JPH10110232A - Al-mg-si alloy sheet and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an Al-Mg-Si alloy sheet which is the sheet obtd. by subjecting the directly cast and rolled sheet of an Al-Mg-Si alloy to cold rolling as well and having a small secular change and high age hardenability by the control of the conditions in casting and rolling, cold rolling, heat treatment or the like. SOLUTION: This Al-Mg-Si alloy is the one obtd. by subjecting the directly cast and rolled sheet of an Al alloy having a compsn. contg., as essential elements, by mass, 0.2 to 3.0% Si and 0.2 to 3.0% Mg, one or >= two kinds among 0.01 to 0.5% Mn, 0.01 to 0.5% Cr, 0.01 to 0.5% Zr and 0.001 to 0.5% Ti, furthermore contg. one or >= two kinds among 0 to 2.5% Cu, 0 to 0.2% Sn and 0 to 2% Zn, in which the content of Fe is regulated to <=1.0%, and the balance Al with inevitable impurities to cold rolling as well. In this case, the maximum grain size in the metallic structure of this sheet is regulated to <=100μm, and the maximum length of continuous Mg2 Si compounds in the surface layer part is regulated to <=50μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an Al-Mg-Si alloy sheet having little change over time and excellent in bake hardenability, and a method for producing the same. Al-Mg-Si, a rolled plate of Al-Mg-Si alloy suitable for forming used in bending, press forming, etc., can be manufactured at a lower manufacturing cost compared to the prior art by direct casting and cold rolling. The present invention relates to a -Si alloy sheet and a method for producing the same. In this specification, the content of the additional element in the Al alloy means mass%, but this is simply described as%.

[0002]

2. Description of the Related Art Automobile exterior panels, chassis for home electric appliances, etc.
Al with excellent corrosion resistance and ductility, and age hardened by heating
In many cases, a -Mg-Si alloy sheet is formed into a predetermined shape, and then painted, baked and heated to age harden it into a product. However, Al-Mg- produced by the conventional production method
Reinforced Si based alloy sheet, by standing at room temperature after the solution treatment (natural aging), and GP zone precipitation, the baking heating time equivalent to beta 'referred Mg ₂ Si intermediate phase or of contributing to improving the strength in Since the precipitation of a phase is hindered, a material that has passed a long time after the solution treatment did not have sufficient strength after coating and baking heating. Further, the problem that the strength is increased with the precipitation of the GP zone and the ductility is remarkably reduced also occurred.

As a method for solving this problem, Japanese Patent Publication No.
A pre-aging treatment after solution treatment as shown in JP-A-7460, a restoration treatment as shown in JP-A-04-259358, and a combination thereof are devised. However, these treatments can increase the increase in strength at the time of painting and baking without impairing ductility, but there is a problem in that the number of steps increases the production cost. Conventional Al-Mg-Si alloy rolled sheets for molding and molded articles thereof are produced as described below, including the above-mentioned improved production method. In other words, these first produce an ingot of a predetermined alloy composition, this is subjected to facing and homogenization treatment,
Subsequently, it is manufactured by hot rolling, cold rolling (annealing as necessary), solution treatment, the above-mentioned preliminary aging treatment or restoration treatment, molding, and age hardening treatment (painting and baking heating). As described above, the conventional manufacturing method requires a very long process and also requires large-scale equipment, so that the manufacturing cost increases,
It is not always suitable for industrial production.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to suppress the GP zone that precipitates during natural aging by leaving at room temperature,
Al for molding with little change over time so that the strengthening phase precipitates quickly at the time of painting and baking and high bake hardening is obtained.
An object of the present invention is to obtain a -Mg-Si alloy sheet by combining a direct casting rolling method and a conventional cold rolling method, which can be manufactured at low cost due to extremely short steps. It is another object of the present invention to find such preferable manufacturing conditions. Here, the direct casting and rolling method referred to herein is the one shown in FIGS.
As shown in FIG.
Continuously, and immediately after the casting and solidification of the molten metal, it is rolled by the twin rolls 1 and 2 so that a long rolled plate is directly formed from the molten metal,
The coil is to be used. This method is generally called a hunter method, a direct rolling method or the like, which is different from a method of obtaining only a continuous cast plate, but is referred to as a direct casting rolling method in this specification. This manufacturing method
Conventionally, a process for forming an ingot or a cast plate, a homogenization process, a hot and cold rolling process, and the like are performed in one process, and there is an advantage that many processes can be omitted.

[0005]

Means for Solving the Problems According to the invention of claim 1 for solving the above-mentioned problems, the present invention relates to a method for manufacturing a semiconductor device comprising the steps of:
s%, the same applies hereinafter), Mg 0.2-3.0%, Mn 0.01-0.5
%, Cr 0.01 to 0.5%, Zr 0.01 to 0.5%, Ti 0.001 to 0.5%, or one or more of Cu 0 to 2.5%, Sn 0
0.2%, Zn 0-2.0%
Fe is controlled to 1.0% or less, the balance is a direct casting rolled plate of Al alloy consisting of Al and unavoidable impurities, further cold-rolled plate, the maximum crystal grain size of the metal structure of the plate is 100 μm An Al-Mg-Si alloy plate, wherein the maximum length of the continuous Mg ₂ Si compound in the surface layer portion is 50 μm or less,

[0006] The invention according to claim 2 is characterized in that:
Contains Si 0.2-3.0%, Mg 0.2-3.0%, Mn 0.01-0.5%,
Cr 0.01 to 0.5%, Zr 0.01 to 0.5%, Ti 0.001 to 0.5%
Species or two or more species, Cu 0-2.5%, Sn 0-
0.2%, Zn 0-2.0%
1.0% or less, the remainder is Al alloy melt consisting of Al and unavoidable impurities, using a direct casting and rolling device with twin rolls, under the condition that the rolling load P (ton) satisfies the following formula,
Casting and rolling directly to a plate with a thickness of 4 mm or less, and then 15%
Cold rolling at a rolling rate of less than 70% or more, followed by solution treatment in the range of 400 ° C to the melting temperature of the material, and cooling after solution cooling to 175 ° C or less at a cooling rate of 2 ° C / s or more It is quenched and then reheated to 180-320 ° C and held for 0-25 minutes.The maximum grain size of the metal structure of the plate is 100 μm or less, and the maximum length of the continuous Mg ₂ Si compound in the surface layer. A method for producing an Al-Mg-Si alloy sheet characterized by having a thickness of 50 μm or less, wherein: P ≧ 5.8 × 10 ^{−6 .t.w.D 1/2} .v .exp ｛1600 / ( (T + 273)｝ ・ (R / 100) ^-0.5 , where: t: exit side plate thickness (mm), w: exit side plate width (mm), D: roll diameter (mm), v: roll peripheral speed (mpm), T: Surface temperature of outlet plate (° C), R: Cold rolling reduction (%)

[0007] The invention according to claim 3 is the invention according to claim 2.
Under the same conditions as the molten aluminum alloy and the rolling conditions, it was directly cast and rolled into a plate with a thickness of 4 mm or less, then cold rolled at a rolling ratio of 15% or more and less than 70%, and subsequently melted at 400 ° C to the material. Solution treatment is performed in the temperature range, cooling after solution cooling is quenched at a cooling rate of 2 ° C / s or more to a range of 40 to 175 ° C, coiled at the above temperature, and the metal structure of the plate is cooled. Al-Mg- characterized in that the maximum crystal grain size is 100 μm or less and the maximum length of the continuous Mg ₂ Si compound in the surface layer is 50 μm or less.
This is a method for producing a Si-based alloy plate.

[0008] The invention according to claim 4 is characterized in that as an essential element
Contains Si 0.2-3.0%, Mg 0.2-3.0%, Mn 0.01-0.5%,
Cr 0.01 to 0.5%, Zr 0.01 to 0.5%, Ti 0.001 to 0.5%
Species or two or more species, Cu 0-2.5%, Sn 0-
0.2%, Zn 0-2.0%
1.0% or less, the remainder is Al alloy melt consisting of Al and unavoidable impurities, using a direct casting and rolling device with twin rolls, under the condition that the rolling load P (ton) satisfies the following formula,
Casting and rolling directly to a plate with a thickness of 4 mm or less, and then 70%
Cold-rolled at the above rolling ratio, followed by solution treatment in the range of 400 ° C to the melting temperature of the material, and cooling after solution cooling is performed at 2 ° C.
at 175 ° C or less at a cooling rate of
Reheat to 320 ° C and hold for 0 to 25 minutes to reduce the maximum crystal grain size of the metal structure of the plate to 100 μm or less and the maximum length of the continuous Mg ₂ Si compound on the surface layer to 50 μm or less A method for producing an Al-Mg-Si alloy plate, characterized by: P ≧ 2.9 × 10 ⁻⁶ t ・ w ・ D ^1/2 (R / 100) ^-0.5 However, t: Outgoing plate thickness (mm), w: Outgoing plate width (mm), D: Roll diameter (mm), v: Roll peripheral speed (mpm), T: Surface of outgoing plate Temperature (° C), R: Cold rolling rate (%)

According to a fifth aspect of the present invention, there is provided the method as set forth in the fourth aspect.
Under the same conditions as the Al alloy melt and rolling conditions, it is directly cast and rolled into a plate having a thickness of 4 mm or less, and then cold-rolled at a rolling rate of 70% or more, and then in the range of 400 ° C to the melting temperature of the material. In the solution treatment, the solution is cooled rapidly at a cooling rate of 2 ° C./s or more to a range of 40 to 175 ° C., coiled at the above temperature, and the maximum crystal grain of the metal structure of the plate is obtained. Diameter 100
A method for producing an Al-Mg-Si alloy sheet, wherein the maximum length of a Mg ₂ Si compound having a thickness of not more than μm and a continuous surface layer portion is not more than 50 μm.

[0010] Further, according to the invention of claim 6, after directly casting and rolling into a plate having a plate thickness of 4 mm or less, winding this into a coil shape,
6. The aluminum alloy according to claim 2, wherein a homogenization treatment (heating / cooling rate: 30 to 100 [deg.] C./hour) is performed at a temperature of 580 [deg.] C. or less for 2 to 24 hours, and then cold rolling is performed. -Mg-
This is a method for producing a Si-based alloy plate.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Among the above-mentioned inventions, the invention of claim 1 relates to a plate obtained by direct casting and cold rolling and the invention of claims 2 to 6 The present invention relates to a method for manufacturing the plate. Hereinafter, the respective inventions will be described in detail.

(1) Regarding the invention of claim 1 First, the reason why the alloy composition of the plate according to the present invention is limited as described above will be described. Si precipitates as an intermediate phase of Mg ₂ Si called β ′ together with Mg or a strengthening phase equivalent thereto during heating during painting and baking to improve the strength. The reason for limiting the addition amount to 0.2 to 3.0% is that if it is less than 0.2%, the effect is small, and if it exceeds 3.0%, the ductility after the solution treatment decreases. Mg forms a solid solution in the matrix after the solution treatment and contributes to improvement of ductility. In addition, as described above, during painting and baking heating, it precipitates as a reinforcing phase together with Si and improves the strength. The reason for limiting the addition amount to 0.2 to 3.0% is that if it is less than 0.2%, the effect is small, and if it exceeds 3.0%, the ductility after the solution treatment decreases. As described above, Si and Mg precipitate as a strengthening phase at the time of coating and baking heating, and improve the strength. If the abundance ratio of these two elements is different, their bake hardenability is also different, and the weight ratio of Si and Mg is Si> 0.6Mg
%, The amount of Si becomes excessive with respect to the amount of Mg ₂ Si, and more excellent bake hardenability is obtained. In addition, even if a small amount of Ag, Cd, or the like is added to control the aging behavior at the time of coating and baking heating, the effect of the present invention is not impaired.

Mn, Cr, Zr, and Ti are added to refine the crystal grains or improve the matrix strength. The addition of Mn 0.01-0.5%, Cr
One or more of 0.01 to 0.5%, Zr 0.01 to 0.5%, and Ti 0.001 to 0.5%. If each is less than the lower limit, the effect is small, and if it exceeds the upper limit, the ductility after the solution treatment is reduced.
Further, Cu, Sn, and Zn precipitate during heating during painting and baking to improve the strength. The addition of Sn also has the effect of improving the surface quality. The addition is, if necessary, Cu 0-2.5%, Sn 0
0.20.2%, Zn 0-2.0%. Here, 0% of each element means that it may not be added in some cases. Also, when adding, each element is 2.
The reason why the content is limited to 5% or less, 0.2% or less, and 2.0% or less is that if the content exceeds these limits, adverse effects such as a decrease in corrosion resistance and an increase in quenching sensitivity are caused. Fe is usually contained as an impurity of Al. However, Fe is easy to form a compound with Si, and if it exceeds 1.0%, it hinders improvement in strength during heating during painting and baking. It should be noted that B or the like, which is usually added as a material for refining the cast structure, does not particularly impair the effects of the present invention as long as it is added in an amount of 0.1% or less.

Next, the reason why the maximum crystal grain size in the metal structure of the rolled sheet of the present invention is set to 100 μm or less is that if it exceeds 100 μm, sufficient ductility cannot be obtained as a molding material, and that the surface becomes rough after forming. This is not preferable as a molding material, for example. Further, in the metallographic structure of the surface layer of the rolled sheet according to the present invention, the reason why the maximum length of the continuous Mg ₂ Si compound is set to 50 μm or less includes Mg or Si whose maximum length exceeds 50 μm. This is because when the coarse main solute-based compound is already precipitated before painting / baking, the amount of solid solution is insufficient, and the strength at the time of painting / baking heating is not sufficiently improved. The thickness of the rolled plate according to the present invention is about 0.7 to 3 mm. The content of the Al-Mg-Si alloy sheet according to the present invention is as described above. As is clear from the examples described later, such a rolled sheet has an elongation of 27% or more before painting and baking heating. The moldability is excellent, and the strength (YS) is improved by 100 MPa or more in the heating at the time of painting and baking after molding as compared to before heating, and is suitable for molding materials for various uses as described above.

(2) Regarding the Inventions of Claims 2 and 3 The inventions of Claims 2 and 3 relate to the method of manufacturing a rolled sheet according to the invention of Claim 1 above.
This is manufactured by cold rolling or heat treatment. This direct casting and rolling method of the present invention will be described specifically with reference to the drawings.
The Al alloy melt 4 according to claim 1 is continuously supplied between the twin rolls 1 and 2 through the nozzle 3 by using a direct casting and rolling device using twin rolls as shown in FIGS. 1 and 2. From the tip B of 3 to the closest point A of the twin rolls 1 and 2
In the meantime, casting and solidification are performed, and rolling is performed near point A. In FIG. 2, point C is the final solidification point of the molten metal. The present invention relates to a directly cast rolled plate manufactured in this way,
Furthermore, after performing cold rolling and solution treatment, it is quenched, and then reheat treatment (claim 2) or high-temperature coil winding (claim 3) is performed.

In these production methods, the processes required to control the metal structure, such as solidification by DC casting and plastic working by hot rolling, are realized by a single twin roll direct casting and rolling. It is very important to appropriately determine the conditions for direct casting and rolling with the twin rolls. In order to find such conditions, the relationship between the conditions of twin roll direct casting and rolling and the metal structure and mechanical properties was energetically studied from a basic viewpoint, and as a result, the rolling load P (ton ) To the following equation: P ≥ 5.8 × 10 ^-6 · t · w · D ^1/2 · v · exp ｛1600 / (T + 273)｝ · (R / 100) ^-0.5 where t: exit side plate Thickness (mm), w: Outer width (mm), D: Roll diameter (mm), v: Roll peripheral speed (mpm), T: Surface temperature of outlet side (° C), R: Cold rolling rate (%) After directly casting and rolling into a plate with a thickness of 4 mm or less under conditions that satisfy the conditions, cold rolling of 15% or more and less than 70%, followed by solution treatment in the range of 400 ° C to the melting temperature of the material, It has been found that it is possible to manufacture an Al-Mg-Si alloy sheet having the same performance as the conventional method by rapidly cooling the subsequent cooling to 175 ° C or less at a cooling rate of 2 ° C / s or more. . Here, the rolling load P (ton) is set as: P ≧ 5.8 × 10 ^-6・ t ・ w ・ D1 ^{/ 2}・ v ・ exp ｛1600 / (T + 273)｝ ・ (R / 100) ^-0.5 This is because, with a rolling load smaller than this, the amount of plastic deformation from the end of solidification is insufficient, the crystallization phase is not sufficiently separated, and the elongation is reduced as compared with the case of manufacturing by the conventional method, The smaller the final cold rolling reduction, the greater the reduction required. Note that this conditional expression is for the case where the rolling reduction during the cold rolling in the subsequent step is 15% or more and less than 70%. The cooling rate after direct casting and rolling is not particularly limited,
In order to sufficiently exert the effect of the subsequent solution treatment, it is desirable to cool at a rate as high as possible.

The reason why the cold rolling rate is set to 15% or more is that if it is less than 15%, the pulverization of the structure generated at the time of solidification is not sufficiently performed.
The reason why the ductility is reduced is that the upper limit is set to less than 70% because, in the case of a cold rolling reduction exceeding 70%, the conditional expression of the rolling load during direct casting and rolling is different from that described above. is there.
The solution treatment temperature was set to 400 ° C or higher to dissolve Mg and Si in a solid solution. At a cooling rate of 2 ° C / s or more, the temperature was set to 175 ° C.
Rapid cooling to the following temperature is due to the solid solution before cooling.
The primary purpose is to improve the strength by dissolving supersaturated solid solution without causing precipitation of additional elements such as i and Mg as much as possible, and precipitating a fine reinforcing phase at the time of subsequent coating and baking heating. If the cooling rate is lower than 2 ° C./s or the temperature is higher than 175 ° C., coarse compounds are precipitated during the cooling, so that the elongation is reduced.

In the production method according to the second and third aspects of the present invention, after the above-mentioned solution treatment, it is rapidly cooled to 175 ° C. or less at a cooling rate of 2 ° C./s or more, and then reheated to 180 to 320 ° C. To hold for 0 to 25 minutes (claim 2: restoration processing)
Alternatively, after the above-mentioned solution treatment, it is necessary to rapidly cool to a range of 40 to 175 ° C. at a cooling rate of 2 ° C./s or more, and wind up in a coil shape at the above temperature (Claim 3: High temperature coil winding). Although it is possible to produce a plate with almost the same performance as the plate obtained in the conventional process by the above-mentioned process, the GP zone is precipitated by natural aging as in the conventional method, and painting and baking is performed. This is because there is a problem that the strength after heating cannot be sufficiently obtained, or the strength is increased and the moldability is significantly reduced. Also in the case of direct casting and rolling by twin rolls, it is necessary to suppress the generation of the GP zone due to natural aging by the above-described restoration treatment or high-temperature coil winding as in the conventional method.

According to a second aspect of the present invention, after the solution treatment, the solution is rapidly cooled to a temperature of 175 ° C. or less, and then reheated (restored). Heating is carried out to maintain the temperature for 0 to 25 minutes, and then the mixture is allowed to cool to room temperature. Here, holding for 0 minutes means not to hold, that is, to cooling without holding when the temperature reaches 180 to 320 ° C. This reheating treatment is usually preferably performed in a continuous annealing furnace (CAL). According to a third aspect of the present invention, after the solution treatment as described above, the solution is rapidly cooled to a temperature of 40 to 175 ° C., wound around a coil in this temperature range (high-temperature coil winding), and then left at room temperature. In the processing after winding the high-temperature coil, the winding coil may be left at room temperature and allowed to cool, or the winding temperature (40 to 175).
C) in a furnace for up to 36 hours and then allowed to cool. Further, after winding the coil at a high temperature, the coil may be left at room temperature for a while, then kept in a furnace at 40 to 175 ° C. for 36 hours, and then allowed to cool. For the treatment after the high-temperature winding, a conventionally known method for the Al-Mg-Si alloy material is applied as necessary. The reason why there is a range in the heat treatment conditions of the restoration processing and the high-temperature coil winding processing is that a predetermined performance cannot be obtained even if the heat treatment is less than the lower limit or exceeds the upper limit. Further, there is no particular restriction on the room temperature standing time from the quenching to the execution of the restoring treatment after the solution treatment, and the effect is not impaired even if the restoring treatment is performed after leaving for several months or more.

(3) Regarding the Inventions of Claims 4 and 5 The inventions of Claims 4 and 5 relate to another method of manufacturing a rolled plate according to the invention of Claim 1. That is, in the production method according to claims 2 and 3, the cold rolling reduction after direct casting and rolling exceeds 70%. In this case, the rolling load P (ton) applied to the twin rolls is represented by the following formula: ： P ≧ 2.9 × 10 ^-6・ t ・ w ・ D ^1/2・ v ・ exp ｛1600 / (T + 273)｝ ・ (R / 100) ^-0.5 where t: Outer side plate thickness (mm), w : Outlet plate width (mm), D: Roll diameter (mm), v: Roll peripheral speed (mpm), T: Surface temperature of the outlet plate (° C), R: Cold rolling rate (%), Claim 2, As compared with the case described in No. 3, the condition relating to the rolling load is changed. It has a cold rolling rate of 70%
Is exceeded, the crystallization phase is separated during the cold rolling, so that it is not necessary to increase the rolling load during direct casting and rolling as in the second and third aspects. Further, as the final cold rolling reduction is smaller, a larger reduction is required as in the case of the second and third aspects. The conditions, significance, effects, etc. of the solution treatment, quenching, restoration treatment (Claim 4) or high-temperature coil winding (Claim 5) after cold rolling are the same as those described in Claims 2 and 3. It is.

(4) Regarding the invention of claim 6 According to the invention of claim 6, in the production method according to claims 2 to 5, the steel is directly cast and rolled and wound into a coil, and the coil is homogenized. This is a manufacturing method for performing cold rolling.
Such a homogenization treatment is carried out for the purpose of eliminating solidification segregation of a directly cast and rolled sheet and precipitating dispersed phase particles containing a transition element, whereby it is possible to improve ductility and strength. The homogenization conditions were set at 580 ° C
Keep at the following temperature for 2 to 24 hours (heating / cooling rate 30 to 100 hours)
° C / hour) in order to obtain the above-mentioned desired characteristics.

As described above, according to the present invention, it is possible to manufacture an Al-Mg-Si alloy sheet having a small change over time and excellent in bake hardenability at low cost. As with the conventional method, restoration processing or high-temperature winding to suppress natural aging is required, but ingot making, face milling,
Since the steps of homogenization, hot rolling, cold rolling and the like are greatly simplified, the total production cost is greatly reduced.

[0023]

Next, the present invention will be described in more detail with reference to Examples (Examples of the present invention) and Comparative Examples. Of the composition shown in Table 1
The molten Al-Mg-Si alloy was made into a plate by a direct casting and rolling device using a horizontal twin roll shown in FIGS. 1 and 2, and the plate was further cold-rolled to produce a plate having a thickness of 0.7 to 3 mm. Table 2 shows the details of the manufacturing conditions.

[0024]

[Table 1]

[0025]

[Table 2]

With respect to the plate material thus manufactured, the maximum crystal grain size in the metal structure of the plate was measured with an optical microscope. The maximum length of the continuous Mg ₂ Si compound on the surface layer was measured by observing a reflected electron image using a scanning electron microscope. Further, after standing at room temperature for 1, 5, 20, and 60 days after production, a tensile test was performed. Tensile tests were also performed after heating at 175 ° C for 60 minutes, which simulated painting and baking heating. In the tensile test, tensile strength, proof stress, and elongation were measured using a JIS No. 5 tensile test piece. Table 3 shows the results.

[0027]

[Table 3]

As is evident from Table 3, in the rolled sheet of the present invention and the method for producing the same (AG), the yield strength by heating during coating and baking is large (100 MPa or more), and the ductility (elongation) before heating is also high. It can be seen that they are excellent (27% or more), and that these characteristics are excellent in stability when left at room temperature. On the other hand, Comparative Example (HN), which deviates from the composition specified in the present invention or deviates from the production conditions of the present invention, has a small increase in proof stress before and after heating, or is inferior in terms of ductility (elongation) before heating. You can see that there is.

[0029]

As described above, according to the Al-Mg-Si-based alloy sheet and the method for producing the same according to the present invention, the precipitation of the GP zone during natural aging is suppressed, and the coating is quickly heated by baking. An Al-Mg-Si-based alloy sheet having a precipitation hardening phase, a small change with time, and a high age hardening property can be obtained at low cost, and has an industrially remarkable effect.

[Brief description of the drawings]

FIG. 1 Direct casting and rolling equipment (cross section) using horizontal twin rolls
FIG.

FIG. 2 is an enlarged detail view of a portion D in FIG. 1;

[Description of Signs] 1 Upper Roll 2 Lower Roll 3 Nozzle 4 Molten Metal 5 Direct Cast Rolled Plate A Center Line of Twin Roll (Closest Point of Roll) B Tip of Nozzle C Final Solidification Point of Molten Metal

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI C22F 1/00 685 C22F 1/00 685 686 686B 691 691B 692 692A 692B 694 694A (72) Inventor Tetsushi Kakiu Marunouchi 2 Chiyoda-ku, Tokyo 6-1-1, Furukawa Electric Co., Ltd. (72) Inventor Minoru Hayashi 2-6-1, Marunouchi, Chiyoda-ku, Tokyo In-house Furukawa Electric Co., Ltd. (72) Inventor Yoichiro Toji 2 Marunouchi, Chiyoda-ku, Tokyo 6-1-1 Furukawa Electric Co., Ltd. (72) Inventor Koichi Hashiguchi 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Engineering Co., Ltd. (72) Inventor Masao Yukimoto, Chiba-shi, Chiba 1 Kawasaki-cho, Ward, Kawasaki Steel Corp.

Claims (6)

[Claims] Claims 1. An essential element containing Si 0.2 to 3.0% (mass%, the same applies hereinafter), Mg 0.2 to 3.0%, Mn 0.01 to 0.5%, Cr
Contains one or more of 0.01 to 0.5%, Zr 0.01 to 0.5%, Ti 0.001 to 0.5%, Cu 0 to 2.5%, Sn 0 to 0.
2%, Zn 0-2.0%
Restricted to 1.0% or less, the balance consists of Al and inevitable impurities
A directly cast and rolled sheet of an Al alloy, further cold-rolled, wherein the maximum grain size of the metal structure of the sheet is 100 μm or less, and the maximum length of a continuous Mg ₂ Si compound in the surface layer portion. But
An Al-Mg-Si-based alloy plate having a thickness of 50 µm or less. (2) Si 0.2 to 3.0% as an essential element, Mg 0.2 to
Including 3.0%, Mn 0.01-0.5%, Cr 0.01-0.5%, Zr 0.0
1 to 0.5%, one or more of Ti 0.001 to 0.5%, and one of Cu 0 to 2.5%, Sn 0 to 0.2%, Zn 0 to 2.0%
Including the seed or two or more, Fe is regulated to 1.0% or less, the balance of Al alloy melt consisting of Al and unavoidable impurities, using a twin-roll direct casting and rolling equipment, the rolling load P (ton) below Under the condition satisfying the following formula, directly cast and rolled into a plate having a thickness of 4 mm or less, and then cold-rolled at a rolling ratio of 15% or more and less than 70%, and then in the range of 400 ° C to the melting temperature of the material After solution treatment, the solution was cooled rapidly to 175 ° C or less at a cooling rate of 2 ° C / s or more, then reheated to 180-320 ° C and held for 0-25 minutes. Al characterized in that the maximum crystal grain size of the metal structure is 100 μm or less, and the maximum length of the continuous Mg ₂ Si compound in the surface layer is 50 μm or less.
-Manufacturing method of Mg-Si alloy sheet. ： P ≧ 5.8 × 10 ^-6・ t ・ w ・ D ^1/2・ v ・ exp ｛1600 / (T + 273)｝ ・ (R / 100) ^-0.5 where t: Outer side plate thickness (mm), w : Outlet plate width (mm), D: Roll diameter (mm), v: Roll peripheral speed (mpm), T: Surface temperature of outlet plate (° C), R: Cold rolling rate (%) 3. Casting and rolling directly into a plate having a thickness of 4 mm or less under the same conditions as those of the molten aluminum alloy and the rolling conditions according to claim 2, and then cold rolling at a rolling reduction of 15% or more and less than 70%. Rolling, followed by solution treatment at a temperature in the range of 400 ° C to the melting temperature of the material, and cooling after solution cooling is performed at a cooling rate of 2 ° C / s or more at 40 to 40 ° C.
It is quenched to a temperature of 175 ° C and wound up in a coil at the above temperature, and the maximum crystal grain size of the metal structure of the plate is 100 μm or less,
And the maximum length of the continuous Mg ₂ Si compound on the surface layer is 50 μm
A method for producing an Al-Mg-Si-based alloy sheet, comprising: 4. Si 0.2-3.0% as essential elements, Mg 0.2-
Including 3.0%, Mn 0.01-0.5%, Cr 0.01-0.5%, Zr 0.0
1 to 0.5%, one or more of Ti 0.001 to 0.5%, and one of Cu 0 to 2.5%, Sn 0 to 0.2%, Zn 0 to 2.0%
Including the seed or two or more, Fe is regulated to 1.0% or less, the balance of Al alloy melt consisting of Al and unavoidable impurities, using a twin-roll direct casting and rolling equipment, the rolling load P (ton) below Casting and rolling directly into a plate with a thickness of 4 mm or less under the conditions satisfying the following formula, and then cold rolling at a rolling rate of 70% or more, and then solution treatment in the range of 400 ° C to the melting temperature of the material And cooling after solution cooling at a cooling rate of 2 ° C / s or more for 175
Cool rapidly to below ℃, then reheat to 180-320 ℃
Hold for 25 minutes, and determine the maximum crystal grain size of the metal structure of the plate.
100 [mu] m or less, and Al-Mg-Si-based method for producing alloy sheet, wherein the maximum length of consecutive Mg ₂ Si compounds of the surface layer portion and 50μm or less. ： P ≧ 2.9 × 10 ^-6・ t ・ w ・ D ^1/2・ v ・ exp ｛1600 / (T + 273)｝ ・ (R / 100) ^-0.5 where t: Outer side plate thickness (mm), w : Outlet plate width (mm), D: Roll diameter (mm), v: Roll peripheral speed (mpm), T: Surface temperature of outlet plate (° C), R: Cold rolling rate (%) 5. Casting and rolling directly into a sheet having a thickness of 4 mm or less under the same conditions as the molten aluminum alloy and rolling conditions according to claim 4, and then cold rolling at a rolling rate of 70% or more, Subsequently, solution treatment is performed in the range of 400 ° C to the melting temperature of the material,
Cooling after solution cooling is quenched at a cooling rate of 2 ° C / s or more to a range of 40 to 175 ° C, coiled at the above temperature, and the maximum crystal grain size of the metal structure of the plate is 100 μm or less, and A method for producing an Al-Mg-Si alloy sheet, wherein the maximum length of a continuous Mg ₂ Si compound in a surface portion is 50 μm or less. 6. Casting and rolling directly into a plate having a thickness of 4 mm or less, winding this into a coil shape, and then heating at a temperature of 580 ° C. or less for 2 to 4 mm.
Homogenization treatment for 24 hours (heating / cooling rate 30 ~ 100 ℃ /
Time), and then cold rolling is performed. The method for producing an Al-Mg-Si alloy sheet according to claim 2, wherein: