JPS59157251A - Aluminum alloy flat bar for forming and its production - Google Patents

Abstract

PURPOSE:To obtain an Al alloy flat bar having excellent formability by preparing an Al alloy contg. a specific ratio of Zn, Fe, Cu, Mg and Mn and rolling the alloy under specific conditions. CONSTITUTION:An Al alloy contg., by weight %, 0.05-1% Zn, 0.25-0.7% Fe, 0.05-0.5% Cu, 0.5-2.5% Mg, 0.5-2.0% Mn and contg. Fe% + (Mn%X1.07)+ (MgX0.27)<=2.7 is cast to >=100mm. thickness. Such casting ingot is soaked at >=530 deg.C, is hot-rolled and is then heated at a heating rate of >=100 deg.C/min to 400-600 deg.C after or wighout cold rolling. The heated alloy is cooled to <=150 deg.C at a cooling rate of >=100 deg.C/min right after the heating or after holding within 10min to adjust the average crystal grain size to <=25mu and to maintain the component constributing to hardening by baking to a solid soln. state. Such alloy is subjected to >=10% cold rolling to >=99% total draft of the hot and cold rolling.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aluminum alloy sheet strip for forming and a method for manufacturing the same, and more particularly to a hardened 1=1 hardened aluminum alloy sheet strip for cans having particularly excellent formability and its manufacturing method. This relates to a manufacturing method.

In general, there are three types of aluminum alloy compound materials for can bodies: can bodies, can ends, and can tabs.In particular, aluminum alloys for can bodies are required to have the following properties: (1) drawing strength; , excellent re-drawability. (2) Poor ironing workability. (3
) ・j Scoring property (This is excellent. (・1)
Doming addition] duality (this is excellent. (5) Appearance is beautiful. (6) Being crushed by sleeping characteristics. (
7) A lever with excellent 7-run song performance.

(8) Deep draw ears are low. (9) Excellent pressure resistance. (10) Excellent buckling strength.

(11) It has excellent corrosion resistance.

For aluminum alloy can body materials, in order to make the weight of the can more effective through thinner walls, the thickness of the can wall must be adjusted as much as possible within a range that does not cause problems in can strength such as buckling strength. It is necessary to make it thin.

To achieve this, it is necessary to (1) improve the ironing properties, and furthermore, since a decrease in wall thickness will reduce the elongation and run properties, it is necessary to (2) improve the 7 run properties;
In addition, for can-end use, in order to increase the effect of thinning the wall, (3) rivet formability is required, and for tough use, in order to achieve the same effect as for end use. (4) The song must have a sexual orientation.

Among the above items, it is especially necessary to improve the flan song properties and improve the rivet formability.
These characteristics are necessary for molding that requires elongation in a minute range, that is, local elongation.

The inventor of the present invention has conducted research on aluminum alloys for manufacturing cans as explained below, and has determined to limit the amount of intermetallic compounds contained in normal cans in order to avoid stress concentration in the aluminum alloy that is the raw material. I realized that this is necessary. However, in the ironing process of the can body made of can materials, the above intermetallic compounds are added.
It has an excellent effect of preventing build-up.
Yes, an intermetallic compound of an appropriate size becomes a nucleus during recrystallization, so it is effective to reduce the crystal grain size to, for example, 25μ or less. They also found that it is desirable to have

The present invention has been made based on the fact that aluminum alloys as explained in Section 2 are excellent as materials for can bodies, and on the numerous findings of the inventor. In aluminum alloys for can ends and can tabs, the workability of ladder outer doors, running properties, and riveting properties are particularly improved, making it possible to further reduce the weight of cans.For large barrel forming processing. The present invention provides an aluminum alloy sheet and strip and a method for manufacturing the same.

The aluminum alloy sheet strip for forming and the manufacturing method thereof according to the present invention includes (1,) ZnO, 05 to 1 ust%.
, FeO,2-0,7ult,%, CuO,05-
0.5vL%, IVL80.5-2.5u+L%, Mn
Contains O,5-2,Oxut%, F″eu+L
%+(Mε田LしX 1.07)+(へ18Illt%
1\1 alloy where
%, and the size of each intermetallic compound is 45μ or less, and further, the rolled plate surface has an average width of crystal grains of 25μ or more]ζ. This invention is an aluminum alloy hard plate strip for use in
2) Zn 0905-1+ut%, FeO, 25-
0.7tlIL%, CLI 0.05-0.5u1t%
, MH, '0.5-2.5u+t%, Mn 0.5-2
．． OL, including lIt%, g, pewL% ten (M n
u+t%X1.07)+λ4gfieldL%X,27)≦2
．． After melting the A1 alloy of No. 7, it is cast to a thickness of 100 +n+, + or more, and the ingot is subjected to soaking treatment at 530 ° C or higher, and then cold rolled after hot rolling, or zu, 4
Heating at a heating rate of 100°C/min or more to a temperature of 00 to 600°C, and then heating to 150°C immediately after heating, or after holding for less than 10 minutes, at a cooling rate of 100°C/hour or more. After cooling to a temperature below, the average grain size is reduced to 25μ or less, and the components contributing to bake hardening are brought into a solid solution state, and cold rolling is performed to a rate of 10% or more, resulting in a total rolling reduction of 99.
A second invention provides a method for manufacturing a bake-hardened aluminum alloy hard plate strip, characterized in that the hardening process is less than or equal to %.
ZnO, 05-but%, FeO, 25-0,t%, CuO, 05-0,5uIL%, MB 0.5-
Contains 2.5uI 1%, MnO, 5-2,0+II 1%, and Fe u+L%+(MnuL%X], 07)+
(MBIIIL%xo, 27) = 2.0 to 3.0 A1 alloy plate is melted and then rapidly cooled and continuously cast to a thickness of 50III111 or less, with or without hot rolling. The strip ingot is heat treated or not at a temperature of 300°C, then cold open rolled or not, and then heated to a temperature of 400 to 600°C for 1 (
Heating at a heating rate of 10/min or more, and immediately after heating, or after holding for less than 10 minutes, cooling to 150°C or less at a cooling rate of 100°C/hour or more to reduce the average crystal grain size to 25μ or less. At the same time, the components that contribute to hardening are kept in a solid solution state, and cold rolling is further performed for 10% or more, so that the alloy rolling ratio of hot rolling and cold rolling is 90% or more. The present invention consists of three inventions, the third invention being a method for manufacturing a hardened aluminum cum alloy hard plate strip characterized by the following.

The aluminum alloy sheet strip for forming and machining according to the present invention and the method for manufacturing the same will be explained in detail.

First, an aluminum alloy sheet strip for forming according to the present invention)
I will now explain its content and component ratio.

Zn improves the 7 run/wringing properties and drawing properties after drawing and stamping 1), and the gradient formability after stretching, and
This Zn content 1. j: Rolled plate surface (MnFe
) No\16 to reduce the size of the crystallized metal fill compound,
Furthermore, it has the effect of improving the dislocation structure after undergoing plastic processing such as drawing, stretching, and ironing, so it is an element that further improves the 7-run song property and riveting property, and the Zn content is 0.05 wt% or less. 'J does not have such an effect, and if it is contained in excess of 1u+L%, although it shows a young fruit in terms of moldability, the corrosion resistance decreases greatly, and in reality, the corrosion resistance is reduced by γ in the coating. ensure, especially
Can bodies are painted after molding, so there are fewer problems, or in the case of can ends, molded after painting, it is desirable that the throat material has good corrosion resistance. Therefore, the Zn content is set to 0.05 to 1 ust%.

'Fe forms an intermetallic compound of (Fe-Mu) A16 with Mn, and is an element necessary to prevent the die from burning - f = 1 during ironing, and the content is 0.211I.
This effect is small below L%, and Q, 7u+t%
If the content exceeds 100%, it becomes easy to form a giant compound.

Therefore, the Fe content is set to 0.2 to Q, 7u+t%.

Cu is IV4. Is it necessary to contain it at the same time? 818
A solid solution is formed during baking with A.
I Ckl-b An element that generates and hardens precipitates and improves strength, and contains N, 4tO, 0
If it is less than 5u+L%, the effect described in "2" cannot be expected, and
If the content exceeds 0.5u+L%, the above-mentioned effects are satisfied, but the corrosion resistance as a 4.1 material for canvas bodies is greatly deteriorated. Therefore, the Cu content is 0.05 to 0.5
+IIL%.

hq8 needs to be contained simultaneously with Cu, and CL
After forming a solid solution with I by forming 78 bodies, precipitation hardening occurs, and
Cambody L gives the necessary strength as a material of A:1, and since it does not deteriorate corrosion resistance as much as Cu, it should be included in a large amount.
This effect is small in I, and in order to make the wall thinner and lighter by increasing the strength, it is necessary to contain 0.5% or more of needles. , the formability such as overhang is reduced, and scoring is more likely to occur.
Coinciding with the effect of improving the succeeding squaw link property of precipitates due to M11 content, which will be described later, even if the M content is increased, the canvas body exhibits excellent properties, but the M11 content is 2.511IL. If it exceeds %, moldability such as squeezing property and stretchability will be reduced, and the occurrence of scoring will become significant.

Therefore, the N4ε content is set to 0.5 to 2.5a+t%.

Unlike Mn IiCu and Mg, it does not contribute to precipitation hardening, or it is an important element that gives strength along with 1g, and MI+ precipitates together with At and MnA1, so it prevents sulfuring. However, the same as Mn 1.th record 11. When the porcelain is contained, in the recrystallization after heat treatment,
It stabilizes the texture and stabilizes the deep-drawn selvage, and this effect cannot be expected if the content is less than O, 5u + 1%, and if the N'111 content increases, the amount of crystallized substances will decrease. Increases in size and exceeds 2, Quit% i
If this happens, large pieces are likely to form, causing pinholes or breakage during ironing. Therefore,
The I11 content is 0.5 to 2.0 LIIL%.

Furthermore, the reason why Feu + t% + (Mnu + t% is produced during solidification during casting, and ()1 precipitates are those that become supersaturated during casting and are produced in the solid during subsequent heat treatment, and the precipitates are usually smaller than 1μ in size. Therefore, stress concentration + 4 units K (is not a particular problem.Then, if the crystallized substances are further classified, they are divided into the initial compound, which is generated just before solidification in the liquid, and the eutectic compound, which is formed during solidification. 1. (Primary compounds tend to grow into giant compounds.) In the secondary production process, there is also zonation of the molten metal, and in practice, the passage time of the formation temperature that depends on the growth. Is the influence of ′, the above formula)
Within the defined range, moldability can be improved by preventing the formation of macrocompounds.

The area occupancy rate of intermetallic compounds as seen from the surface of the rolled plate is 0.5.
The reason why it is set at ~5% is that if it is less than 0.5%, there is a problem that the die will be burned during the ironing process, and also,
This is because if it exceeds 5%, formability such as seven-run songability and rivetability will be extremely reduced, and pinholes will easily occur even during ironing.

The reason why the size of the intermetallic compound is set to be 45μ or less is because, as will be explained in the examples below, when the repulsion length is less than about 40μ, 7-run cracks occur frequently, and This is because breakage is likely to occur during processing. However, in rolled plates manufactured from industrial-grade large ingots, there are countless intermetallic compounds, and with a very small probability, large compounds may also be present. Therefore, the size of the intermetallic compound is set to be 45 μm or less.

The reason why the average width of crystal grains across the rolled plate surface is set to 25μ or less is to compensate for the decrease in various formability due to the thinning of the canvas body, and the decrease in necking properties due to high strength after baking. Furthermore, this is to promote precipitation hardening, and when the crystal grain size is reduced, formability, extensibility,
7. Lancing properties and ironing properties are improved, and drawing properties do not become a problem when thinning the wall, or wrinkles tend to occur. However, the second wrinkle occurs when the average crystal grain size becomes 25 μm or less, and TJ becomes +. In addition, when the average grain size exceeds 25μ, there is no difference from the conventional 4J material for canvas bodies,
It becomes difficult to increase the strength of thin walls. Therefore, the average grain size is 2
It should be 5μ or less.

Next, a method for manufacturing an aluminum alloy sheet strip for forming according to the present invention will be explained.

First, FeIIIt%+(Mn u+t%x1.07)
+(Mg urL%X0.27)≦2.7A1
The reason why alloys are produced in 1H increments of 1.0011 mm or more is that when the composition is smaller than the value of the above formula, the size of each compound becomes smaller and its appearance becomes smaller, which is favorable for Franson properties. In this case, a method using water cooling, which is an industrial casting method (in this case,
If the casting thickness becomes thinner than a certain level, the cooling rate during solidification becomes too high, the formation of products is suppressed, and the surface occupied by intermetallic compounds after rolling becomes too small (fL'), which is undesirable. The casting thickness should be 100 mm or more.

The ingot described above is soaked at a temperature of 530'C or higher, but if the soaking temperature is lower than 530'C, Mn
Since the precipitates of Δ16 become very fine and precipitate in large quantities, grain boundary movement at the time of recrystallization of the rolled plate is suppressed, the recrystallization temperature is increased and the crystal grains are coarsened, and
The texture of the recrystallization changes, causing 45° edges in the rolling direction during deep drawing, and long-term curling during ironing, which particularly affects ironing workability and deep drawability. In order to further improve the temperature, soaking treatment is carried out at 530° C. or higher.

The hot rolling after this soaking treatment does not require particular control of the hot full rolling amount, temperature, etc., and may be hot rolling using a normal industrial method, followed by cold rolling if necessary. It is then heated (annealed).

This heating (annealing) is performed at a temperature of 400 to 600°C, and this heating (annealing) recrystallizes the material, forming an iQ crystal aggregate fiber, making the deep drawing selvage small and stiff, and recrystallizing the crystal grains to make them finer and finer. , uniformity, and further sintering by precipitation hardening of Al-Cu-(CLI) to obtain 71 hardening.
1) The effect of solutionization can be obtained at temperatures below 400°C.The higher the temperature, the better, but there are trade-offs such as Cu content and storage time, but temperatures above 430°C A temperature of '4 is preferable, and the higher the temperature, the more recrystallized grains grow.
L<It is impossible to reduce the crystal grain size to 25μ or less. Therefore, the heating temperature is set to 400 to 600°C. In addition, the heating rate needs to be rapid in order to make the crystal grains fine and to reduce the formation of MgO on the plate surface due to the short processing time. Can not.

Next, it is necessary to control the holding time especially from the point of view of grain refinement. In other words, since it is a high-temperature treatment, is it possible to achieve the purpose even with a holding time of zero? Depending on the case, it may be necessary to hold it for a certain period of time depending on the ingredients contained, the ratio of ingredients, and the manufacturing conditions of the pond, but if you hold it at 1% temperature for a long time, recrystallized grains will grow and grain refinement will occur. to interfere with the situation. Therefore, the holding time is set to zero or 10 minutes.

Furthermore, the cooling rate needs to be controlled to obtain precipitation hardening, i.e., a slow cooling rate will cause precipitation during the cooling stage and optical precipitation hardening during baking. At a relatively low temperature during the cooling stage, the precipitates are small and contribute to improving the strength, or in this case, the strength increases before the final forming of the ladder and reduces the formability.For this reason, it is necessary to increase the cooling rate. There is, ]OO'C/
If it is longer than 1 hour, it is sufficient as a canvas material. However, a cooling rate higher than this may be acceptable, or air cooling is preferable for film cooling. Furthermore, the temperature must be lowered to a certain level by cooling, that is, the AI
If the temperature is not lowered to below the temperature at which -C11-MB type precipitates are generated, 417% will be released before baking, and therefore it is necessary to cool down to 550°C. Then, at the same time, the average crystal grain size is set to 25 μm or less, and at the same time, the component is maintained in a solid solution state that contributes to firing hardening.

The purpose of this cold rolling after cooling is to obtain the strength required as a candy material, and the cold rolling rate varies depending on the content of Cu, MB, and Mn, but an effect can be expected at less than 10%. First, hot rolling is carried out at a rolling strength of 10% or more.

The total rolling rate when hot rolling and 'cold rolling' is 99
The reason for this is that at the casting stage, the intermetallic compounds segregate to the grain boundaries and the total amount is large, and the occupancy of the intermetallic compounds seen from the surface of the final rolled plate is within a preferable range. In addition, in order to disperse as uniformly as possible, the total rolling ratio of hot rolling and cold rolling must be 99% or more.

Next(ko, lF'eu, 11% ten (Mnu+t%x1..
07)+(MHu+t%X0.27)=2.0~3.
0 is melted and then rapidly cooled and continuously formed to a thickness of 50+ nm or less when the value of the above formula is large, the casting thickness is large, and/or the total rolling ratio is small. In this case, the area occupation rate of the intermetallic compound becomes too large, which is undesirable.Furthermore, in order to reduce the thickness of # and + and increase productivity as a fill method, -
Within the range of 1 set, the casting thickness must be 50 tlIm or less and the cooling rate during solidification must be increased, and in the continuous casting method, the color value of 1 set must be 2.0 ~
Must be 3.0. When the cooling rate is high as described above, the products are small in size or relatively large in number, and exhibit a tendency to be uniformly dispersed.

Therefore, by setting the alloy rolling ratio of hot rolling and cold opening rolling to 90% or more, an appropriate A1 ratio can be achieved.

In addition, if necessary, the aluminum alloy strip after hot rolling after continuous casting is heat treated at a temperature of 300"C or higher. Edge cracking is likely to occur at the edges, so this is done to improve the rollability, and even if this is not the case, it is done to control the texture.

The area occupancy rate of the intermetallic compound explained above was determined by polishing the rolled surface of the rolled plate and observing it with an optical microscope at a magnification of 400 times.

Next, in Figures 1, 2, and 3, do(・II+1%+
(to'In u+t%X], 07) ten (Mεni1%X
0.27) The value of the formula (sometimes simply referred to as the formula), the maximum length of the intermetallic compound (μm), the area occupation rate of the intermetallic compound (%), the number of intermetallic compounds (1/3 (10 mm') :
), and Figure 51 shows the relationship between the lump thickness (lllIn) and the maximum length of the intermetallic compound (μTIT) when the value of the formula is 3.11. shows the relationship between the area occupation rate (%) of metal open compounds and the limit nide rate (%), and Figure 6 shows the relationship between the number of intermetallic compounds (1 /300
The figure shows the relationship between the 7-run moldability rate (%) and the 7-run moldability rate (%).

And, as is clear from these figures, the large S)
In the case of ingots (1QO+no+ or more), the value of the formula must be 3 or less, or 2.7 or less, and small ingots (continuous casting) α50m+n or less, in the figure In the case of 2), it is necessary to set the value of the formula to 2.0 to 3.0. Therefore, if the size of the intermetallic compound (crystallized product) is outside the range described in 1.
- Accommodation (0.5-5.0%), squeezeability, elongation, lungeability and ribbing) - low strength. Furthermore, it is within the range 11 [1 of the formula and Zn is contained i
From this, it is thought that the stiffness, elongation, run resistance, and bending properties of aluminum alloys will decrease as the strength of the aluminum alloy increases.
'1° is maintained and also improved.

. Next, examples of the aluminum lamination for forming, the alloy sheet strip, and the manufacturing method thereof according to the present invention will be described.

EXAMPLE An aluminum alloy having the ingredients and proportions shown in Table 1 was cast into 500 mm large ingots.The ingots were soaked at 570'C for 6 hours and hot rolled. It was rolled to a thickness of 3 mm from 1 mm, then cold rolled to I m III, and rolled at a heating rate of 500°C/min to 80 mm.
After heating to 500°C, the material was subjected to medium open dulling at a cooling rate of 500°C/min, and then cold rolled to a thickness of 0.4mm as a canvas body material and a thickness of 0.4mm as a can end material. The thickness was 3 mm. Comparative examples were No. 1, in which the Zn content was at the level of impurities, and No. 4, in which this No. 1 alloy was produced by a conventional method.

Table 2 shows the acid-resistant properties and average grain size.
, 1, No., and -1, it can be seen that it has a unique characteristic.

Table gjS3 shows the #AI inspection results for the 9 and r properties of can materials. The alloys No. 2, No. 3 according to the present invention are significantly superior, and furthermore, the elongation after t & [This related No.
.

It is clear that No. 2, No. 3, and No. 3 have improved.

Q) As explained in -, the aluminum alloy sheet strip for forming and the manufacturing method thereof according to the present invention has the structure described in -, so it has excellent ironing workability, flanging property, and reheating property. It has the effect of being suitable as a camping A-4 material.

[Brief explanation of the drawing]

Figures 1, 2, and 3 are Feu+L%+(Mnu+L
Figure 4 shows the relationship between the value of the formula %X1.07) + (M1%X0.27), the maximum length of the intermetallic compound, the area occupation rate of the intermetallic compound, and the number of intermetallic compounds. A diagram showing the relationship between the lump thickness and the maximum length of the intermetallic compound, and the fifth 1 is a diagram showing the relationship between the area occupation rate of the intermetallic compound and the limit work rate,
FIG. 6 is a diagram showing the relationship between the number of intermetallic compounds and the 7-run moldability rate. 1~Large Yu"clumps, 2~Small clumps. 1 spear included; Fe7” (n77 x 1.o7) size M, 7%XO, 2θ
(tw4%tsu22total-j Fdq(n44o7'l+(ny'ltrade27X'l) conflict 3 Goji 24 illustration) , Otsu Z left 6 figure

Claims (3)

[Claims] (1) Zn0.05-]u+t%, Fe 0.2~
0.7u+t%, CuO, 05-0.5+ut%,
MgO,5-2,5u+t%, Mn0.5-2,
Contains Ou+1%, Feu+1. % ten (jtrin
u+t%×], 07) 10(Mgu+I%X O,27
)≦3.0, the area occupation rate of the intermetallic compound on the surface of the rolled plate is 0.5 to 5%, and the size of each intermetallic compound is 45μ or less. , further characterized in that the average width of crystal grains across the surface of the rolled plate is 25 μm or less. (2) 7. nO,05-], u+t%, FeO
, 25-0.7u+t%, CuO, 05-0.5u+t
%, MB 0.5-2.5+ut%, MnO,! 5-2
, including Ou + 1%, Ga, Feu + 1% (M1] w
L%×1j17)+(l\4B needle%x O,27)≦
After melting A1 alloy which is 2.7] I' of 00nun or more
The ingot is soaked at 530°C or higher, and then rolled at 100°C/min to a temperature of 400 to 600°C with or without cold rolling after hot rolling. Immediately after heating, or after being held for less than 10 minutes, heat to 150°C at a cooling rate of OO'C/hour or more.
The average crystal diameter is reduced to 25μ or less, and the components contributing to hardening are kept in a solid solution state.
A method for producing a bake-hardened aluminum alloy hard strip, characterized by carrying out the above cold rolling so that the total rolling ratio of hot rolling and cold rolling is 99% or more. (3) 7. n O,05-1u+t%, Fe
0025-0.7wL%, CuO,05-0.5u
i%? v'1. B 0.5 □-2,5rJt%, M
n 0.5-2, including Ou+t%, Ga, To'011
11%+(ikin u+L%×1,.07)±(Mε
1%X O, 27) = 2.0-3.0 A
After melting the A1 alloy, continuous quenching is carried out to a thickness of 50 mtn or less, and the ingot is heat-treated at a temperature of 300°C, with or without hot rolling. with or without cold rolling, then with or without cold rolling, then at a temperature of 400-600°C for 10
Heating at a heating rate of 0°C/min or more, immediately after heating, or after holding for less than 10 minutes, cooling to 150°C or less at a cooling rate of 1.00'C/hour or more to determine the average grain size. 25μ
In addition to the following, it also contributes to baking hardening. - Maintaining the components in solid solution state, and further performing 10% cold rolling to bring the total rolling ratio of hot rolling and cold rolling to 90% or more. A method for producing hard plate strips of aluminum alloy by baking and hardening with J characteristics.