170m / min; The substrate is made of 25MnTiB hot-rolled coil with a Mn content of ≥1.2% and a Cr content of ≥0.15%; 2) When the roll diameter is 425mm, the concentration of rolling oil is 5%, and the post tension is 150N / mm 2 The pickled substrate is cold rolled under the condition of 3) The cold-rolled substrate is passed through an aluminum-zinc liquid at 580°C to plate the metal aluminum-zinc on the surface of the substrate; 4) The aluminum-zinc plated substrate is annealed at 890°C. After annealing, the temperature of the first and second zones of the cooling section is controlled to drop to 600°C. The substrate is rolled under a working roll bending force of 20 tons and an intermediate roll bending force of 9 tons. The substrate is smoothed under a smoothing force of 160 tons and an elongation of 0.15%. A quarter-wave plate is used on both sides of the substrate to control the plate shape, thereby obtaining a high-strength aluminum-zinc plate with a thickness of 1.26 mm.

[0021] Embodiment 5: This embodiment provides a high-strength galvanized sheet produced by a modified Sendzimir process, including pickling, cold rolling, hot-dip galvanizing, high-temperature annealing, rapid cold rolling and skin pass; The specific steps include: 1) The substrate was pickled at a concentration of 23% hydrochloric acid, a pickling temperature of 86°C and a pickling speed of 180 m / min; The substrate is made of 25MnTiB hot-rolled coil with a Mn content of ≥1.2% and a Cr content of ≥0.15%; 2) When the roller diameter is 410mm, the concentration of rolling oil is 5%, and the post tension is 140N / mm 2 The pickled substrate is cold rolled under the condition of 3) The cold-rolled substrate is passed through an aluminum-zinc liquid at 570°C to plate the metal aluminum-zinc on the surface of the substrate; 4) The aluminum-zinc plated substrate is annealed at 880°C. After annealing, the temperature of the first and second zones of the cooling section is controlled to drop to 600°C. The substrate is rolled under a working roll bending force of 20 tons and an intermediate roll bending force of 8 tons. The substrate is smoothed under a smoothing force of 160 tons and an elongation of 0.16%. A quarter-wave plate is used to control the plate shape on both sides of the substrate to obtain a high-strength aluminum-zinc plate with a thickness of 0.97 mm.

[0022] Embodiment 6: This embodiment provides a high-strength galvanized sheet produced by a modified Sendzimir process, including pickling, cold rolling, hot-dip galvanizing, high-temperature annealing, rapid cold rolling and skin pass; The specific steps include: 1) The substrate was pickled at a concentration of 22% hydrochloric acid, a pickling temperature of 84°C and a pickling speed of 175 m / min; The substrate is made of 25MnTiB hot-rolled coil with a Mn content of ≥1.2% and a Cr content of ≥0.15%; 2) When the roll diameter is 410 mm, the concentration of rolling oil is 4%, and the post tension is 130 N / mm 2 The pickled substrate is cold rolled under the condition of 3) The cold-rolled substrate is passed through an aluminum-zinc liquid at 560°C to plate the metal aluminum-zinc on the surface of the substrate; 4) The aluminum-zinc plated substrate was annealed at 878°C. After annealing, the temperature of the first and second zones of the cooling section was controlled to drop to 600°C. The substrate was rolled under a working roll bending force of 20 tons and an intermediate roll bending force of 8 tons. The substrate was smoothed under a smoothing force of 180 tons and an elongation of 0.2%. A quarter-wave plate was used to control the plate shape on both sides of the substrate to obtain a high-strength aluminum-zinc plate with a thickness of 1.1 mm.

[0023] Embodiment 7: This embodiment provides a high-strength galvanized sheet produced by a modified Sendzimir process, including pickling, cold rolling, hot-dip galvanizing, high-temperature annealing, rapid cold rolling and skin pass; The specific steps include: 1) Pickling the substrate at a concentration of 20% hydrochloric acid, a pickling temperature of 82°C and a pickling speed of 160m / min; The substrate is made of 25MnTiB hot-rolled coil with a Mn content of ≥1.2% and a Cr content of ≥0.15%; 2) When the roller diameter is 410mm, the concentration of rolling oil is ≥4%, and the post tension is 120N / mm 2 The pickled substrate is cold rolled under the condition of 3) The cold-rolled substrate is passed through an aluminum-zinc liquid at 550°C to plate the metal aluminum-zinc on the surface of the substrate; 4) The aluminum-zinc plated substrate is annealed at 880°C. After annealing, the temperature of the first and second zones of the cooling section is controlled to drop to 600°C. The substrate is rolled under a working roll bending force of 20 tons and an intermediate roll bending force of 8 tons. The substrate is smoothed under a smoothing force of 170 tons and an elongation of 0.25%. A quarter-wave plate is used on both sides of the substrate to control the plate shape, thereby obtaining a high-strength aluminum-zinc plate with a thickness of 0.98 mm.

[0024] Comparative Example 1: Select the existing commercially available JIS G3302 SGCH steel strip.

[0025] Experimental Example: The high-strength galvanized aluminum sheets of Examples 1 to 7 and Comparative Example 1 were subjected to a tensile strength test (GB / T32498-2016 Metal Matrix Composite Material Tensile Test Room Temperature Test Method), and the results are as follows (unit: MPa): project Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 Embodiment 5 Embodiment 6 Embodiment 7 Comparative Example 1 tensile strength ≥709 ≥725 ≥729 ≥733 ≥708 ≥717 ≥715 650 The present invention takes high temperature, high concentration and high pickling speed as the key points of process control in the pickling production process, ensures good pickling effect through high pickling temperature and pickling concentration, and at the same time ensures that the corrosion of the steel coil surface by pickling is minimized; in the cold rolling production, the stability of the plate shape and thickness is ensured by the process measures of reducing the rolling force; in the production of galvanized steel, a high-strength annealing process is realized by high-temperature annealing, and galvanized steel is produced in a manner of high smoothing force and high elongation to ensure high yield strength.

[0026] The present invention accurately plans a set of process standards in the integrated production process system of pickling, cold rolling and galvanizing, which accurately meets the production requirements of high-strength galvanized sheet materials. Through sophisticated process control means, the high stability and quality consistency of galvanized sheet materials are ensured (tensile strength is always stable at more than 700Mpa). This production process not only successfully realizes the stable operation of the process, but also shows the advantages of concise and clear process flow, convenient and efficient production control, and its low cost control makes it the preferred solution for the production of 0.95mm thick high-strength galvanized sheet materials.

[0027] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will 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 process for producing high-strength galvanized steel sheet using a modified Sendzimir process, characterized in that: Including pickling, cold rolling, hot-dip galvanizing, high temperature annealing, rapid cold rolling and skin pass; The specific steps include: 1) Pickling the substrate at a concentration of 15-25% hydrochloric acid, a pickling temperature of 70-90°C and a pickling speed of 130-180m / min; 2) When the roller diameter is 400-430mm, the concentration of rolling oil is ≥4%, and the post tension is 80-160N / mm 2 The pickled substrate is cold rolled under the condition of 3) The cold-rolled substrate is passed through an aluminum-zinc liquid at 500-600°C to plate the metal aluminum-zinc on the surface of the substrate; 4) The aluminum-zinc plated substrate is annealed at ≥870°C, and after annealing, the temperature of the first zone and the second zone of the cooling section is controlled to be reduced to ≤600°C for rolling, and is subjected to skin finishing under the conditions of skin finishing force ≥150 tons and elongation ≥0.15%, thereby obtaining a high-strength aluminum-zinc plate.

2. The process for producing high-strength galvanized steel sheet by using the modified Sendzimir process according to claim 1, characterized in that: Step 1) is specifically: pickling the substrate at a concentration of 18-20% hydrochloric acid, a pickling temperature of 80-82° C., and a pickling speed of 150-160 m / min.

3. The process for producing high-strength galvanized steel sheet by using the modified Sendzimir process according to claim 2, characterized in that: Step 2) is as follows: when the roller diameter is 400-420mm, the concentration of rolling oil is ≥4%, and the post tension is 100-120N / mm 2 The pickled substrate is cold rolled under the conditions of.

4. The process for producing high-strength galvanized steel sheet by using the modified Sendzimir process according to claim 3, characterized in that: Step 3) is specifically as follows: the cold-rolled substrate is passed through an aluminum-zinc liquid at 530-560° C. to plate metal aluminum-zinc on the surface of the substrate.

5. The process for producing high-strength galvanized steel sheet by using the modified Sendzimir process according to claim 4, characterized in that: In the step 4), after annealing, the temperature of the first zone and the second zone of the cooling section is controlled to be lowered to ≤ 600° C., and rolling is performed under the action of a working roll bending force of more than 20 tons and an intermediate roll bending force of more than 8 tons.

6. The process for producing high-strength galvanized steel sheet by using the modified Sendzimir process according to claim 5, characterized in that: The substrate is made of 25MnTiB hot-rolled coil with a Mn content of ≥1.2% and a Cr content of ≥0.15%.

7. The process for producing high-strength galvanized steel sheet by using the modified Sendzimir process according to claim 6, characterized in that: The thickness of the high-strength galvanized aluminum sheet is ≥0.95 mm.

8. A high-strength galvanized steel sheet produced by the process for producing high-strength galvanized steel sheet by the improved Sendzimir process as described in any one of claims 1 to 7.