A method for producing iron-chromium-aluminum foil

Abstract

The application provides a method for preparing iron-chromium-aluminum foil, comprising the following steps: performing acid pickling, descaling and softening heat treatment on an iron-chromium-aluminum base material to obtain a to-be-rolled iron-chromium-aluminum coil; performing homogenization heat treatment on the to-be-rolled iron-chromium-aluminum coil to obtain a semi-finished iron-chromium-aluminum coil through primary rolling; and performing cold finish rolling and stress relief annealing on the semi-finished iron-chromium-aluminum coil to obtain a finished iron-chromium-aluminum foil, wherein the parameters of the second intermediate roller and the first intermediate double-cone roller in the primary rolling and the cold finish rolling are specially configured. The method can perform softening heat treatment on a base material with a thickness of 1.0 mm and a width of more than 600 mm, solves the technical bottleneck of compatibility between the thickness and the width of the iron-chromium-aluminum foil, and the prepared foil has high size precision and excellent and stable microstructure and performance, and the production efficiency is improved and the method is green and low-carbon.

Description

Technical Field

[0001] The invention belongs to the field of metal materials and relates to a method for preparing iron-chromium-aluminum foil. Background Art

[0002] Iron-chromium-aluminum foil is a special alloy material with exceptional properties, including high-temperature resistance, oxidation resistance, corrosion resistance, high strength, good ductility, a low coefficient of thermal expansion, and excellent electrical and thermal conductivity. It remains stable at temperatures exceeding 1200°C and is not susceptible to deformation or damage. The stable oxide film formed on its surface effectively prevents further oxidation, significantly extending the material's service life in high-temperature environments. The low coefficient of thermal expansion ensures dimensional stability at high temperatures, making it suitable for precision instruments and equipment.

[0003] With the rapid development and widespread adoption of iron-chromium-aluminum foil in my country's aerospace, new energy, automotive, and electronics industries, there is an urgent need for domestically produced, high-quality, ultra-thin, wide-width iron-chromium-aluminum foil products with thicknesses of 0.02-0.06mm and widths exceeding 600mm. For example, in the aerospace sector, its high-temperature and corrosion-resistant properties are used in the manufacture of aircraft engine components, combustion chamber liners, and thermal protection systems, ensuring aircraft reliability and safety. Industrial heating equipment, such as heating elements and resistor materials in industrial furnaces, benefit from the high-temperature tolerance of iron-chromium-aluminum foil, reducing maintenance frequency and improving equipment efficiency. In automotive exhaust treatment, its use as a catalytic converter substrate not only offers high-temperature and corrosion resistance, but also improves exhaust treatment efficiency and vehicle lifespan. Heating elements in household appliances, such as rice cookers and electric kettles, benefit from the excellent thermal conductivity and high-temperature resistance of iron-chromium-aluminum foil, enhancing their efficiency and durability. In the electronics industry, iron-chromium-aluminum foil, used as heat sinks and heat shielding materials, significantly enhances the performance and reliability of electronic products due to its low thermal expansion coefficient and excellent thermal conductivity.

[0004] Cold rolling is a key core technology for producing ultra-thin and wide-width iron-chromium-aluminum foil. However, during the rolling process, problems such as work hardening, thickness and tolerance accuracy, surface defects, and uneven distribution of microstructure and stress are encountered. In addition, conventional rolling leads to excessive processing passes and intermediate annealing times, increasing production costs and reducing production efficiency. How to effectively solve the plate shape consistency and thickness uniformity of ultra-thin and wide-width foils and break through the technical bottleneck of compatibility between the thinness and width of iron-chromium-aluminum foils,

[0005] In summary, there is a gap in the current research on technical and process methods for preparing ultra-thin and wide-width electric heating alloy iron-chromium-aluminum foil, and the preparation of ultra-thin and wide-width iron-chromium-aluminum foil is limited by both process equipment and technical processes, and the width and thinness are difficult to be compatible. Summary of the Invention

[0006] There is a gap in the process research on the preparation technology of ultra-thin and wide-width iron-chromium-aluminum foil. The present invention proposes a new step-deformation integration technology process path, which maintains the step-deformation integration to prepare ultra-thin and wide-width micron-level iron-chromium-aluminum foil.

[0007] The principle of this invention is to subject a 1.0mm-thick substrate to a softening heat treatment, further optimizing the material's structure and properties and reducing performance parameters such as hardness. Leveraging the high rigidity of the 20-roll Sendzimir mill and the material's high resistance to rollable deformation, the invention employs an integrated manufacturing process that maintains step-shaped deformation, rationally designing the rolling schedule and deformation, mitigating the structural damage caused by the rolling process and eliminating the cumbersome, long-sequence manufacturing process. The final foil specification can be produced using only two cold rolling schedules. Furthermore, by studying the coupling relationship between the roll profile and roll system configuration of the first and second intermediate rolls, the curved depth of the upper and lower idler rolls and the taper length and profile of the first intermediate roll are increased and refined, achieving a flexible match between the differentiated and refined roll configurations, the substrate, and the roughness.

[0008] In order to achieve the above objectives, the present invention provides a method for preparing an iron-chromium-aluminum foil, comprising:

[0009] S1: Pickling, descaling and softening heat treatment are performed on the Fe-Cr-Al substrate to obtain the Fe-Cr-Al coil to be rolled;

[0010] S2: performing primary rolling and homogenization heat treatment on the unrolled Fe-Cr-Aluminum coil to obtain a semi-finished Fe-Cr-Aluminum coil;

[0011] S3: The semi-finished Fe-Cr-Aluminum coil is subjected to cold finishing rolling and stress relief annealing to obtain the finished Fe-Cr-Aluminum foil.

[0012] It is characterized by:

[0013] During the initial rolling process, the two intermediate rolls are configured as follows: the upper and lower idler rolls are concave rolls, the curvature depth is 0.1mm, and the lubricant oil temperature is 40-45°C. The configuration of the middle double-tapered roll is: the taper length at both ends is 50-150mm, the height difference between the two sides of the taper length area is 0.07-0.1mm, and the roughness value is greater than 0.4Ra. The thickness of the semi-finished iron-chromium-aluminum strip obtained is less than 0.1mm.

[0014] During cold finishing rolling, the two intermediate rolls are configured as follows: the upper and lower idler rolls are concave rolls, the curved surface depth is 0.05mm, and the lubricant oil temperature is 35-40°C; the configuration of the middle double-tapered roll is: the taper length at both ends is 30-70mm, the height difference on both sides of the taper length area is 0.06-0.1mm, and the roughness value is 0.13-0.3Ra. The finished iron-chromium-aluminum foil obtained has a thickness of less than 0.02mm and a width of more than 600mm.

[0015] It should be noted that the specifications of the Fe-Cr-Aluminum substrate before rolling are set to a thickness greater than 1.0 mm and a width greater than 600 mm. At the same time, the heat treatment process parameters are pre-set before rolling to obtain the technical requirements of the required rolling process conditions.

[0016] According to an embodiment of the present invention, the annealing temperature of the softening heat treatment is 950-1200°C, the heating rate is 10-20°C / s, and the cooling method is furnace cooling, and finally an iron-chromium-aluminum coil with uniform surface and good microstructure and performance is obtained.

[0017] According to an embodiment of the present invention, the total deformation of the initial rolling is 90-95%, the processing rate of the first pass is controlled at 5-8%, the processing rate of each of the remaining passes is controlled at 17-32%, and the processing rate of the last pass is controlled at 4-8%.

[0018] According to the embodiment of the present invention, the unit tension of the rolling entrance and exit of the primary rolling is controlled to be 100.0~510.0N / mm 2 (±30), the total rolling force is 100.0~150.0T, and the rolling speed is 90.0~200.0m / min.

[0019] According to an embodiment of the present invention, the annealing temperature of the homogenization heat treatment is 910-1050° C., and the heating rate is 18-25° C. / s.

[0020] According to an embodiment of the present invention, the total rolling deformation of cold finishing rolling is 70-80%, the first pass processing rate is controlled at 3-5%, the processing rate of each of the remaining passes is controlled at 10-20%, and the final pass processing rate is controlled at 5-7%.

[0021] It should be noted that the cold rolling material uses M2 and M42 high-hardness working rolls, and the air pressure is controlled between 3 and 4KG.

[0022] According to an embodiment of the present invention, the unit tension difference between the rolling entrance and exit of the cold finishing rolling is 200-420N / mm 2 (±30), the total rolling force is 70.0~200.0T, and the rolling speed is 200.0~400.0m / min.

[0023] Effects of the Invention

[0024] 1. The new step-shaped integrated technology process path proposed in the patent of this invention provides better process guidance and technical support for the preparation method of ultra-thin and wide-width iron-chromium-aluminum foil; and, through the preparation process described in the patent of this invention, the plate size accuracy and mechanical properties of the foil are precisely controlled, the lattice arrangement of the material is more orderly, and the tissue distribution is more uniform, so that it can adapt to a variety of high-precision application environments, fundamentally solving the long-span cold rolling process between the substrate plate and the finished foil, and breaking through the preparation problem of plate shape consistency and thickness uniformity of ultra-thin and wide-width iron-chromium-aluminum foil that is compatible with thinness and width.

[0025] 2. The step-deformation integrated preparation process described in the present invention is to achieve a more precise shape and performance integration process by controlling the degree of deformation in different rolling stages; step-deformation can help avoid excessive deformation or damage of the material during the processing process, ensuring the uniformity and consistency of the foil plate shape.

[0026] 3. The present invention prepares the final foil specifications through only two cold rolling procedures, significantly improving the size and shape accuracy, apparent quality and yield rate of ultra-thin wide-width iron-chromium-aluminum foil, and reducing its production cost.

[0027] 4. The present invention improves the uniform deformation of metal flow during rolling by designing the coupling relationship between the roll shape and the roll system configuration, reduces the relative sliding and surface defects between the rolls and the strip, and improves the rolling efficiency and the plate quality of the product. Specific embodiments

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments in 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic flow chart of the method for preparing iron-chromium-aluminum foil of the present invention.

[0030] Example 1

[0031] This embodiment uses an iron-chromium-aluminum substrate with a thickness of 1.0 mm and a width of 700 mm.

[0032] S1: A 20-high Sendzimir mill was used to produce the pre-rolled FeCrAl coil by pickling, descaling, and softening the FeCrAl substrate. The relevant process parameters are as follows.

[0033] S2: performing initial rolling and homogenization heat treatment on the iron-chromium-aluminum coil to be rolled to obtain a semi-finished iron-chromium-aluminum coil. The configuration parameters of the initial rolling are as follows.

[0034]

[0035] The initial rolling procedure is as follows.

[0036]

[0037] S3: The semi-finished iron-chromium-aluminum coil is subjected to cold finishing rolling and stress annealing to obtain a finished iron-chromium-aluminum foil. The configuration parameters of the cold finishing rolling are as follows.

[0038]

[0039]

[0040] The cold finishing rolling procedures are as follows.

[0041]

[0042] The final product of the iron-chromium-aluminum foil has a thickness of 0.015 mm and a width of 650 mm.

[0043] Example 2

[0044] This embodiment uses an iron-chromium-aluminum substrate with a thickness of 1.5 mm and a width of 750 mm.

[0045] S1: A 20-high Sendzimir mill was used to produce the pre-rolled FeCrAl coil by pickling, descaling, and softening the FeCrAl substrate. The relevant process parameters are as follows.

[0046] S2: performing primary rolling and homogenization heat treatment on the iron-chromium-aluminum coil to be rolled to obtain a semi-finished iron-chromium-aluminum coil. The configuration parameters of the primary rolling are as follows.

[0047]

[0048]

[0049] The initial rolling procedure is as follows.

[0050]

[0051] S3: The semi-finished iron-chromium-aluminum coil is subjected to cold finishing rolling and stress annealing to obtain a finished iron-chromium-aluminum foil. The configuration parameters of the cold finishing rolling are as follows.

[0052]

[0053] The cold finishing rolling procedures are as follows.

[0054]

[0055]

[0056] The final product of the iron-chromium-aluminum foil has a thickness of 0.018 mm and a width of 650 mm.

[0057] Example 3

[0058] This embodiment uses an iron-chromium-aluminum substrate with a thickness of 1.8 mm and a width of 750 mm.

[0059] S1: A 20-high Sendzimir mill was used to produce the pre-rolled FeCrAl coil by pickling, dephosphorization, and softening heat treatment of the FeCrAl substrate. The relevant process parameters are as follows.

[0060] S2: performing primary rolling and homogenization heat treatment on the iron-chromium-aluminum coil to be rolled to obtain a semi-finished iron-chromium-aluminum coil. The configuration parameters of the primary rolling are as follows.

[0061]

[0062] The initial rolling procedure is as follows.

[0063]

[0064] S3: The semi-finished iron-chromium-aluminum coil is subjected to cold finishing rolling and stress annealing to obtain a finished iron-chromium-aluminum foil. The configuration parameters of the cold finishing rolling are as follows.

[0065]

[0066] The cold finishing rolling procedures are as follows.

[0067]

[0068] The final product of the iron-chromium-aluminum foil has a thickness of 0.016 mm and a width of 680 mm.

[0069] It should be noted that the above embodiments are only used as technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing an iron-chromium-aluminum foil, comprising: S1: Pickling, descaling and softening heat treatment are performed on the Fe-Cr-Aluminum substrate to obtain the Fe-Cr-Aluminum coil to be rolled; S2: performing primary rolling and homogenization heat treatment on the iron-chromium-aluminum coil to be rolled to obtain a semi-finished iron-chromium-aluminum coil; S3: cold finishing rolling and stress annealing the semi-finished iron-chromium-aluminum coil to obtain a finished iron-chromium-aluminum foil. It is characterized by: During the initial rolling, the configuration of the two intermediate rolls is as follows: the upper and lower idler rolls are concave rolls, the curved surface depth is 0.1 mm, and the lubricant oil temperature is 40-45°C; the configuration of the middle double-tapered roll is as follows: the tapered lengths at both ends are 50-150 mm, the height difference between the two sides of the tapered length area is 0.07-0.1 mm, and the roughness value is greater than 0.4Ra. The thickness of the obtained semi-finished iron-chromium-aluminum strip is less than 0.1 mm. During the cold finishing rolling, the two intermediate rolls are configured as follows: the upper and lower idler rolls are concave rolls, the curved surface depth is 0.05 mm, and the lubricant oil temperature is 35-40°C; the configuration of the intermediate double-tapered roll is as follows: the taper length at both ends is 30-70 mm, the height difference between the two sides of the taper length area is 0.06-0.1 mm, and the roughness value is 0.13-0.3Ra. The finished iron-chromium-aluminum foil obtained has a thickness of less than 0.02 mm and a width of more than 600 mm.

2. The method for preparing the iron-chromium-aluminum foil according to claim 1, characterized in that The annealing temperature of the softening heat treatment is 950-1200° C., the heating rate is 10-20° C. / s, and the cooling method is furnace cooling.

3. The method for preparing the iron-chromium-aluminum foil according to claim 1, characterized in that The total deformation of the initial rolling is 90-95%, the processing rate of the first pass is controlled at 5-8%, the processing rate of each of the remaining passes is controlled at 17-32%, and the processing rate of the last pass is controlled at 4-8%.

4. The method for preparing the iron-chromium-aluminum foil according to claim 1, characterized in that The unit tension of the rolling entrance and exit of the primary rolling is controlled at 100.0~510.0N / mm 2 , the total rolling force is 100.0~150.0T, and the rolling speed is 90.0~200.0m / min.

5. The method for preparing the iron-chromium-aluminum foil according to claim 1, characterized in that The annealing temperature of the homogenization heat treatment is 910-1050° C., and the heating rate is 18-25° C. / s.

6. The method for preparing the iron-chromium-aluminum foil according to claim 1, characterized in that The total rolling deformation of the cold finishing rolling is 70-80%, the first pass processing rate is controlled at 3-5%, the processing rate of each of the remaining passes is controlled at 10-20%, and the final pass processing rate is controlled at 5-7%.

7. The method for preparing the iron-chromium-aluminum foil according to claim 1, characterized in that The unit tension difference between the cold finishing rolling entrance and exit is 200-420N / mm 2 , the total rolling force is 70.0~200.0T, and the rolling speed is 200.0~400.0m / min.

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