CN102061410B - Al-Mg-Si alloy sheet and manufacturing method thereof - Google Patents

Abstract

An AlMgSi alloy plate and a preparation method thereof, belonging to the field of material technology, the composition contains Mg0.4-0.8%, Si1-1.5%, Cu0.7-0.8%, Mn0.1-0.3%, Er0.1- 0.5%, Zr0.1~0.2%, the balance is Al; the preparation method is: preheat aluminum and put it in a heating furnace to melt; preheat AlEr alloy, AlZr alloy, AlCu alloy, AlSi alloy and AlMn alloy and add Put it into the molten metal aluminum, keep it warm after melting; cool down to 735±5°C, stir, remove slag, and add covering agent; use a bell jar to press metal magnesium into the melt to keep it warm to obtain a molten alloy; Ethyl chloride is pressed into the molten alloy, after the generation of bubbles is stopped, the temperature is lowered and poured, and the alloy billet is obtained after solidification; the alloy billet is heated and kept for heat preservation, then cooled down, hot-rolled and cold-rolled at room temperature, and then kept at 540±5°C for 1~2h, Quenching, then raise the temperature to 180±5°C for 4~5h. The AlMgSi alloy plate of the invention has excellent performance, simple preparation method, improved process effect and reduced production energy consumption.

Description

A kind of AlMgSi alloy plate and preparation method thereof

technical field

The invention belongs to the field of material technology, in particular to an AlMgSi alloy plate and a preparation method thereof.

Background technique

Aluminum-magnesium-silicon alloy is a rapidly developing alloy in the modern automobile industry. At present, it is widely valued by the world's automobile industry. Based on the requirements of energy conservation and environmental protection, aluminum-magnesium-silicon alloy has a wide range of use as a lightweight material for automobiles. Automobile manufacturers and Scientific research institutions are actively developing aluminum alloys for automobile body panels to achieve stable quality, optimize processes, and reduce costs. The AlMgSi series alloy that can be strengthened by heat treatment has medium strength, high plasticity, excellent weldability, good cold workability, good forging performance, no scale on the surface during hot forging, good surface quality after forging, small machining allowance, and material resistance It has good corrosion resistance and no tendency to stress corrosion cracking, so it is very popular among automobile manufacturers in the manufacture of automobile bodies and key stress-bearing parts.

However, the elongation and tensile strength of the current aluminum-magnesium-silicon alloys cannot meet the requirements, and the development of an aluminum-magnesium-silicon alloy with better comprehensive properties is an urgent problem to be solved.

Contents of the invention

Aiming at the performance deficiency of the existing Al-Mg-Si alloy, the present invention provides an AlMgSi alloy plate and its preparation method; by adding trace rare earth elements into the Al-Mg-Si alloy, and a reasonable process, the tensile strength exceeds 400MPa, AlMgSi alloy with an elongation of 17% or more.

The composition of the AlMgSi alloy plate of the present invention contains 0.4-0.8% of Mg, 1-1.5% of Si, 0.7-0.8% of Cu, 0.1-0.3% of Mn, 0.1-0.5% of Er, 0.1-0.2% of Zr, and the balance for Al.

The above-mentioned AlMgSi alloy plate has a tensile strength>400MPa, a yield strength>300MPa, and an elongation>17%.

The above-mentioned AlMgSi alloy plate contains ErMnSi phase.

The preparation method of AlMgSi alloy sheet material of the present invention is carried out according to the following steps:

1. Preheat metal aluminum at 200~250°C for 1~2h, and then melt it in a heating furnace with a temperature of 755±5°C;

2. Preheat AlEr alloy, AlZr alloy, AlCu alloy, AlSi alloy and AlMn alloy at 200~250℃ for 1~2h respectively, and then add them to the molten metal aluminum. After the alloy is completely melted, keep it at 755±5℃ 15~20min;

3. When the temperature of the melt after heat preservation is lowered to 735±5°C, stir the melt evenly, then remove the slag, and then add covering agent. The amount of covering agent added is 2~3% of the total weight of the melt;

4. Press metal magnesium into the melt with a bell jar for 3~5 minutes, take out the bell jar, and keep it warm at 735±5°C for 30~40 minutes to obtain a molten alloy; the amount of various metals and alloys is based on the amount of each element in the molten alloy The weight percentage is Mg 0.4~0.8%, Si 1~1.5%, Cu 0.7~0.8%, Mn 0.1~0.3%, Er 0.1~0.5%, Zr 0.1~0.2%, the balance is Al, and the metal magnesium is added according to the amount Add 80~100% in excess;

5. Use a bell jar to press solid hexachloroethane into the molten alloy to remove impurities. The amount of hexachloroethane is 4-5% of the total weight of the molten alloy. After the molten alloy stops generating bubbles, cool the molten alloy to 680 ~700°C, and then poured into a crucible preheated at 200±5°C for 1~2h to make a billet, and the molten alloy is solidified to obtain an alloy billet;

6. Heat the alloy billet to 520±5°C for 10~15h for homogenization annealing, then cool down to 430±5°C for 1~2h, then carry out three passes of hot rolling at 430±5°C, and then carry out three passes The normal temperature cold rolling of the pass requires a total reduction of 85~90% to obtain rolled plates;

7. Heat the rolled plate at 540±5°C for 1~2h for solid solution, then quench it with room temperature water, then raise the temperature to 180±5°C for 4~5h for aging heat treatment, and obtain the AlMgSi alloy sheet.

Stirring the melt evenly in the above method is to open an opening on the conjunctiva on the surface of the melt, and use a rod-shaped object to stir up and down in the melt to make the melt evenly mixed.

The slag removal in the above method is to preheat the slag removal spoon at 200~250°C for 1~2h, and then use the slag removal spoon to remove the impurities above the melt.

In the above method, using a bell jar to press metal magnesium into the melt is to preheat the bell jar at 200~250°C for 1~2h, then put the metal magnesium into the bell jar, and use the bell jar to press the metal magnesium into the melt middle.

In the above method, the bell jar is used to press the solid hexachloroethane into the molten alloy. Firstly, the bell jar is preheated at 200~250°C for 1~2h, and then the solid hexachloroethane is put into the bell jar, and the bell jar is used to Solid hexachloroethane is pressed into the melt.

The above-mentioned covering agent is a mixed salt of potassium chloride and sodium chloride, wherein the weight percentage of potassium chloride is 50%.

When three passes of hot rolling are carried out in the above method, the reduction in the first pass is controlled at 45-50%. After each pass of hot rolling, the alloy billet is held at 430±5°C for 10-15 minutes for recrystallization annealing. To eliminate deformation resistance.

The composition of the AlMgSi alloy plate of the present invention is mostly conventional metals, the amount of rare earth elements contained is small, and the cost of the alloy is increased less. Through reasonable element composition and preparation process, the comprehensive performance alloy plate product can be obtained, and the preparation process does not need to adopt special Equipment, cold rolling is adopted after hot rolling, which improves the process effect and reduces production energy consumption.

Description of drawings

Fig. 1 is the exterior view of the rolling plate in the embodiment 1 of the present invention;

Fig. 2 is the metallographic structure diagram of the AlMgSi alloy plate in Example 1 of the present invention;

Fig. 3 is an XRD phase diagram of the AlMgSi alloy plate in Example 1 of the present invention.

Detailed ways

The weight purity of metal aluminum adopted in the embodiment of the present invention is more than or equal to 99.99%;

The metal magnesium weight purity that adopts in the embodiment of the present invention is more than or equal to 99.99%;

The AlEr alloy selected in the embodiment of the present invention is a commercially available Al-13Er alloy;

The AlZr alloy selected in the embodiment of the present invention is a commercially available Al-4Zr alloy;

The AlCu alloy selected in the embodiment of the present invention is a commercially available Al-50Cu alloy;

The AlSi alloy selected in the embodiment of the present invention is a commercially available Al-26Si alloy;

The AlMn alloy selected in the embodiment of the present invention is a commercially available Al-10Mn alloy;

The solid-state hexachloroethane that adopts in the embodiment of the present invention is a commercially available product;

Potassium chloride and sodium chloride adopted in the embodiment of the present invention are commercially available products;

The heating furnace that adopts in the embodiment of the present invention is a 30kW well type resistance furnace;

The crucible adopted in the embodiment of the present invention is a graphite crucible;

Stirring the melt evenly in the embodiment of the present invention is to open an opening on the conjunctiva on the surface of the melt, and use a metal rod to stir up and down in the melt to make the melt evenly mixed.

Example 1

Preheat metal aluminum at 200°C for 2 hours, and then melt it in a heating furnace with a temperature of 755±5°C;

Preheat AlEr alloy, AlZr alloy, AlCu alloy, AlSi alloy and AlMn alloy at 200°C for 2 hours respectively, and then add them to the molten metal aluminum. After the alloy is completely melted, keep it at 755±5°C for 15 minutes;

When the temperature of the heat-preserved melt has dropped to 735±5°C, stir the melt evenly, preheat the slag-removing spoon at 200°C for 2 hours, then use the slag-removing spoon to remove the slag, and then add the covering agent, which is potassium chloride Mixed salt with sodium chloride, wherein the percentage by weight of potassium chloride is 50%, and the addition of covering agent is 2% of the total weight of the melt;

Preheat the bell jar at 250°C for 1 hour, then put the metal magnesium into the bell jar, press the metal magnesium into the melt with the bell jar for 3 minutes, take out the bell jar, and keep it at 735±5°C for 40 minutes to obtain a molten alloy The amount of various metals and alloys is Mg 0.8%, Si 1%, Cu 0.8%, Mn 0.2%, Er 0.4%, Zr 0.15% according to the weight percentage of each element in the molten alloy, and the balance is Al, and the metal magnesium Add 100% in excess according to the amount added;

First preheat the bell jar at 250°C for 1 hour, then put solid hexachloroethane into the bell jar, press the solid hexachloroethane into the molten alloy to remove impurities with the bell jar, the amount of hexachloroethane is 5% of the total weight. After the molten alloy stops generating bubbles, the molten alloy is cooled to 700°C, and then poured into a crucible preheated at 200±5°C for 1 hour to make a blank, and the molten alloy is solidified to obtain an alloy blank;

Heat the alloy billet to 520±5°C for 15 hours, then cool it down to 430±5°C and hold it for 1 hour, then carry out three passes of hot rolling at 430±5°C, with the reduction of the first pass controlled at 47%. After each pass of hot rolling, the alloy billet is held at 430±5°C for 15 minutes for recrystallization annealing, and then three passes of normal temperature cold rolling are carried out after hot rolling. The total reduction of hot rolling and cold rolling is required to be 86%. , to obtain rolled plate;

The rolled plate is kept at 540±5°C for 2 hours for solid solution, then quenched with room temperature water, and then heated to 180±5°C for 5 hours to obtain an AlMgSi alloy plate, the composition of which contains Mg 0.8%, Si 1%, Cu 0.8%, Mn 0.2%, Er 0.4%, Zr 0.15%, and the balance is Al; the tensile strength is 437.7MPa, the yield strength is 352.8MPa, and the elongation is 19%; the AlMgSi alloy plate contains ErMnSi phase; the appearance is shown in Figure 1 The metallographic structure is shown in Figure 2, and the XRD is shown in Figure 3.

Example 2

Preheat metal aluminum at 220°C for 2 hours, and then melt it in a heating furnace with a temperature of 755±5°C;

Preheat AlEr alloy, AlZr alloy, AlCu alloy, AlSi alloy and AlMn alloy at 230°C for 2 hours respectively, and then add them to the molten metal aluminum. After the alloy is completely melted, keep it at 755±5°C for 16 minutes;

When the temperature of the heat-preserved melt has dropped to 735±5°C, stir the melt evenly, preheat the slag-removing spoon at 250°C for 1 hour, then use the slag-removing spoon to remove the slag, and then add the covering agent, which is potassium chloride and sodium chloride mixed salt, wherein the percentage by weight of potassium chloride is 50%, and the addition of covering agent is 3% of the total weight of the melt;

Preheat the bell jar at 240°C for 1 hour, then put the metal magnesium into the bell jar, press the metal magnesium into the melt with the bell jar for 4 minutes, take out the bell jar, and keep it at 735±5°C for 35 minutes to obtain a molten alloy The amount of various metals and alloys is Mg 0.4%, Si 1.5%, Cu 0.7%, Mn 0.3%, Er 0.5%, Zr 0.2% according to the weight percentage of each element in the molten alloy, and the balance is Al, and the metal magnesium Add 80% in excess according to the amount added;

First preheat the bell jar at 240°C for 1 hour, then put solid hexachloroethane into the bell jar, press the solid hexachloroethane into the molten alloy to remove impurities with the bell jar, the amount of hexachloroethane is 4% of the total weight. After the molten alloy stops producing bubbles, the molten alloy is cooled to 700°C, and then poured into a crucible that has been preheated at 200±5°C for 2 hours to make a billet. After the molten alloy is solidified, an alloy billet is obtained;

Heat the alloy billet to 520±5°C for 14 hours, then cool it down to 430±5°C for 2 hours, and then carry out three passes of hot rolling at 430±5°C. The reduction in the first pass is controlled at 50%. After each pass of hot rolling, the alloy billet is held at 430±5°C for 13 minutes for recrystallization annealing, and then three passes of normal temperature cold rolling are carried out after hot rolling. The total reduction of hot rolling and cold rolling is required to be 89%. , to obtain rolled plate;

The rolled plate is kept at 540±5°C for 1h for solid solution, then quenched with room temperature water, and then heated to 180±5°C for 5h to obtain an AlMgSi alloy sheet, the composition of which contains Mg 0.4% and Si 1.5% by weight. Cu 0.7%, Mn 0.3%, Er 0.5%, Zr 0.2%, and the balance is Al; the tensile strength is 426.3MPa, the yield strength is 342.6MPa, and the elongation is 18%.

Example 3

Preheat metal aluminum at 240°C for 1 hour, and then melt it in a heating furnace with a temperature of 755±5°C;

Preheat AlEr alloy, AlZr alloy, AlCu alloy, AlSi alloy and AlMn alloy at 240°C for 1 hour respectively, and then add them to the molten metal aluminum. After the alloy is completely melted, keep it at 755±5°C for 18 minutes;

When the temperature of the heat-preserved melt has dropped to 735±5°C, stir the melt evenly, preheat the slag-removing spoon at 240°C for 1 hour, then use the slag-removing spoon to remove the slag, and then add the covering agent, which is potassium chloride Mixed salt with sodium chloride, wherein the percentage by weight of potassium chloride is 50%, and the addition of covering agent is 2.5% of the total weight of the melt;

Preheat the bell jar at 220°C for 2 hours, then put the metal magnesium into the bell jar, press the metal magnesium into the melt with the bell jar for 5 minutes, take out the bell jar, and keep it at 735±5°C for 30 minutes to obtain a molten alloy The consumption of various metals and alloys is Mg0.8%, Si 1%, Cu0.8%, Mn 0.2%, Er 0.2%, Zr 0.15% by weight percentage of each element in the molten alloy, and the balance is Al, and Metal magnesium is added in excess of 90% according to the amount added;

First preheat the bell jar at 220°C for 2 hours, then put solid hexachloroethane into the bell jar, press the solid hexachloroethane into the molten alloy to remove impurities with the bell jar, the amount of hexachloroethane is the molten alloy 5% of the total weight. After the molten alloy stops producing bubbles, the molten alloy is cooled to 690°C, and then poured into a crucible that has been preheated at 200±5°C for 2 hours to make a billet. After the molten alloy is solidified, an alloy billet is obtained;

Heat the alloy billet to 520±5°C for 12 hours, then cool down to 430±5°C and hold for 2 hours, then perform three passes of hot rolling at 430±5°C, the reduction of the first pass is controlled at 45%, After each pass of hot rolling, the alloy billet is held at 430±5°C for 12 minutes for recrystallization annealing, and then three passes of normal temperature cold rolling are carried out after hot rolling. The total reduction of hot rolling and cold rolling is required to be 85%. , to obtain rolled plate;

Heat the rolled sheet at 540±5°C for 2 hours for solid solution, then quench it with room temperature water, then raise the temperature to 180±5°C for 4 hours to obtain an AlMgSi alloy sheet, the composition of which contains 0.8% Mg and 1% Si by weight , Cu0.8%, Mn 0.2%, Er 0.2%, Zr 0.15%, the balance is Al; the tensile strength is 400.5MPa, the yield strength is 321.5MPa, and the elongation is 18%.

Example 4

Preheat metal aluminum at 250°C for 1 hour, and then melt it in a heating furnace with a temperature of 755±5°C;

Preheat AlEr alloy, AlZr alloy, AlCu alloy, AlSi alloy and AlMn alloy at 250°C for 1 hour respectively, and then add them to the molten metal aluminum. After the alloy is completely melted, keep it at 755±5°C for 20 minutes;

When the temperature of the melt after heat preservation is lowered to 735±5°C, stir the melt evenly, preheat the slag scraper at 230°C for 2 hours, then remove the slag with the slag scraper, and then add the covering agent, which is potassium chloride Mixed salt with sodium chloride, wherein the percentage by weight of potassium chloride is 50%, and the addition of covering agent is 2.5% of the total weight of the melt;

Preheat the bell jar at 200°C for 2 hours, then put the metal magnesium into the bell jar, press the metal magnesium into the melt with the bell jar for 4 minutes, take out the bell jar, and keep it at 735±5°C for 30 minutes to obtain a molten alloy The amount of various metals and alloys is Mg 0.6%, Si 1.3%, Cu 0.75%, Mn 0.1%, Er 0.1%, Zr 0.1% according to the weight percentage of each element in the molten alloy, and the balance is Al, and the metal magnesium Add 100% in excess according to the amount added;

First preheat the bell jar at 200°C for 2 hours, then put solid hexachloroethane into the bell jar, press the solid hexachloroethane into the molten alloy to remove impurities with the bell jar, the amount of hexachloroethane is the molten alloy 5% of the total weight. After the molten alloy stops producing bubbles, the molten alloy is cooled to 680°C, and then poured into a crucible preheated at 200±5°C for 1 hour to make a billet. After the molten alloy is solidified, an alloy billet is obtained;

Heat the alloy billet to 520±5°C for 10h, then cool down to 430±5°C for 1h, and then carry out three passes of hot rolling at 430±5°C, with the reduction of the first pass controlled at 48%. After each pass of hot rolling, the alloy billet is held at 430±5°C for 10 minutes for recrystallization annealing, and then three passes of normal temperature cold rolling are carried out after hot rolling. The total reduction of hot rolling and cold rolling is required to be 90%. , to obtain rolled plate;

The rolled plate is kept at 540±5°C for 1 hour for solid solution, then quenched with room temperature water, and then heated to 180±5°C for 4.5 hours to obtain an AlMgSi alloy plate, the composition of which contains Mg 0.6% and Si 1.3% by weight , Cu 0.75%, Mn 0.1%, Er 0.1%, Zr 0.1%, and the balance is Al; the tensile strength is 419.8MPa, the yield strength is 334.1MPa, and the elongation is 19%.

Claims (1)

1. A kind of AlMgSi alloy sheet material, it is characterized in that composition contains Mg 0.4～0.8% by weight percentage, Si 1～1.5%, Cu 0.7～0.8%, Mn 0.1～0.3%, Er 0.1～0.5%, Zr 0.1～0.2 %, the balance is Al; the tensile strength of the alloy sheet > 400MPa, the yield strength > 300MPa, and the elongation > 17%; the preparation method is carried out according to the following steps: (1) Preheat metal aluminum at 200~250°C for 1~2h, and then melt it in a heating furnace with a temperature of 755±5°C; (2) Preheat AlEr alloy, AlZr alloy, AlCu alloy, AlSi alloy and AlMn alloy at 200~250°C for 1~2h respectively, and then add them to the molten metal aluminum. Keep warm for 15~20min; (3) When the temperature of the melt after heat preservation is lowered to 735±5°C, stir the melt evenly, then remove the slag, and then add the covering agent. The amount of covering agent added is 2~3% of the total weight of the melt; (4) Use a bell jar to press magnesium metal into the melt for 3~5min, take out the bell jar, and keep it warm at 735±5℃ for 30~40min to obtain a molten alloy; the amount of various metals and alloys is based on the elements in the molten alloy The weight percentage is Mg 0.4~0.8%, Si 1~1.5%, Cu 0.7~0.8%, Mn 0.1~0.3%, Er 0.1~0.5%, Zr 0.1~0.2%, the balance is Al, and metal magnesium is added according to Add 80~100% in excess; (5) Use a bell jar to press solid hexachloroethane into the molten alloy. The amount of hexachloroethane is 4~5% of the total weight of the molten alloy. After the molten alloy stops producing bubbles, cool the molten alloy to 680~ 700°C, and then poured into a crucible that has been preheated at 200±5°C for 1~2h to make a billet, and obtain an alloy billet after solidification; (6) Heat the alloy billet to 520±5°C for 10~15h, then cool down to 430±5°C for 1~2h, then carry out three passes of hot rolling at 430±5°C, and then carry out three passes Cold rolling at room temperature requires a total reduction of 85-90% to obtain rolled plates; (7) Keep the rolled sheet at 540±5°C for 1~2h, then quench it with water at room temperature, and then raise the temperature to 180±5°C for 4~5h to obtain the AlMgSi alloy sheet.

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