Medium-strength high-conductivity Al-Mg-Si alloy plate for power transmission and preparation method thereof

Abstract

The invention discloses a moderate-strength high-conductivity Al-Mg-Si alloy plate for power transmission and a preparation method of the moderate-strength high-conductivity Al-Mg-Si alloy plate, and relates to the field of moderate-strength high-conductivity Al-Mg-Si alloy plates for power transmission. The invention aims to solve the technical problem that the current aluminum alloy for power transmission is large in dead weight. The method comprises the following steps: hot rolling after homogenizing heat treatment; slicing to obtain a hot-rolled plate; carrying out solid solution quenching treatment; stretching is conducted; and aging treatment. According to the medium-strength and high-conductivity Al-Mg-Si alloy plate and the preparation method thereof, by controlling the thermal deformation temperature, the deformation speed and the pass deformation processing rate and cooperating with a proper heat treatment process, more stable subcrystal structures are formed, and therefore the medium-strength and high-conductivity Al-Mg-Si alloy plate with the strength and the conductivity well matched is obtained. The Al-Mg-Si alloy plate prepared by the preparation method disclosed by the invention is used for power transmission.

Description

Technical Field

[0001] This invention relates to the field of medium-strength, high-conductivity Al-Mg-Si alloy plates for power transmission. Background Technology

[0002] Aluminum alloys, with their lightweight, high specific strength, low cost, ease of processing, corrosion resistance, and high electrical conductivity, have long been a key structural material for high-voltage engineering projects, smart grids, intercity railways, and urban subways. In the contemporary fields of power transmission and rail transit, aluminum alloys have consistently been one of the most important materials used in power system construction structures, accounting for approximately 70% to 80% of the structural weight. They are widely used in high-voltage transmission and transformation busbars, conductor bars, and conductive structural components in subways and high-speed railways. With the rapid development of the power industry, there is an urgent need to develop aluminum alloys with superior overall performance to replace existing alloys and meet the material requirements for upgrading next-generation power equipment. Summary of the Invention

[0003] This invention addresses the technical problem of the excessive weight of aluminum alloys currently used for power transmission by providing a hot deformation and heat treatment process for a medium-strength, high-conductivity Al-Mg-Si alloy sheet for power transmission.

[0004] A medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission, wherein the percentage content of each element in the plate is as follows: Mg 0.35%~0.80%, Si 0.30%~0.70%, Fe ≤0.50%, Cu ≤0.10%, B ≤0.06%, Zn ≤0.10%, the content of a single impurity does not exceed 0.03%, and the balance is Al.

[0005] Furthermore, the percentage content of each element in the board is as follows: Mg 0.50%, Si 0.43%, Fe 0.11%, Cu 0.004%, B 0.001%, Zn 0.01%, the content of a single impurity does not exceed 0.03%, and the balance is Al.

[0006] A method for preparing a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission, comprising the following steps:

[0007] 1. The ingot is subjected to homogenization heat treatment at a temperature of 440~460℃ for 16 hours. Then, the ingot is held at 450℃ for 10 hours and then hot rolled at a temperature of 440~460℃. After exiting the furnace, it is subjected to multiple hot rough rolling passes at a rolling speed of 1.50~3.00m / s until the finished thickness is reached. Then, it is air-cooled to room temperature to obtain a hot-rolled plate.

[0008] 2. Slice the hot-rolled plate prepared in step 1 to obtain hot-rolled sheet;

[0009] 3. The hot-rolled sheet obtained in step 2 is subjected to solution quenching treatment at a temperature of 540℃ and a total solution heating and holding time of 40~50min.

[0010] IV. The plate after solution quenching in step three is stretched.

[0011] 5. The plate obtained in step 4 is subjected to aging treatment at an aging temperature of 205~220℃ for 10 hours to obtain a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission, thus completing the process.

[0012] Furthermore, the percentage content of each element in the ingot mentioned in step one is as follows: Mg 0.35%~0.80%, Si 0.30%~0.70%, Fe ≤0.50%, Cu ≤0.10%, B ≤0.06%, Zn ≤0.10%, the content of a single impurity does not exceed 0.03%, and the balance is Al.

[0013] Furthermore, the processing rate per pass in the first hot rolling process is ≤30%.

[0014] Furthermore, the processing rate per pass in the first hot rolling process is ≤20%.

[0015] Furthermore, the hot rolling heating temperature in step one is 450°C.

[0016] Furthermore, step two involves slicing the hot-rolled sheet to obtain a length of 10,000 mm to 20,000 mm.

[0017] Furthermore, in step four, the stretching amount is controlled to be ≤1.5%.

[0018] Furthermore, the sheet material obtained in step four has a tensile strength higher than 190 MPa, a yield strength higher than 160 MPa, an elongation higher than 16%, and an electrical conductivity higher than 56.2% IACS.

[0019] This invention provides a medium-strength, high-conductivity Al-Mg-Si alloy sheet suitable for power transmission, achieving an upgrade of aluminum alloy sheets for power transmission. The obtained medium-strength, high-conductivity Al-Mg-Si alloy sheet has good tensile strength, yield strength, elongation, and electrical conductivity.

[0020] This invention provides a medium-strength, high-conductivity Al-Mg-Si alloy sheet for power transmission, which has significant application value in electrical fields such as high and low voltage electrical appliances, switchgear, transformers, as well as in rail transit vehicle body structures and automotive radiator structures. It can replace 7xxx series alloys such as 7075 and 7021 in situ, achieving a weight reduction of 5% to 8%. Further leveraging its advantages, by fully utilizing its weldability, bendability, and stamping characteristics, combined with welding and forming processes, a structural weight reduction of 10% to 15% can be achieved.

[0021] Beneficial effects of this invention:

[0022] This invention discloses a hot deformation and heat treatment process for a medium-strength, high-conductivity Al-Mg-Si alloy for power transmission. By employing Fe and Si microalloying elements for composite microalloying and controlling the formation of fine and dispersed Mg2Si second phase in the microstructure through homogenization heat treatment, the strength and recrystallization completion temperature of the alloy are improved. By controlling the hot deformation temperature, deformation speed, and per-pass deformation rate, and in conjunction with an appropriate heat treatment process, a large number of stable subgrain structures are formed, thereby obtaining a medium-strength, high-conductivity Al-Mg-Si alloy sheet with a good match between strength and electrical conductivity.

[0023] The Al-Mg-Si alloy sheet prepared by this invention is used for power transmission. Attached Figure Description

[0024] Figure 1 The image shows a physical sample of the medium-strength, high-conductivity Al-Mg-Si alloy plate prepared in Example 1.

[0025] Figure 2 This is a photograph of the medium-strength, high-conductivity Al-Mg-Si alloy plate prepared in Example 2. Detailed Implementation

[0026] Specific Implementation Method 1: This implementation method provides a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission. The percentage content of each element in the plate is as follows: Mg 0.35%~0.80%, Si 0.30%~0.70%, Fe ≤0.50%, Cu ≤0.10%, B ≤0.06%, Zn ≤0.10%, and the content of a single impurity does not exceed 0.03%, with the balance being Al.

[0027] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the percentage content of each element in the board is as follows: Mg 0.50%, Si 0.43%, Fe 0.11%, Cu 0.004%, B 0.001%, Zn 0.01%, and the content of a single impurity does not exceed 0.03%, with the balance being Al. Everything else is the same as in Specific Implementation Method One.

[0028] Specific Implementation Method 3: This implementation method provides a method for preparing a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission. The method is carried out according to the following steps:

[0029] 1. The ingot is subjected to homogenization heat treatment at a temperature of 440~460℃ for 16 hours. Then, the ingot is held at 450℃ for 10 hours and then hot rolled at a temperature of 440~460℃. After exiting the furnace, it is subjected to multiple hot rough rolling passes at a rolling speed of 1.50~3.00m / s until the finished thickness is reached. Then, it is air-cooled to room temperature to obtain a hot-rolled plate.

[0030] 2. Slice the hot-rolled plate prepared in step 1 to obtain hot-rolled sheet;

[0031] 3. The hot-rolled sheet obtained in step 2 is subjected to solution quenching treatment at a temperature of 540℃ and a total solution heating and holding time of 40~50min.

[0032] IV. The plate after solution quenching in step three is stretched.

[0033] 5. The plate obtained in step 4 is subjected to aging treatment at an aging temperature of 205~220℃ for 10 hours to obtain a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission, thus completing the process.

[0034] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method Three in that the percentage content of each element in the ingot described in Step One is as follows: Mg 0.35%~0.80%, Si 0.30%~0.70%, Fe ≤0.50%, Cu ≤0.10%, B ≤0.06%, Zn ≤0.10%, and the content of a single impurity does not exceed 0.03%, with the balance being Al. Everything else is the same as in Specific Implementation Method Three.

[0035] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods Three or Four in that the processing rate per pass in the hot rolling process of Step One is ≤30%. Everything else is the same as in Specific Implementation Methods Three or Four.

[0036] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods Three to Five in that the processing rate per pass in the hot rolling process of Step One is ≤20%. Everything else is the same as in Specific Implementation Methods Three to Five.

[0037] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods Three to Six in that the hot rolling heating temperature in step one is 450℃. Everything else is the same as in Specific Implementation Methods Three to Six.

[0038] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods Three to Seven in that the length of the hot-rolled sheet obtained in step two is 10000mm~20000mm. Everything else is the same as in Specific Implementation Methods Three to Seven.

[0039] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods Three to Eight in that step four controls the stretching amount to be ≤1.5%. Everything else is the same as in Specific Implementation Methods Three to Eight.

[0040] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods Three to Nine in that the tensile strength of the sheet material obtained in step four is higher than 190 MPa, the yield strength is higher than 160 MPa, the elongation is higher than 16%, and the electrical conductivity is higher than 56.2% IACS. Everything else is the same as in Specific Implementation Methods Three to Nine.

[0041] The scope of this invention is not limited to the above-described embodiments; a combination of one or more specific embodiments can also achieve the purpose of the invention.

[0042] Example 1:

[0043] This embodiment describes a method for preparing a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission. The method comprises the following steps:

[0044] 1. The ingot is subjected to homogenization heat treatment. The percentage content of each element in the ingot is as follows: Mg 0.50%, Si 0.43%, Fe 0.11%, Cu 0.004%, B 0.001%, Zn 0.01%, and the content of a single impurity does not exceed 0.03%, with the balance being Al. The heat treatment temperature is 450±10℃ and the heat treatment time is 16h. Then, the ingot is held at 450℃ for 10h and then hot rolled. The hot rolling heating temperature is 450℃. After exiting the furnace, it is subjected to multiple hot rough rolling passes, with the rolling speed controlled at 1.50~3.00m / s and the processing rate of each pass ≤20%, rolled to a thickness of 25mm. Then, it is air-cooled to room temperature to obtain a hot-rolled plate.

[0045] 2. Cut the hot-rolled plate prepared in step 1 into slices to obtain hot-rolled sheet pieces, each of which has a length of 10000mm~20000mm;

[0046] 3. The hot-rolled sheet obtained in step 2 is subjected to solution quenching treatment at a solution temperature of 540℃ and a total solution heating and holding time of 50min.

[0047] 4. The plate after solution quenching in step 3 is subjected to tensile treatment, with a tensile amount of ≤1.5%;

[0048] 5. The plate obtained in step 4 is subjected to aging treatment at an aging temperature of 205℃ for 10 hours to obtain a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission, thus completing the process.

[0049] The sheet material obtained in Example 1 was subjected to tensile property testing, and the tensile properties are shown in Table 1.

[0050] Comparative Example 1:

[0051] 1. The ingot is subjected to homogenization heat treatment. The percentage content of each element in the ingot is as follows: Mg 0.50%, Si 0.43%, Fe 0.11%, Cu 0.004%, B 0.001%, Zn 0.01%, and the content of a single impurity does not exceed 0.03%, with the balance being Al. The heat treatment temperature is 450±10℃ and the heat treatment time is 16h. Then, the ingot is held at 450℃ for 10h and then hot rolled. The hot rolling heating temperature is 450℃. After exiting the furnace, it is subjected to multiple hot rough rolling passes, with the rolling speed controlled at 1.50~3.00m / s and the processing rate of each pass ≤20%, rolled to a thickness of 25mm. Then, it is air-cooled to room temperature to obtain a hot-rolled plate.

[0052] 2. Cut the hot-rolled plate prepared in step 1 into slices to obtain hot-rolled sheet pieces, each of which has a length of 10000mm~20000mm;

[0053] 3. The hot-rolled sheet obtained in step 2 is subjected to solution quenching treatment at a solution temperature of 540℃ and a total solution heating and holding time of 50min.

[0054] Fourth, the plate after solution quenching in step three is subjected to tensile treatment, with a tensile amount of ≤1.5%.

[0055] The tensile properties of the sheet obtained in Comparative Example 1 are shown in Table 2.

[0056] Example 2:

[0057] This embodiment describes a method for preparing a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission. The method comprises the following steps:

[0058] 1. The ingot is subjected to homogenization heat treatment. The percentage content of each element in the ingot is as follows: Mg 0.50%, Si 0.43%, Fe 0.11%, Cu 0.004%, B 0.001%, Zn 0.01%, and the content of a single impurity does not exceed 0.03%, with the balance being Al. The heat treatment temperature is 450±10℃ and the heat treatment time is 16h. Then, the ingot is held at 450℃ for 10h and then hot rolled. The hot rolling heating temperature is 450℃. After exiting the furnace, it is subjected to multiple passes of hot rough rolling, with the rolling speed controlled at 1.50~3.00m / s and the processing rate of each pass ≤30%, rolled to a thickness of 25mm. Then, it is air-cooled to room temperature to obtain a hot-rolled plate.

[0059] 2. Cut the hot-rolled plate prepared in step 1 into slices to obtain hot-rolled sheet pieces, each of which has a length of 10000mm~20000mm;

[0060] 3. The hot-rolled sheet obtained in step 2 is subjected to solution quenching treatment at a temperature of 540℃ and a total solution heating and holding time of 40min.

[0061] 4. The plate after solution quenching in step 3 is subjected to tensile treatment, with a tensile amount of ≤1.5%;

[0062] 5. The plate obtained in step 4 is subjected to aging treatment at an aging temperature of 205℃ for 10 hours to obtain a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission, thus completing the process.

[0063] The sheet material obtained in Example 2 was subjected to tensile property testing, and the tensile properties are shown in Table 1.

[0064] Comparative Example 2:

[0065] 1. The ingot is subjected to homogenization heat treatment. The percentage content of each element in the ingot is as follows: Mg 0.50%, Si 0.43%, Fe 0.11%, Cu 0.004%, B 0.001%, Zn 0.01%, and the content of a single impurity does not exceed 0.03%, with the balance being Al. The heat treatment temperature is 450±10℃ and the heat treatment time is 16h. Then, the ingot is held at 450℃ for 10h and then hot rolled. The hot rolling heating temperature is 450℃. After exiting the furnace, it is subjected to multiple passes of hot rough rolling, with the rolling speed controlled at 1.50~3.00m / s and the processing rate of each pass ≤30%, rolled to a thickness of 25mm. Then, it is air-cooled to room temperature to obtain a hot-rolled plate.

[0066] 2. Cut the hot-rolled plate prepared in step 1 into slices to obtain hot-rolled sheet pieces, each of which has a length of 10000mm~20000mm;

[0067] 3. The hot-rolled sheet obtained in step 2 is subjected to solution quenching treatment at a temperature of 540℃ and a total solution heating and holding time of 40min.

[0068] Fourth, the plate after solution quenching in step three is subjected to tensile treatment, with a tensile amount of ≤1.5%.

[0069] The tensile properties of the sheet obtained in Comparative Example 2 are shown in Table 2.

[0070] Example 3:

[0071] This embodiment describes a method for preparing a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission. The method comprises the following steps:

[0072] 1. The ingot is subjected to homogenization heat treatment. The percentage content of each element in the ingot is as follows: Mg 0.50%, Si 0.43%, Fe 0.11%, Cu 0.004%, B 0.001%, Zn 0.01%, and the content of a single impurity does not exceed 0.03%, with the balance being Al. The heat treatment temperature is 450±10℃ and the heat treatment time is 16h. Then, the ingot is held at 450℃ for 10h and then hot rolled. The hot rolling heating temperature is 450℃. After exiting the furnace, it is subjected to multiple hot rough rolling passes, with the rolling speed controlled at 1.50~3.00m / s and the processing rate of each pass ≤20%, rolled to a thickness of 25mm. Then, it is air-cooled to room temperature to obtain a hot-rolled plate.

[0073] 2. Cut the hot-rolled plate prepared in step 1 into slices to obtain hot-rolled sheet pieces, each of which has a length of 10000mm~20000mm;

[0074] 3. The hot-rolled sheet obtained in step 2 is subjected to solution quenching treatment at a solution temperature of 540℃ and a total solution heating and holding time of 50min.

[0075] 4. The plate after solution quenching in step 3 is subjected to tensile treatment, with a tensile amount of ≤1.5%;

[0076] 5. The plate obtained in step 4 is subjected to aging treatment at a temperature of 220℃ for 10 hours to obtain a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission.

[0077] The sheet material obtained in Example 3 was subjected to tensile property testing, and the tensile properties are shown in Table 1.

[0078] Comparative Example 3:

[0079] 1. The ingot is subjected to homogenization heat treatment. The percentage content of each element in the ingot is as follows: Mg 0.50%, Si 0.43%, Fe 0.11%, Cu 0.004%, B 0.001%, Zn 0.01%, and the content of a single impurity does not exceed 0.03%, with the balance being Al. The heat treatment temperature is 450±10℃ and the heat treatment time is 16h. Then, the ingot is held at 450℃ for 10h and then hot rolled. The hot rolling heating temperature is 450℃. After exiting the furnace, it is subjected to multiple passes of hot rough rolling, with the rolling speed controlled at 1.50~3.00m / s and the processing rate of each pass ≤30%, rolled to a thickness of 25mm. Then, it is air-cooled to room temperature to obtain a hot-rolled plate.

[0080] 2. Cut the hot-rolled plate prepared in step 1 into slices to obtain hot-rolled sheet pieces, each of which has a length of 10000mm~20000mm;

[0081] 3. The hot-rolled sheet obtained in step 2 is subjected to solution quenching treatment at a temperature of 540℃ and a total solution heating and holding time of 40min.

[0082] Fourth, the plate after solution quenching in step three is subjected to tensile treatment, with a tensile amount of ≤1.5%.

[0083] 5. The tensile sheet obtained in step 4 is subjected to aging treatment at a temperature of 220℃ for 10 hours.

[0084] The tensile properties of the sheet obtained in Comparative Example 2 are shown in Table 2.

[0085] Table 1

[0086]

[0087] Table 2

[0088]

[0089] As shown in Tables 1 and 2, with the increase of the hot rough rolling processing rate in step 1), the solution treatment holding time decreases, resulting in a slight decrease in the yield strength and tensile strength of the alloy, while the elongation increases slightly. With the increase of the aging temperature of the plate, the yield strength and tensile strength of the alloy increase, while the elongation decreases slightly, with no significant overall change. A good balance of strength and electrical conductivity can be obtained by aging at 205℃ and 220℃ for 10 hours.

Claims

1. A medium-strength, high-conductivity Al-Mg-Si alloy sheet for power transmission, characterized in that... The percentage content of each element in the board is as follows: Mg 0.35%~0.80%, Si 0.30%~0.70%, Fe ≤0.50%, Cu ≤0.10%, B ≤0.06%, Zn ≤0.10%, the content of a single impurity does not exceed 0.03%, and the balance is Al.

2. The medium-strength, high-conductivity Al-Mg-Si alloy sheet for power transmission according to claim 1, characterized in that... The percentage content of each element in the board is as follows: Mg 0.50%, Si 0.43%, Fe 0.11%, Cu 0.004%, B 0.001%, Zn 0.01%, with no single impurity content exceeding 0.03%, and the balance being Al.

3. The method for preparing a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission as described in claim 1, characterized in that... This method is performed in the following steps:

1. The ingot is subjected to homogenization heat treatment at a temperature of 440~460℃ for 16 hours. Then, the ingot is held at 450℃ for 10 hours and then hot rolled at a temperature of 440~460℃. After exiting the furnace, it is subjected to multiple hot rough rolling passes at a rolling speed of 1.50~3.00m / s until the finished thickness is reached. Then, it is air-cooled to room temperature to obtain a hot-rolled plate.

2. Slice the hot-rolled plate prepared in step 1 to obtain hot-rolled sheet; 3. The hot-rolled sheet obtained in step 2 is subjected to solution quenching treatment at a temperature of 540℃ and a total solution heating and holding time of 40~50min. IV. The plate after solution quenching in step three is stretched.

5. The plate obtained in step 4 is subjected to aging treatment at an aging temperature of 205~220℃ for 10 hours to obtain a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission, thus completing the process.

4. The method for preparing a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission according to claim 3, characterized in that... The percentage content of each element in the ingot mentioned in step one is as follows: Mg 0.35%~0.80%, Si 0.30%~0.70%, Fe ≤0.50%, Cu ≤0.10%, B ≤0.06%, Zn ≤0.10%, the content of a single impurity does not exceed 0.03%, and the balance is Al.

5. The method for preparing a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission according to claim 3, characterized in that... In Step 1, the processing rate per pass of the hot rolling process is ≤30%.

6. The method for preparing a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission according to claim 3, characterized in that... In Step 1, the processing rate per pass of the hot rolling process is ≤20%.

7. The method for preparing a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission according to claim 3, characterized in that... The hot rolling heating temperature in step one is 450℃.

8. The method for preparing a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission according to claim 3, characterized in that... Step two involves slicing the hot-rolled sheet to obtain a length of 10,000 mm to 20,000 mm.

9. The method for preparing a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission according to claim 3, characterized in that... Step 4: Control the stretching amount to ≤1.5%.

10. The method for preparing a medium-strength, high-conductivity Al-Mg-Si alloy plate for power transmission according to claim 3, characterized in that... The sheet material obtained in step four has a tensile strength higher than 190 MPa, a yield strength higher than 160 MPa, an elongation higher than 16%, and an electrical conductivity higher than 56.2% IACS.

Images