High-strength / strong cube texture metal strip and preparation method thereof

Abstract

The invention discloses a high-strength / strong-cubic-texture metal strip and a preparation method thereof, through alloy component design, a proper amount of W, C, Cr, Mo, Cu, V and other elements are added on the basis of Ni alloy, on the premise of improving ferromagnetism, rolling and heat treatment processes are regulated and controlled, heat treatment atmosphere is reasonably matched, and finally the high-strength strip with the strong cubic texture can be obtained.

Description

Technical Field

[0001] The invention relates to the technical field of metal substrate preparation for second-generation high-temperature coated superconducting tapes, and in particular to a high-strength / strong cubic textured metal tape and a preparation method thereof. Background Art

[0002] The second generation of high temperature superconducting materials represented by YBaCuO need to prepare YBaCuO thin films and deposit them on tough metal substrates to obtain long wires / strips. The deposition of superconducting thin films and the application of superconducting tapes require the metal substrate to have high strength and strong cubic texture. Ni-W alloy is a metal substrate material that has been studied more, but it is difficult to obtain strong cubic texture, no ferromagnetism and high strength at the same time. Generally, with the increase of substrate strength, the content of recrystallized cubic texture decreases significantly, and it is difficult to take into account cubic texture, no ferromagnetism and strength at the same time. At present, strong cubic texture, no ferromagnetism and mechanical properties can be achieved simultaneously in layered composite materials, but it is difficult to prepare large-sized and long composite strips. In single-layer metal strips, the methods for regulating cubic texture and mechanical properties are mainly concentrated in Ni-W alloys. The preparation of single-layer strips is easy to achieve industrial production, but the strength and ferromagnetism need to be further improved. Therefore, the development of new alloy components and corresponding preparation technologies is the key to developing high-performance metal substrates for new superconducting tapes. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention provides a high-strength / strong cubic texture metal strip and a preparation method thereof, which can form a strong cubic texture on the metal strip at high temperature and obtain high strength at the same time.

[0004] The invention provides a high-strength / strong cubic texture metal strip, wherein the chemical composition of the metal strip is: 0.02-0.03% C, 6-7% W, 1.2-1.8% Cr, 1.5-2% Mo, 1.5-2% Cu, 2.5-3% V, and the rest is Ni, all in weight percentage.

[0005] The present invention also provides a method for preparing the above-mentioned high-strength / strong cubic texture metal strip, comprising the following steps: Step (1): obtaining the alloy of the above composition by smelting, and forging it into a billet with a thickness of 50 mm to 60 mm, and controlling the final forging temperature to be above 1000° C.; Step (2): hot rolling the billet obtained in step (1), wherein the hot rolling heating temperature is 1100° C., the heat preservation time is 30 minutes to 40 minutes, the hot rolling thickness is 10 mm to 12 mm, and the final rolling temperature is controlled at above 1000° C.; Step (3): grinding the oxide scale on the surface of the hot-rolled plate obtained in step (2) and then cold-rolling it to a thickness of 2 mm to 2.5 mm, followed by heat treatment. The specific process of the heat treatment is: heating to 520° C. and keeping the temperature for 2 hours; Step (4): cold rolling the heat-treated strip obtained in step (3) to 0.5 mm, and then heat treating the strip. The specific process of the heat treatment is: heating to 520° C. and keeping the temperature for 2 hours; Step (5): cold rolling the strip obtained in step (4) to 0.08 mm to 0.09 mm, and then heat treating the strip. The specific process of the heat treatment is to keep the strip at 580°C to 600°C for 30 minutes, then heat it to 900°C for 30 minutes, and finally heat it to 1200°C for 2 hours.

[0006] Furthermore, the specific process of the heat treatment in step (3) and step (4) is: heating to 520° C. and keeping the temperature for 2 hours.

[0007] Furthermore, the atmosphere of the heat treatment in step (5) is: before the temperature is raised to 1100° C., the atmosphere is protected by argon gas with a purity of 99.99-99.999%; after the temperature is raised to 1100° C., the atmosphere is switched to a mixture of ammonia decomposition gas and pure nitrogen, wherein the volume fraction of nitrogen is 10%-15%.

[0008] Beneficial technical effects of the present invention: The present invention can reduce the ferromagnetism of the strip by adding appropriate amounts of Cr, Mo, Cu and V. The additional addition of an appropriate amount of C can form carbides, refine the grain size after ingot casting and hot rolling, and is conducive to subsequent uniform deformation of cold rolling and retention of cubic-oriented grains. The cubic orientation can be fully recovered through multiple intermediate heat treatments, and then retained in the final cold-rolled strip as a seed for recrystallization nucleation. The purpose of the subsequent high-temperature heat treatment in three steps is to allow the cubic-oriented seeds retained by cold rolling to first recover, recrystallize nucleation and grow at low temperatures, and then use the size advantage to swallow non-cubic-oriented grains at high temperatures, thereby obtaining a strong cubic texture. Through the regulation of the heat treatment atmosphere, nitride pinning can be formed to grow grains, and fine grain strengthening can be achieved to obtain high strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The {111} pole figure after cold rolling to 0.5 mm and heat treatment in Example 1; Figure 2 is the {100} pole figure after the final high temperature heat treatment in Example 1; Figure 3 is the {100} pole figure after the final high temperature heat treatment in Example 2; Figure 4 This is the {100} pole figure after the final high temperature heat treatment in Example 3. DETAILED DESCRIPTION

[0010] The present invention is described in detail below in conjunction with Table 1 and specific implementation methods. Example 1

[0011] The alloy ingot was obtained by vacuum induction melting, and the alloy composition was: 0.02%C, 6%W, 1.8%Cr, 2%Mo, 2%Cu, 3%V, and the rest was Ni, all in weight percentage. The smelted alloy was forged into a billet with a thickness of 50mm, and the final forging temperature was controlled at 1020℃, and then hot rolled, the heating temperature was 1100℃, and the temperature was kept for 40 minutes. The hot rolled thickness was 12mm, and the final rolling temperature was controlled at 1030℃; the oxide scale on the surface of the hot rolled plate was polished and then cold rolled to 2.5mm thick, and then heat treated. The specific process was: heating to 520℃ and keeping warm for 2 hours, and the heat treated strip obtained above was cold rolled to 0.5mm, and then heat treated. The specific process was: heating to 520℃ and keeping warm for 2 hours, and the {111} texture of the strip was as follows: Figure 1 As shown, it can be clearly seen that the strip retains part of the cubic texture; the obtained strip is then cold rolled to 0.08 mm, and finally subjected to high-temperature heat treatment. The specific process is to keep the temperature at 600°C for 30 minutes, then heat it to 900°C for 30 minutes, and finally heat it to 1200°C for 2 hours. The heat treatment atmosphere is: before heating to 1100°C, it is protected by argon gas with a purity of 99.99%. After heating to 1100°C, the atmosphere is switched to a mixture of ammonia decomposition gas and pure nitrogen, in which the volume fraction of nitrogen is 15%. Finally, a high-strength / strong cubic texture strip is obtained. The {100} pole figure of the final strip is shown in Figure 2 As shown, the surface has a sharp cubic texture. The tensile strength and cubic texture content are shown in Table 1. Example 2

[0012] The alloy ingot is obtained by vacuum induction melting, and the alloy composition is: 0.03% C, 6% W, 1.2% Cr, 1.5% Mo, 1.5% Cu, 2.5% V, and the rest is Ni, all in weight percentage. The smelted alloy is forged into a billet with a thickness of 60 mm, and the final forging temperature is controlled at 1010°C, and then hot rolled, the heating temperature is 1100°C, and the temperature is kept for 30 minutes. The hot rolling thickness is 10 mm, and the final rolling temperature is controlled at 1020°C; the oxide scale on the surface of the hot-rolled plate is polished and then cold rolled to 2 mm thick, and then heat treated. The specific process is: heating to 520°C and keeping warm for 2 hours, cold rolling the above-obtained heat-treated strip to 0.5 mm, and then heat treated. The specific process is: heating to 520°C and keeping warm for 2 hours; then the obtained The strip was then cold rolled to 0.09 mm and finally subjected to high temperature heat treatment. The specific process was to keep the temperature at 580 °C for 30 minutes, then heat it to 900 °C for 30 minutes, and finally heat it to 1200 °C for 2 hours. The heat treatment atmosphere was: before heating to 1100 °C, it was protected by argon gas with a purity of 99.999%. After heating to 1100 °C, the atmosphere was switched to a mixture of ammonia decomposition gas and pure nitrogen, in which the volume fraction of nitrogen was 10%. Finally, a high-strength / strong cubic texture strip was obtained. The {100} pole figure of the final strip is as follows: Figure 3 As shown, the surface has a sharp cubic texture. The tensile strength and cubic texture content are shown in Table 1. Example 3

[0013] The alloy ingot is obtained by vacuum induction melting, and the alloy composition is: 0.02% C, 7% W, 1.8% Cr, 2% Mo, 2% Cu, 3% V, and the rest is Ni, all in weight percentage. The smelted alloy is forged into a billet with a thickness of 60 mm, and the final forging temperature is controlled at 1030°C, and then hot rolled, the heating temperature is 1100°C, and the temperature is kept for 40 minutes. The hot rolling thickness is 12 mm, and the final rolling temperature is controlled at 1010°C; the oxide scale on the surface of the hot-rolled plate is polished and then cold rolled to 2.5 mm thick, followed by heat treatment. The specific process is: heating to 520°C and keeping warm for 2 hours, cold rolling the above-obtained heat-treated strip to 0.5 mm, and then heat treatment. The specific process is: heating to 520°C and keeping warm for 2 hours; then The obtained strip is then cold rolled to 0.08 mm and finally subjected to high temperature heat treatment. The specific process is to keep the temperature at 580°C for 30 minutes, then heat it to 900°C for 30 minutes, and finally heat it to 1200°C for 2 hours. The heat treatment atmosphere is: before heating to 1100°C, it is protected by argon gas with a purity of 99.99%. After heating to 1100°C, the atmosphere is switched to a mixture of ammonia decomposition gas and pure nitrogen, in which the volume fraction of nitrogen is 10%. Finally, a high-strength / strong cubic texture strip is obtained. The {100} pole figure of the final strip is as follows: Figure 4 As shown, the surface has a sharp cubic texture. The tensile strength and cubic texture content are shown in Table 1.

[0014] Table 1 Tensile strength and cubic texture content of the strips in Examples 1 to 3

Claims

1. A high strength / strong cubic texture metal strip, characterized in that: The chemical composition of the metal strip is: 0.02-0.03% C, 6-7% W, 1.2-1.8% Cr, 1.5-2% Mo, 1.5-2% Cu, 2.5-3% V, and the rest is Ni, all in weight percentage.

2. The method for preparing a high-strength / strong cubic texture metal strip according to claim 1, characterized in that: The following steps are involved: Step (1): obtaining an alloy of the composition described in claim 1 by smelting, and forging it into a billet with a thickness of 50 mm to 60 mm, and controlling the final forging temperature to be above 1000° C.; Step (2): hot rolling the billet obtained in step (1), wherein the hot rolling heating temperature is 1100° C., the heat preservation time is 30 minutes to 40 minutes, the hot rolling thickness is 10 mm to 12 mm, and the final rolling temperature is controlled at above 1000° C.; Step (3): grinding the oxide scale on the surface of the hot-rolled plate obtained in step (2), cold-rolling the plate to a thickness of 2 mm to 2.5 mm, and then heat treating the plate; Step (4): cold rolling the heat-treated strip obtained in step (3) to 0.5 mm, and then heat treating; Step (5): The strip obtained in step (4) is further cold-rolled to 0.08 mm to 0.09 mm, and then heat-treated.

3. The method for preparing a high-strength / strong cubic texture metal strip according to claim 2, characterized in that: The specific process of the heat treatment in step (3) and step (4) is: heating to 520° C. and keeping the temperature for 2 hours.

4. The method for preparing a high-strength / strong cubic texture metal strip according to claim 2, characterized in that: The specific process of the heat treatment in step (5) is to keep the temperature at 580°C-600°C for 30 minutes, then raise the temperature to 900°C for 30 minutes, and finally raise the temperature to 1200°C for 2 hours.

5. The method for preparing a high-strength / strong cubic texture metal strip according to claim 4, characterized in that: The atmosphere of the heat treatment in step (5) is: before the temperature is raised to 1100° C., it is protected by argon gas with a purity of 99.99-99.999%; after the temperature is raised to 1100° C., the atmosphere is switched to a mixture of ammonia decomposition gas and pure nitrogen, wherein the volume fraction of nitrogen is 10-15%.

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