JPH0776411B2 - Method for manufacturing thin-walled high-strength blind aluminum material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing an aluminum material for blinds.

(Prior Art) Conventionally, as slats for blinds, 5052, 51
Al-Mg based aluminum alloys such as 54, 5182, 5086, 5083 are used.

The manufacturing method is cold rolling of hot rolled material with a high cold working rate to a thickness of 0.15 to 0.25 mm, then baking coating at 200 to 260 ° C, forming processing by roll forming and folding resistance. The slat material is cut into a predetermined length as a slat material for blinds. In addition, JP-A-1-205050
In the gazette, hot rolling, cold rolling, intermediate annealing (350 ° C x 4
hr), cold rolling at a high working rate to a thickness of 1.5 mm or more, stabilization treatment (120 ° C x 1 hr), and baking coating.

However, for blind materials, quality characteristics such as weight reduction, expansion of span width of slat material, and reduction of wall thickness have come to be required, and there have been the following problems.

(1) It is necessary to perform cold rolling at a high working rate to obtain high strength, and as a result, work hardening is remarkable due to plastic deformation, there is a limit to thinning, and a low strain plate with good dimensional accuracy is required. Hard to get. In addition, usually with a cold rolling mill
When rolling to a thickness of less than 0.15 mm, kissing rolls (contact phenomenon between upper and lower rolls) make rolling extremely difficult.

(2) In the case of high strength material obtained by this high processing rate,
With respect to its mechanical properties, its strength is remarkably reduced even in a short time heat treatment (heat treatment in baking coating) in a low temperature range (200 to 260 ° C.), and therefore it is difficult to maintain the strength after baking coating.

(3) In addition, since the thin blind material has a small heat capacity, variations in strength occur due to the effect of a slight temperature change during the baking coating, and the quality becomes unstable.

The present invention has been made in order to solve the above-mentioned problems of the prior art and to meet the above-mentioned demands.
Stable high strength can be obtained by baking treatment at a temperature of up to 260 ° C) for a short time, flatness can be maintained even after baking coating, moldability is not impaired, and thin, thick and easy manufacturing is possible. It is an object of the present invention to provide a method for manufacturing an aluminum material for blinds.

(Means for Solving the Problems) In order to solve the above problems, the present inventor considers that an extremely thin thickness such as less than 0.15 mm is desired as the plate thickness of the blind aluminum material, and thus the plate thickness 0.15 High processing rate of less than mm mm Diligent research on selection of component composition of aluminum alloy that can secure stable slat material quality for blinds by cold rolling and method to obtain bake hard effect only by heating for a short time by thin thickness As a result, the chemical composition adjustment and intermediate annealing conditions, the subsequent cold working rate,
By controlling the preheating conditions, especially 0.15
It has been found that, even in the case of an extremely thin cold rolled material having a thickness of less than mm, the strength after baking coating can be as high as or higher than that of the conventional material Al-Mg alloy, and the present invention is made here. is there.

That is, the present invention, Mn: 0.2 ~ 1.5%, Mg: 0.5 ~ 3.5%,
Cu: 0.2 to 0.5%, Si: 0.40% or less, Fe: 0.50% or less, the balance is aluminum alloy having a chemical composition consisting of aluminum and unavoidable impurities, heating during cold rolling performed after hot rolling A solution treatment of rapid heating and cooling at a temperature of 400 to 600 ° C is performed, and then cold rolling is performed at a working rate of 40% or more, the final plate thickness is less than 0.15 mm, and bake hard effect by baking coating after cold rolling. In order to give more effectively, the preheating at 100 to 200 ° C. is performed.

The present invention will be described in more detail below.

(Operation) First, the reason for limiting the chemical composition of the aluminum alloy in the present invention will be described.

Mn is added for the purpose of improving the strength, but if it is less than 0.2%, the effect of improving the strength is small, and if it exceeds 1.5%, the rolling property is deteriorated such as the occurrence of edge cracks and large crystallized substances are generated. Therefore, the Mn content is set to the range of 0.2 to 1.5%.

Mg requires 0.5% or more to obtain the bake hard effect, but if it exceeds 3.5%, the strength is greatly improved by cold working, and the thin wall thickness (less than 0.15 mm) can be obtained with high accuracy and production efficiency. It is difficult to raise and manufacture, and the strength during coating is greatly reduced, and the bake hard effect obtained by adding Cu described later is offset. Therefore, the amount of Mg is 0.5 ~
The range is 3.5%.

If Cu is less than 0.2%, the bake hard effect becomes extremely small, and the strength after coating does not reach the strength of the conventional Al-Mg alloy. However, if it is more than 0.5%, there may be a problem in the corrosion resistance of the punched portion of the blind slat material after coating, so the Cu content is made 0.2 to 0.5%.

The aluminum alloy in the present invention is Mn, Mg and Cu described above.
Is an essential component, but it is particularly preferable to regulate the Si content and Fe content as impurities. If Si exceeds 0.40%, the workability gradually decreases, so the content should be 0.40% or less. Also, Fe is 0.
If it exceeds 50%, workability and corrosion resistance gradually decrease, so the content is made 0.50% or less.

Next, manufacturing conditions will be described.

The above-mentioned aluminum alloy is made into a hot-rolled material by a conventional method, but the conditions such as cold-rolling performed after that must be the following conditions.

First, during cold rolling to a product sheet thickness, a solution treatment is performed in order to keep the components contributing to the bake hard effect in a solid solution state. For that purpose, the heating temperature is set to 400 to 600 ° C., and rapid heating and cooling are performed. If it is less than 400 ° C, the components contributing to the bake hard effect cannot be kept in a sufficiently solid solution state, and if it is higher than 600 ° C, blisters due to gas are generated on the plate surface,
This is not preferable because it may cause a local burning phenomenon. The heating rate is not particularly limited, but the cooling rate can maintain the solid solution state, for example, by cooling at a rate of 100 ° C./minute or more.

After the solution treatment, cold rolling with a working rate of 40% or more is performed. Although this cold rolling has a high working rate, the solution hardening temperature is high, so that work hardening is reduced, and it can be carried out without kiss roll with a high accuracy and a thin thickness, especially an extremely thin thickness. If the processing rate is less than 40%, desired high strength cannot be obtained.

After this cold rolling, preheating for heat treatment at 100 to 200 ° C. is performed. This is to reliably and stably bring out the bake hard effect in the baking process during baking coating. Therefore, this preheating is performed under the condition that no improvement in strength is observed in this process, rather, it can be said that it is a heat treatment for removing the strain caused by rolling and facilitating the subsequent strain correction. You can In addition,
The heating time is preferably 0.5 to 5 hours.

After the pre-heating, the slat material for blinds is straightened, slitted, etc. as in the conventional case.

(Examples) Examples of the present invention will be shown below.

Comparative Example First, with respect to the conventional Al-Mg alloy having the chemical composition shown in Table 1, 0.13 mm thick steel sheet and 0.1
A 15 mm thick plate was prototyped, and the degree of strength reduction due to softening under the current baking coating conditions when thinning (0.15 mm → 0.13 mm) was investigated. The results are shown in FIG. An oil bath was used to treat each temperature shown in the figure for 60 seconds to simulate baking coating conditions.

From FIG. 1, it can be seen that when the thickness is reduced to 0.13 mm, the strength is significantly reduced due to the reduction in thickness, especially in the high temperature range.

Therefore, conventional materials having the chemical components shown in Table 1 (Al-Mg
System, cold rolled material) and material of the present invention (Al-Mg-Mn-Cu system, cold rolled material)
About solution hardening characteristics by solution treatment (heating temperature 520 ° C) in CAL (continuous annealing furnace of high temperature and short time, rapid heating and cooling) and subsequent cold rolling (working ratio shown in Fig. 2) The softening characteristics by coating baking (heating in a salt bath for 30 seconds at the temperature shown in FIG. 3) were investigated.

As a result, regarding the work hardening characteristics, as shown in FIG. 2, the tensile strength and the yield strength of both the conventional material and the material of the present invention increase as the working rate increases, but the elongation decreases as the working rate increases. I understand.

As for the softening property, as shown in FIG. 3, the conventional material had a marked decrease in strength as the baking temperature increased.
Further, the material of the present invention also has a gradual decrease in strength, and the bake hard effect is small.

Example Material of the present invention having the chemical components shown in Table 1 (Al-Mg-Mn-
After performing solution treatment (heating temperature 520 ° C) in CAL (continuous annealing furnace of high temperature and short time, rapid heating and cooling) for Cu type and cold rolled material), cold rolling was performed at a working rate of 85%. Rolled plate (plate thickness
0.15 mm, 0.13 mm) was preheated at the temperatures shown in Table 2 and baked for coating (220 ° C. × 30 seconds oil bath) to examine the strength. Further, for comparison, an example in which the preheating treatment was not performed was also investigated. The results are shown in Table 2.

For the preheating treatment, three types of 120 ° C., 150 ° C. and 180 ° C. were selected and the holding time was 2 hours.

As can be seen from Table 2, by performing the preheating treatment within the scope of the present invention, an excellent bake hard effect is obtained. In particular, the optimum bake hard effect can be obtained by preheating to about 150 ° C.

Further, regarding the material of the present invention and the conventional material that have been preheated at 150 ° C. × 2 hr, both of the plate thickness of 0.15 mm and the ultrathin plate thickness of 0.13 mm, change in strength due to temperature change during baking coating (bake hard property )investigated. The results are shown in FIG.

As shown in FIG. 4, the conventional material 5083 is
It can be seen that the decrease in strength due to this heating and the change in strength due to the temperature difference are large, and this tendency is more pronounced when the sheet thickness is 0.13 mm.

On the other hand, the material of the present invention has a change in tensile strength and proof stress of 220 to 240 ° C.
It is extremely small in the baking temperature range and shows the same or higher level of strength as the conventional material, and it can be seen that the bake hard effect is remarkable when the ultrathin plate thickness is 0.13 mm.

(Effects of the Invention) As described in detail above, according to the present invention, the following excellent effects are obtained, so that it is possible to provide a high-quality thin-walled high-strength blind aluminum material at low cost.

(1) Since rolling and straightening are easy, it is possible to manufacture a blind material having a plate thickness of less than 0.15 mm, which was conventionally difficult to manufacture industrially.

Also, with the same plate thickness, the number of passes in the rolling process can be reduced by 20%.

(2) Since variations in strength due to temperature changes during baking coating are reduced, the formability of ultra-thin materials after baking coating is stable and the quality can be improved.

It is possible to improve the strength (especially yield strength) after baking coating as compared with conventional materials.

[Brief description of drawings]

Fig. 1 is a diagram showing the softening characteristics of 0.15 mm thick and 0.13 mm thick materials of the conventional material, Fig. 2 is a diagram showing the work hardening preparation of the conventional material and the material of the present invention, and Fig. 3 is the conventional material and the material Fig. 4 is a diagram showing softening characteristics of the invention material, and Figs. 4 (a) and 4 (b) are diagrams showing bake hard characteristics of the invention material and the conventional material after preheating, and Fig. 4 (a) is 0.15.
In the case of mm thickness, (b) shows the case of 0.13 mm thickness.

Claims (1)

[Claims] 1. (1) Mn: 0.2% by weight (hereinafter the same)
Aluminum alloy containing 1.5%, Mg: 0.5-3.5%, Cu: 0.2-0.5%, Si: 0.40% or less, Fe: 0.50% or less, the balance being aluminum and unavoidable impurities. Heating temperature during cold rolling performed after hot rolling
A solution heat treatment of rapid heating and cooling at 400-600 ℃ is performed, and then cold rolling is performed at a working rate of 40% or more, and the final plate thickness is 0.15 mm.
The method for producing an aluminum material for thin high-strength blinds is characterized by performing pre-heating at 100 to 200 ° C. in order to more effectively impart a bake hard effect by baking coating after cold rolling.