JP2017160521A - Manufacturing method of aluminum alloy sheet for beverage can body excellent in anisotropy and neck moldability and bottle can body excellent in anisotropy and bottle neck moldability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of an aluminum alloy sheet for a beverage can body excellent in anisotropy and neck moldability.SOLUTION: The invention include conducting a homogenization treatment on an ingot obtained by smelting an aluminum alloy containing, by mass%, Si, Fe, Cu, Mn, Mg of defined amounts and semi-continuously casing the same at 555 to 605°C for 4 to 10 hours, conducting a heat treatment at 500 to 555°C for 1 hour or longer, then conducting hot rough rolling at an outlet side temperature of 400 to 460°C, hot finishing rolling under a condition of at a first path outlet side temperature of 380°C or less, a second path outlet side temperature of 340°C or less and a third path outlet side temperature of 250 to 310°C and then conducting first cold rolling with rolling reduction rate of 10 to 20%, a first intermediate annealing under a condition of a retention temperature of 460 to 540°C and retention time of 5 to 60 sec. by using a continuous annealing device, and conducting a second cold rolling with rolling reduction rate of 80 to 95% to obtain an aluminum alloy sheet having sheet thickness of 0.210 to 0.47 mm and bearing force after galling of 230 to 320 N/mm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a beverage can body excellent in anisotropy and neck formability, and a method for producing an aluminum alloy plate for a bottle can body excellent in anisotropy and bottleneck formability.

Al-Mn-Mg based alloy hard plates such as JIS3004 (AA3004) or JIS3104 alloy are used for the can body of aluminum beverage cans. The alloy hard plate is required to have strength and corrosion resistance necessary for use as a container, a beautiful appearance, and excellent formability.
The said alloy hard plate is manufactured through processes, such as melting | dissolving, casting, homogenization, hot rolling, cold rolling, like a general aluminum alloy plate. In general, the balance of strength and formability of each part of the can body is tempered from 3/4 hard to special hard. That is, the aluminum alloy plate is recrystallized once in the course of rolling to be in a soft state, and then cold-rolled with a reduction rate of about 50 to 90% to obtain an appropriate strength mainly by work hardening.

When an aluminum alloy sheet is rolled using a recent industrial cold rolling mill, the material temperature becomes high due to heat generated by rolling, so that sufficient ductility can be obtained even with rolling. Therefore, the aluminum alloy sheet is usually used in a tempered condition (H16 to H19) as it is rolled. When sufficient ductility cannot be obtained, for example, when the rolling speed of the aluminum alloy plate is slow, it is conceivable that the aluminum alloy plate is used with H3X refining by performing stabilization annealing.
However, if the mechanical properties of the aluminum alloy rolled plate are anisotropic, the formability when forming the can body is hindered, the symmetry of the can body after forming is reduced, and the material usage yield is reduced. There are problems such as lowering. The anisotropy of the rolled sheet depends on the crystal grain orientation distribution (texture). Therefore, it is considered that the anisotropy of the rolled aluminum alloy sheet can be reduced by taking into account the change in texture due to cold rolling and controlling the texture that occurs during recrystallization before cold rolling.

From the above viewpoint, in order to control the anisotropy of the aluminum alloy rolled sheet, it is important how to control recrystallization before cold rolling. From this viewpoint, a method for producing an aluminum can body material Can be classified into the following three types.
(1) Hot rolling → Recrystallization → Final cold rolling In the first method, hot rolling is performed to a relatively thin aluminum alloy sheet of, for example, 3 mm or less, and after hot rolling, it is wound on a coil. This is a method in which recrystallization is performed as it is, or after artificial annealing and recrystallization, and then cold rolling.
(2) Hot rolling → low-pressure cold rolling → recrystallization → final cold rolling The second method is hot rolling to a relatively thin-walled aluminum alloy sheet of, for example, 3 mm or less, and then under a relatively low pressure. For example, as described in the following Patent Document 1, after performing cold rolling of 6 to 15% on an aluminum alloy sheet, annealing is performed, and finally the final cold rolling with a reduction rate of about 90% is performed. is there.
(3) Hot rolling → cold rolling → recrystallization using a continuous annealing furnace → final cold rolling at a relatively low pressure The third method is to perform first cold rolling after hot rolling of an aluminum alloy sheet. Thereafter, using a continuous annealing furnace, annealing is performed by rapid heating to a relatively high temperature, followed by rapid cooling, and finally cold rolling at a relatively low pressure reduction rate of, for example, about 60%.

Japanese Patent No. 3644819

By the way, the demand for lower prices for aluminum cans is severe, and therefore, attempts to reduce the amount of material used as much as possible continue. However, since it becomes difficult to balance formability and anisotropy when the material plate thickness is reduced, there is an increasing demand for a good balance between formability and anisotropy.
For example, to control the anisotropy of an aluminum alloy sheet, it is effective to use a tandem hot finish rolling mill. A single mill reverse hot finish rolling mill can obtain sufficient cubic orientation. However, it is difficult to control the anisotropy.

Further, when the method (1) described above is compared with the method (2), the method described in (2) is a process of cold rolling under a relatively low pressure compared to the method described in (1). However, this cold rolling process has the advantage that the development of the cube texture during annealing can be promoted.
As a result of repeated studies on the conditions for producing aluminum cans for beverages using a single mill reverse hot finish rolling mill, the present inventors can form a sufficient cubic orientation before cold rolling. The manufacturing method which can implement | achieve and control the anisotropy of the aluminum alloy plate for drink cans was discovered, and it reached this invention.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method for producing an aluminum alloy plate for a beverage can body having excellent anisotropy and neck formability.

The manufacturing method of the aluminum alloy plate for can bodies of this invention is mass%, Si: 0.35% or less, Fe: 0.35-0.55%, Cu: 0.15-0.48%, Mn: An ingot obtained by melting an aluminum alloy having a composition containing 0.8 to 1.15%, Mg: 0.60 to 1.60%, the balance being Al and inevitable impurities, and semi-continuously casting Hot rough rolling is performed through homogenization treatment and soaking treatment to obtain a hot rough rolled plate of 25 to 16 mm, and then the first pass first-side temperature is 380 ° C. or lower, and the second pass first-side temperature is 340 ° C. Hereinafter, after performing hot finish rolling with a third pass exit side finishing temperature of 250 to 310 ° C., first cold rolling with a reduction rate of 10 to 20% is performed, and then a continuous annealing apparatus is used. The first intermediate annealing is performed under the conditions of a holding temperature of 460 to 540 ° C. and a holding time of 5 to 60 seconds, There performing secondary cold rolling at a reduction rate of 80% to 95%, the thickness 0.210～0.47Mm, characterized in that to obtain an aluminum alloy plate strength 230~320N / mm ² after baking.

In the method for producing an aluminum alloy plate for a can body of the present invention, the homogenization treatment performed on the ingot is performed at 555 to 605 ° C. for 4 to 10 hours, and the subsequent soaking is performed at 500 to 555 ° C. It is preferable to carry out under the conditions of heating for 1 hour or longer.
In the method for producing an aluminum alloy plate for a can body according to the present invention, the material temperature on the final pass outlet side of the hot rough rolling is preferably 400 to 460 ° C.

In the method for producing an aluminum alloy plate for a can body according to the present invention, at least one of Cr: 0.05% or less, Zn: 0.25% or less, Ti: 0.10% or less is further added to the composition. Alternatively, an aluminum alloy containing two or more kinds can be used.
In the method for producing an aluminum alloy sheet for a can body according to the present invention, it is preferable that after the second cold rolling, final stabilization annealing is performed under conditions of a holding temperature of 120 to 140 ° C. and a holding time of 2 to 4 hours.

The method for producing an aluminum alloy plate for a can body according to the present invention is prepared by melting an aluminum alloy having a specific range of Si, Fe, Cu, Mn, and Mg, and specifying 1-3 passes after hot rough rolling. By performing hot finish rolling to control the outlet side temperature, subjecting to cold rolling with a reduction rate of 10 to 20%, subjecting to continuous annealing under specific conditions, and subjecting to final cold rolling with a reduction rate of 80 to 95%, It is possible to provide an aluminum alloy plate for a beverage can body and a bottle can body excellent in both anisotropy and neck formability.
In addition, by performing stabilized annealing with controlled holding temperature and holding time after the final cold rolling, it is possible to provide aluminum alloy plates for beverage can bodies and bottle can bodies that are further superior in anisotropy and neck formability. .

Explanatory drawing which shows the apparatus and process which are used in a hot rolling process, when implementing the manufacturing method which concerns on this invention. The schematic block diagram which shows an example of the continuous annealing apparatus used for implementation of the manufacturing method which concerns on this invention. Process drawing which shows an example of the manufacturing method of DI can. The fragmentary sectional view which shows an example of DI can.

Hereinafter, although each embodiment of the manufacturing method of the aluminum alloy plate for drink can bodies excellent in anisotropy and neck formability concerning the present invention is described, the present invention is not limited to the embodiment described below. Absent.
First, the composition of the aluminum alloy plate for can bodies used in the present embodiment will be described.
The aluminum alloy plate for a can body of the present embodiment is, by mass%, Si: 0.35% or less, Fe: 0.35 to 0.55%, Cu: 0.15 to 0.48%, Mn: 0.00. It is made of an aluminum alloy having a composition of Al containing 80 to 1.15%, Mg: 0.60 to 1.60% or less and the balance containing inevitable impurities. In addition, an aluminum alloy containing one or more of Cr: 0.05% or less, Zn: 0.25%, Ti: 0.10% or less is used for the aluminum alloy having the above composition ratio. May be.
Hereinafter, the reasons for limiting the composition of the aluminum alloy used in this embodiment will be described.
In addition, content of each element described in this specification is mass% unless otherwise specified, and includes an upper limit and a lower limit unless otherwise specified. For example, the notation of 0.35 to 0.55% means 0.35% or more and 0.55% or less.

"Si: 0.35% or less"
Si easily forms a compound with Mg contained at the same time, has a solid solution hardening action, a dispersion hardening action and a precipitation hardening action, and forms a compound with Al, Mn, Fe, etc., and seizes the die during molding. There is an effect to prevent. If the Si content exceeds 0.35% by mass, workability deteriorates, which is inconvenient.
"Fe: 0.35-0.55%"
Fe has the effect of preventing crystal fineness and seizure to a die during molding. If the Fe content is less than 0.35% by mass, the desired effect cannot be obtained, and if it exceeds 0.55% by mass, the workability deteriorates.

"Cu: 0.15-0.48%"
Cu easily forms a compound with Mg, and contributes to solid solution hardening, dispersion hardening, and precipitation hardening.
If the Cu content is less than 0.15% by mass, the desired effect cannot be obtained, and if it exceeds 0.48% by mass, the workability deteriorates.
“Mn: 0.8 to 1.15%”
Mn is easy to form a compound with Fe, Si, Al, etc., becomes a crystallization phase and a dispersed phase, exhibits a dispersion hardening action, and has an effect of preventing seizure to a die during molding. If the Mn content is less than 0.8% by mass, desired curing characteristics cannot be obtained, and if it exceeds 1.15% by mass, the workability deteriorates.
“Mg: 0.60 to 1.60%”
Mg has a solid solution strengthening action, enhances work hardening by rolling, and exhibits dispersion hardening and precipitation hardening action by coexisting with Si and Cu. If the Mg content is less than 0.60% by mass, the desired effect cannot be obtained, and if it exceeds 1.60% by mass, the workability deteriorates.

In the aluminum alloy used in the present embodiment, in addition to the main components of Si, Fe, Cu, Mn, and Mg, one or more of the following Cr, Zn, and Ti may be contained.
"Cr: 0.05% or less"
Cr exhibits the effect of preventing seizure on the die during crystal refinement and molding. If the Cr content exceeds 0.05% by mass, it becomes brittle and the workability deteriorates.

“Zn: 0.25% or less”
Zn has the effect of refining Mg, Si and Cu precipitates. If the Zn content exceeds 0.25% by mass, workability and corrosion resistance are deteriorated.
“Ti: 0.10% or less”
Ti has the effect of improving the workability by refining crystal grains. However, if the Ti content exceeds 0.10% by mass, a coarse compound is formed, and conversely, workability is deteriorated.

<Method for producing aluminum alloy plate for beverage can body having excellent anisotropy and neck formability>
Next, an embodiment of a method for producing an aluminum alloy plate for a beverage can body excellent in anisotropy and neck formability according to this embodiment will be described.
In the method for producing an aluminum alloy plate for a beverage can body of the present embodiment, the aluminum alloy having the above composition is melted and subjected to homogenization treatment and soaking treatment on the ingot obtained by casting. Hot rolling by rough rolling and subsequent hot finish rolling, first cold rolling with a low rolling reduction, first intermediate annealing, and final cold rolling to obtain a can having a desired thickness Obtain an aluminum alloy sheet for the body.
Furthermore, in addition to the above-mentioned steps, stabilization annealing can be performed under the conditions of a holding temperature of 120 to 140 ° C. and a holding time of 2 to 4 hours.
Hereinafter, the manufacturing method of the aluminum alloy plate for beverage can bodies excellent in anisotropy and neck formability of this embodiment will be described in the order of steps.

"casting"
After the aluminum alloy having the above composition is melted, an ingot is cast from the molten aluminum alloy according to a conventional method. When the aluminum alloy is melted prior to casting, inclusions such as hydrogen gas and oxide are removed, An ingot is obtained by a continuous casting method.
The solidification rate at this time is usually 5 to 20 ° C./second. The thickness of the cast ingot can be about 500 to 600 mm, for example.
Next, chamfering is performed, and the surface of the ingot is cut by about 1 to 25 mm to produce a chamfered body. The chamfering may be performed after a homogenization process described later.

"Homogenization treatment"
Next, a homogenization process is performed on the manufactured face cut body. The homogenization treatment is generally performed for homogenization of microsegregation generated by solidification of the molten metal, precipitation of supersaturated solid solution elements, transition of a metastable phase formed by solidification to an equilibrium phase, and the like.
In the homogenization treatment, it is important that the homogenization temperature is in the range of 555 to 605 ° C. If the homogenization temperature is less than 555 ° C., the effect of continuous annealing described later cannot be obtained, cracks are likely to occur in the hot rolling process and the first cold rolling process described later, and the ear rate of the final plate material is increased. Further, if the homogenization temperature exceeds 605 ° C, the ingot may be melted.

In the homogenization treatment, it is preferable to heat the face milling body to a homogenization temperature at a heating rate of 100 ° C./hour or less. If the heating rate exceeds 100 ° C./hour, melting may occur partially.
In the homogenization treatment, the time for maintaining the homogenization temperature (homogenization time) is preferably 4 hours or more and 10 hours or less. If the homogenization time is less than 4 hours, the homogenization may not proceed sufficiently. However, if the homogenization time is too long, there is no effect and the production efficiency is lowered. From the above viewpoint, the preferable homogenization time is in the range of 4 to 10 hours. Since the homogenization time is relatively long, this homogenization treatment is usually performed by placing it in a batch type furnace.
In this embodiment, after the homogenization treatment, the face cut body is further cooled to 500 to 555 [deg.] C., and after soaking for a predetermined time, hot rolling is started. The holding time (soaking time) in the temperature range of 500 to 555 ° C. can be performed for 1 hour or more.

"Hot rolling"
The hot rolling includes hot rough rolling and subsequent hot finish rolling. In the present embodiment, it is preferable to perform hot finish rolling using a single-mill reverse hot finish rolling mill.
In the hot rolling step, as shown in FIG. 1, after hot rough rolling to a thickness of about 20 mm using a hot roughing mill 20, a thickness of 2 to 7 mm using a hot finish rolling mill 30 is used. Hot rolled.

The hot roughing mill 20 shown in FIG. 1 includes, for example, upper and lower work rolls 21 and 22, backup rolls 23 and 24, and transport paths 4 and 6 in which a plurality of transport rollers are arranged, and has been transported aluminum. This is an apparatus for rolling an alloy plate 5 to a desired thickness by passing between work rolls 21 and 22.
In FIG. 1, the hot rough rolling mill 20 is a plate material by repeatedly supplying the aluminum alloy plate material 5 to the work rolls 21, 22 from the conveying paths 4, 6 on the left and right sides of the work rolls 21, 22 and sequentially rolling them. 5 can be rolled to a required thickness to obtain a plate 7.

  The hot finish rolling mill 30 shown in FIG. 1 is a single-mill reverse hot finish rolling mill, for example, upper and lower work rolls 31 and 32 and backup rolls 33 and 34 and installed on the entrance side of these rolls. A reel-type delivery winding device 35 and a reel-type delivery winding device 36 installed on the outlet side are provided. The hot finish rolling mill 30 is configured to wind a sheet material that is hot-rolled from the feed winder 35 and passed between the work rolls 31 and 32 by the feed winder 36, and from the feed winder 36. The operation of winding the sheet material hot-rolled by passing between the work rolls 31 and 32 again with the feed winder 35 is repeated as many times as necessary, and the interval between the work rolls 31 and 32 is gradually adjusted for each rolling operation. By doing so, it is an apparatus that hot-rolls an aluminum alloy plate material to a target plate thickness.

After the soaking process, the slab taken out from the soaking furnace usually starts hot rough rolling immediately, but if the slab temperature does not become less than 500 ° C., the start of hot rough rolling may be delayed. The number of hot rough rolling passes depends on the ingot (slab) thickness, finished thickness, slab width, alloy composition, and the like, but is generally in the range of tens of passes to tens of passes.
In the hot rough rolling, while the rolled material is thick, rolling is usually performed using a one-stand type rough rolling mill (hot rough rolling mill 20 shown in FIG. 1) in which a conveyance table is installed before and after the rolling mill. However, if the plate is thinned, the necessary transfer table length is increased, the slack due to the weight of the plate is increased, and the plate is likely to be cooled.

  Therefore, in order to hold on the transfer table, the plate thickness needs to be more than 10 mm. Therefore, the minimum plate thickness when the plate is sent from the roughing mill to the finishing mill depends on the coil weight and the plate width, but in the case of the weight and width used industrially, it is about 16 mm or more. preferable. Moreover, when the plate | board thickness at the time of sending to a finishing mill from a rough mill is too thick, the increase in the number of rolling passes in a finishing mill will be caused, and productivity will be reduced. Therefore, it is preferable that the upper limit of the sheet thickness at the time of sending to a finishing mill is 40 mm or less. When the aluminum alloy sheet is thinned from the above upper limit to the lower limit, hot finish rolling is performed with a single mill reverse hot finish rolling mill having the configuration shown in FIG.

Hot finish rolling is performed using a single-mill reverse hot finish rolling mill.
By using a single-mill reverse hot finish rolling mill (hot finish rolling mill 30 shown in FIG. 1) having a winding device on both sides of the rolling mill, the hot finish plate thickness can be reduced.
Therefore, since the reduction ratio of the subsequent cold rolling can be reduced, the number of cold rolling passes can be reduced and the productivity can be improved. On the other hand, for example, when a hot finish rolling mill in which the winding device is installed only on one side is used, there is a minimum value for the plate thickness that can be held on the transfer table, so that it can be rolled by hot rolling. The minimum plate thickness will increase. For this reason, the cold rolling reduction after hot rolling increases.

As described above, the reduction in the thickness of the finished sheet of hot rolling contributes to the improvement of productivity by reducing the number of cold rolling passes. Therefore, in this embodiment, it is preferable that the finishing plate | board thickness of hot finish rolling shall be in the range of 2-7 mm. If the finished sheet thickness is less than 2 mm, the reduction ratio of the first cold rolling is insufficient, and a low ear ratio cannot be obtained. If the finished plate thickness exceeds 7 mm, the number of passes of the first cold rolling increases and the productivity decreases.
As conditions for hot finish rolling, the outlet temperature of the first pass is set to 380 ° C. or lower, the outlet temperature of the second pass is set to 340 ° C. or lower, and the outlet temperature of the third pass (finishing temperature). Is preferably in the range of 250 to 310 ° C.
Moreover, it is preferable that the rolling reduction ratio in the third pass is 55% or more and 65% or less.

If the outlet temperature in the first pass is set to a temperature exceeding 380 ° C., the local strain during rolling becomes a driving force, the recrystallization partially proceeds, the mechanical properties deteriorate, and the random orientation is restored. There is a risk that the number of crystal grains increases and the anisotropy deteriorates.
If the outlet temperature in the second pass is set to a temperature exceeding 340 ° C., the same problem occurs due to the same phenomenon as in the first pass.
Regarding the outlet side temperature in the third pass, the same problem occurs due to the same phenomenon as in the first pass at a temperature exceeding 310 ° C. When the temperature is lower than 250 ° C., nuclei of recrystallized grains having a cube orientation are unlikely to be generated, and sufficient cube orientation does not grow even if the first intermediate annealing following the first cold rolling described later is performed, and the anisotropy deteriorates. .
In addition, if the rolling reduction ratio in the third pass is less than 55%, the same problem occurs due to the same phenomenon as in the case where the outlet temperature is less than 250 ° C. When it exceeds 65%, the rolling load becomes too large, and there arises a problem that it is difficult to perform stable rolling.

"First cold rolling"
In the first cold rolling step, the plate material cooled after the hot rolling is cold-rolled so as to be in the range of a reduction rate of 10 to 20%. 1st cold rolling is a process required in order to give the driving force for growing the nucleus of the cube orientation formed by hot rolling preferentially in the 1st intermediate annealing which follows. When the rolling reduction ratio of the first cold rolling exceeds 20%, the strain becomes excessive, and the growth of recrystallized grains with cubic orientation formed by hot rolling in the first intermediate annealing is hindered, and conversely the random orientation grows. To worsen anisotropy.
On the other hand, if the rolling reduction of the first cold rolling is less than 10%, it becomes difficult to control the rolling and the driving force for preferentially growing the cube orientation in the first intermediate annealing is insufficient. The directionality deteriorates.

"First intermediate annealing"
In the first intermediate annealing step, a holding temperature of 460 to 540 ° C. (range of 460 ° C. or more and 540 ° C. or less) is applied to the plate material after the first cold rolling using a continuous annealing apparatus having a basic configuration shown in FIG. ) For 5 to 60 seconds and then cooled.
In the first intermediate annealing step, heating is preferably performed at a heating rate in the range of 10 to 200 ° C./second (a range of 10 ° C./second or more and 200 ° C./second or less), and a cooling rate in the range of 10 to 200 ° C./second ( It is preferable to perform cooling at 10 ° C./second or more and 200 ° C./second or less).
This annealing step brings the aluminum alloy sheet material into a semi-softened state, and it is preferable to set the yield strength after annealing; YS (Yield Strength) within a suitable range.
If the annealing temperature is less than 460 ° C., the softening is insufficient, and sufficient cube-oriented grain growth cannot be obtained, resulting in deterioration of anisotropy. When the annealing temperature exceeds 540 ° C. or the holding time exceeds 60 seconds, the solid solubility of the solute element becomes excessive, the mechanical properties of the final product become high, and the neck formability of the can deteriorates.

  FIG. 2 shows an example of the basic configuration of a continuous annealing device (Continuous Annealing Line: CAL). The continuous annealing device 40 in this example draws a long aluminum alloy plate 42 from a supply roll 41 and cushions 43. Is supplied to a long furnace main body 44 of about several tens to 100 m through, and annealed under the above-mentioned conditions while moving in the furnace main body 44, and is drawn out from the furnace main body 44 after annealing, and is wound on a winding roll 47 through a shock absorber 46. It is a device that can be wound up. According to this continuous annealing apparatus 40, since the aluminum alloy plate material 42 passing through the furnace body 44 can be continuously processed alone, the annealing process can be performed under more accurate heating conditions and cooling conditions than the batch type annealing furnace. it can.

  And if it is the continuous annealing apparatus 40, even if the width | variety and diameter of the coil of the state which wound the aluminum alloy board | plate material 42 around the supply roll 41 differ, in other words, the width | variety and thickness of the aluminum alloy board | plate material 42, and the length which should be processed Even if the lengths are different, annealing can be performed in the order in which they are to be manufactured.Therefore, the intermediate stock is increased compared to the case of the batch type annealing furnace in which only coils of the same size are brought into the annealing furnace and annealed. Can be suppressed.

"Second cold rolling"
Next, cold rolling is performed on the plate material after the first intermediate annealing so that the rolling reduction is within a range of 80 to 95%. By setting the rolling reduction ratio of the second cold rolling within the range of 80 to 95%, it is possible to achieve both appropriate mechanical properties required for a can body plate material and anisotropy and neck formability.
If the reduction ratio of the second cold rolling is less than 80%, the processing rate is insufficient and the required strength cannot be obtained, and the problem is that work hardening tends to occur and the neck formability of the can is lowered.
When the reduction ratio of the second cold rolling exceeds 95%, the processing rate becomes excessive, and in some cases, the strength becomes excessive, and the anisotropy deteriorates.
By the second cold rolling, an aluminum alloy plate for beverage can bodies having a plate thickness of 0.210 to 0.47 mm can be obtained. Moreover, it is preferable that this aluminum alloy plate has the yield strength after baking by coating in the range of 230 to 320 N / mm ² .

"Stabilized annealing"
According to the above production method, an aluminum alloy plate for a can body having excellent anisotropy and neck formability can be obtained. In DI molding of the alloy plate, depending on the shape and molding conditions of the bottom of the can, the bottom There may be a problem of molding abnormality such as missing.
For this reason, local formability such as can bottom molding can be improved by performing stabilization annealing on the alloy plate under the conditions of a holding temperature of 120 to 140 ° C. and a holding time of 2 hours to 6 hours. Can be effectively suppressed.

If the holding temperature is less than 120 ° C., there is a problem in that the above effect is hardly recognized. If the holding temperature exceeds 140 ° C., the problem of strength reduction occurs.
If the holding time is less than 2 hours, it is difficult to stably heat the entire coil, which is not preferable. If the holding time is longer than 4 hours, productivity is lowered.
By performing the stabilization annealing treatment under the above-described conditions, there is a feature that molding can be performed without causing abnormalities in can molding and problems of stable productivity.

Below, the outline | summary of the process and DI can which manufacture a DI can using the above-mentioned aluminum alloy plate are demonstrated.
FIG. 3 is a process diagram of a method for manufacturing a DI can, and FIG. 4 is a partial cross-sectional view showing the DI can. In these drawings, reference numeral 10 indicates the DI can.
The DI can 10 is a bottomed cylindrical DI can made of an aluminum alloy, and an iron alloy plate material having a thickness of 0.240 mm or more and 0.270 mm or less has an ironing rate of 54.2% or more and 64. For example, the size in the can axis direction, that is, the height is about 122.5 mm, and the outer diameter is 65 mm or more and 67 mm or less. The body portion has a wall thickness of 0.095 mm to 0.110 mm, a tensile strength of 340 MPa to 410 MPa, and a can body weight of 11.6 g or less.

Further, as shown in FIG. 4, the bottom portion 12 includes a dome portion 12 a that is recessed inward in the can axis direction of the trunk portion 11, and an outer peripheral edge portion of the dome portion 12 a is in the can axis direction of the trunk portion 11. It is set as the annular convex part 12c which protrudes toward the outer side. The top of the annular convex portion 12c in the can axis direction is a grounding portion 12b that contacts the grounding surface L when the DI can 10 is placed on the grounding surface L so that the DI can 10 is in an upright posture. .
In addition, the DI can 10 is made by printing and painting the outer surface of the body portion 11 including a printed portion such as character information using a polyester-based paint, and the DI can 10 subjected to the outer surface printing and the outer surface coating is 180 ° C. After forming a 50 mg / dm ² coating film by heating for 30 seconds, the inner surface of the DI can 10 was coated with an epoxy-based paint and heated to 200 ° C. for 60 seconds to be 40 mg / dm ² The outer surface printing, the outer surface coating, and the inner surface coating in which the above coating film is formed are performed.

This DI can is manufactured by the following processes, for example.
A disk-shaped plate material (blank) W having a diameter of about 150 mm is formed by punching the aluminum alloy plate obtained in the above-described process.
Next, the plate material W is drawn into a cup-shaped body W1 by drawing with a cupping press.
Subsequently, the DI processing apparatus performs redrawing and ironing on the cup-shaped body W1 to form a bottomed cylindrical body W2. In this case, the ironing rate is, for example, 60.4%, and the ironing process is performed until the thickness of the thinnest portion of the body portion 11 becomes 0.100 mm.

  The DI processing apparatus used for the redrawing ironing process includes a single redrawing die having a circular through hole for redrawing processing, and a plurality of sheets having circular through holes arranged coaxially with the redrawing die ( For example, three ironing dies (ironing dies) are coaxial with the ironing die, and can be fitted into the through holes of the respective ironing dies, and are movable in the axial direction. A cylindrical punch sleeve and a cylindrical cup holder sleeve fitted to the outside of the punch sleeve are provided.

  In the redrawing process by the DI processing apparatus, the cup W1 is disposed between the punch sleeve and the redrawing die, the cup holder sleeve and the punch sleeve are advanced, and the cup holder sleeve is moved to the end face of the redrawing die. The punch sleeve pushes the cup W1 into the through-hole of the redraw die while pressing the bottom surface to perform the cup pressing operation. As a result, a redrawn cup having a predetermined inner diameter is formed. Subsequently, the redrawn cup is passed through a plurality of ironing dies one after another and gradually ironed, and the side wall of the cup-shaped body is squeezed to extend the side wall to increase the side wall height and wall thickness. To form a bottomed cylindrical body W2.

The bottomed cylindrical body W <b> 2 that has been subjected to the ironing process has its bottom formed, for example, in a dome shape by the punch sleeve further pushing forward and pressing the bottom against the bottom molding die.
The bottomed cylindrical body W2 is cold-worked and hardened by the side walls being squeezed to increase the strength.

Next, the open end W2a of the bottomed cylindrical body W2 is trimmed.
Since the opening end W2a of the bottomed cylindrical body W2 formed by the DI processing apparatus is uneven and has a concavo-convex shape that undulates in the can axis direction, the opening end W2a of the bottomed cylindrical body W2 is By cutting and trimming, the height of the side wall in the can axis direction is made uniform over the entire circumference.
In this way, the DI can 10 having a circular cross section having the body 11 and the bottom 12 can be formed.

  If it is the aluminum alloy plate obtained by the above-mentioned manufacturing method, even when it is subjected to ironing in the above-mentioned DI can manufacturing method, it can be made excellent in neck formability, such as scratches and molding defects. An aluminum can that does not cause problems can be obtained.

EXAMPLES Hereinafter, although an Example is shown and the manufacturing method of the aluminum alloy plate for can bodies which concerns on this invention is demonstrated in detail, this invention is not limited to a following example.
Aluminum alloys having the compositions shown in Tables 1 and 2 were melted, degassed and filtered with molten metal, and then cast into a slab having a thickness of 600 mm, a width of 1100 mm, and a length of 4.5 m by semi-continuous casting. In addition, the Cr, Zn, and Ti contents in each slab of this example are substantially the same, Cr = 0.02 to 0.03%, Zn = 0.15 to 0.17%, Ti = 0.02 to 0, respectively. 0.03%.

Next, after chamfering the slab, using a homogenization / soaking furnace, a homogenization treatment with a holding temperature of 565 ° C. and a holding time of 8 hours, and then cooled in the furnace to a holding temperature of 545 ° C., Soaking was performed at the holding temperature for a holding time of 1 hour or longer.
Subsequently, after hot rough rolling to a plate thickness of 20 mm using the hot rough rolling machine 20 having the configuration shown in FIG. 1, using a single-mill reverse hot finish rolling mill 30 shown in FIG. Plates with various finished plate thicknesses were obtained by hot finish rolling.
As shown in Tables 1 and 2, the outlet temperature of the hot rough rolling was set to 430 ° C.
As shown in Tables 1 and 2, the delivery temperature in the first pass of hot finish rolling is adjusted to 375 to 385 ° C., and the delivery temperature in the second pass is adjusted to 330 to 345 ° C. The outlet temperature of the eyes was adjusted to 225 to 315 ° C.

Next, after the first cold rolling is performed on the plate material after the hot rolling at the rolling reduction (first cold rolling rate) shown in Tables 3 and 4, the results shown in Tables 3 and 4 are used using a continuous annealing apparatus. The first intermediate annealing (CAL) under the conditions of an average heating rate of 25 ° C./second from the normal temperature to the holding temperature, a holding time of 5 to 60 seconds, and an average cooling rate of 50 ° C./second from the highest temperature to 70 ° C. at the holding temperature. )
Next, the plate material after the first intermediate annealing is subjected to the second cold rolling at the rolling reduction (second cold rolling rate) shown in Tables 3 and 4, and the can body having the plate thickness (mm) shown in Tables 3 and 4 An aluminum alloy plate was obtained.
In addition, a part of the obtained aluminum alloy plate for can bodies was further subjected to stabilization annealing under the conditions of 3 hours for 3 hours held at the holding temperatures shown in Tables 3 and 4 using a batch annealing furnace. It was.

The material strength (ASTS) of the obtained aluminum alloy plate for can bodies was determined by a tensile test according to JISZ2241, and further subjected to heat treatment equivalent to paint baking under conditions of 210 ° C. × 10 minutes, and the yield strength after baking (ABYS, 0 .2% yield strength) was measured.
The physical property values (ASTS) were measured for samples taken from three or more positions in the width direction and longitudinal direction of the coil, and the ASTS variation (maximum value-minimum value) was within an allowable range of less than 8 MPa. .
About the obtained blank material of the aluminum alloy plate for can bodies, it processed into the drink can of capacity | capacitance 350cc.

`` Ear rate ''
As anisotropy evaluation of the obtained aluminum alloy plate for can bodies, the ear rate in cup molding was measured.
The ear rate was calculated from the height of the side wall of the cup that was deep-drawn from the Eriksen testing machine. The processing conditions were punch diameter: 33 mm (flat head punch), drawing ratio: 1.75, wrinkle holding force: 3 kN. The side wall height of this cup was measured with a digital micrometer, and the ear rate was calculated by the following formula.
(Mountain average height-average valley height) ÷ average valley height x 100 = ear rate (%)
The average height of the 0 ° and 180 ° peaks and the average height of the 45 °, 135 °, 225 °, and 315 ° peaks were determined, and the higher one was defined as the average height of the above equation. In addition, the average valley heights of 90 ° and 270 ° were obtained and used as the average valley height of the above formula.
As an evaluation of anisotropy by the ear ratio, the average value of n = 3 is less than 1.5% “「 ”, 1.5% or more and less than 2.5%“ ◯ ”, 2.5% or more. Less than 5% was designated as “Δ”, and 3.5% or more was designated as “x”. “◎” and “○” were judged to be acceptable levels.

The neck formability was evaluated by molding all samples into 350 cc beverage cans. After the DI molding, the mouth end of the can was removed by trim, washed and dried, and coated and printed on the inner and outer surfaces of the can, followed by die neck molding and spin flow molding to form a neck shape of a 350 cc beverage can having an inner diameter of approximately 55 mm. In addition, the crack produced from the curl part in a neck shaping | molding process to a screw part was accelerated and evaluated by making thin the thickness of the site | part which receives neck shaping | molding process in DI shaping | molding. 24 cans of each sample were manufactured, and the number of cans in which cracks occurred from the curled portion to the screw portion was visually counted to obtain a neck forming defect rate. A case where no neck molding failure was observed was marked as ◎, a case where the neck molding failure rate was 5% or less was marked as ◯, a case where the neck molding failure rate was 5% to 10%, and a value exceeding 10%. The case of ◎ or ○ was determined to be acceptable, and Δ or × was determined to be unacceptable.
The above results are shown in Tables 1 to 4 below.

As shown in Tables 1 and 3, the sample samples of Nos. 1 to 16 are respectively desirable alloy components, first pass to third pass exit temperatures, first cold rolling reduction, and first intermediate annealing conditions. Since the second cold rolling reduction ratio was satisfied, the aluminum alloy plate was excellent in BS yield strength, free of anisotropy, and excellent in neck formability.
In contrast to these example samples, the comparative example sample of No. 17 is a sample in which the exit side temperature of the hot finish rolling first pass is set to 385 ° C. higher than the desired range of 380 ° C. or lower. It deteriorated and caused problems in neck formability.
The comparative sample of No. 18 is a sample in which the exit temperature of the second hot finish rolling pass is set to 345 ° C. higher than the desired range of 340 ° C. or lower, but the anisotropy deteriorates and the neck formability is also reduced. Caused a problem.
The comparative sample of No. 19 was a sample in which the outlet temperature of the third hot finish rolling pass was set to 315 ° C. higher than the desired range of 310 ° C. or less, but both anisotropy and neck formability deteriorated.

The comparative sample of No. 20 is a sample in which the exit temperature of the third hot finish rolling pass is set to 225 ° C. which is lower than the desired range of 250 ° C. or more, but the anisotropy deteriorates and the neck formability is also reduced. Caused a problem.
The comparative sample of No. 21 is a sample in which the reduction ratio of the first cold rolling is set to 8%, which is lower than 10% or more of the desired range, but the anisotropy is deteriorated and the neck formability is also problematic. It was.
The comparative sample of No. 22 was a sample in which the reduction ratio of the first cold rolling was set to 22% higher than 20% or less of the desired range, but both the anisotropy and neck formability deteriorated.
The comparative sample of No. 23 was a sample that was not subjected to the first intermediate annealing treatment, but both anisotropy and neck formability deteriorated.
The comparative sample of No. 24 was a sample in which the temperature of the first intermediate annealing process was made too low, but both the anisotropy and neck formability deteriorated.
The comparative sample of No. 25 was a sample in which the temperature of the first intermediate annealing treatment was increased too much, but the neck formability deteriorated although the anisotropy was good.

The comparative sample of No. 26 was a sample in which the Si content was excessive in the aluminum alloy components, but the anisotropy was good, but the neck formability deteriorated.
The comparative sample of No. 27 is a sample in which the Fe content is excessively reduced in the components of the aluminum alloy, and the comparative sample of No. 28 is a sample in which the Fe content is excessively increased, but the anisotropy is good. However, the neck formability deteriorated, and when the Fe content was small, the die was seized.
The comparative sample of No. 29 is a sample in which the Cu content is excessively reduced in the components of the aluminum alloy, and the comparative sample of No. 30 is a sample in which the Cu content is excessively increased. Yield strength decreased, anisotropy deteriorated, and neck formability deteriorated when Cu was excessive.
The comparative sample of No. 31 is a sample in which the Mn content is excessively reduced in the components of the aluminum alloy, and the comparative sample of No. 32 is a sample in which the Mn content is excessively increased. Both the directivity and neck formability deteriorated, and seizure occurred, and when Mn was excessive, anisotropy deteriorated and neck formability deteriorated.
The comparative sample of No. 33 is a sample in which the Mg content is excessively reduced in the components of the aluminum alloy, and the comparative sample of No. 34 is a sample in which the Mg content is excessively increased. Both anisotropy and neck formability deteriorated. When Mg was excessive, anisotropy deteriorated and neck formability deteriorated.
The comparative sample of No. 35 was a sample in which the stabilization annealing temperature was excessively high, but the anisotropy and neck formability were good, but the BS proof stress was lowered.

  DESCRIPTION OF SYMBOLS 1 ... Blank material, 2 ... Cup, 3 ... Can body, 3A ... Ear | edge, 4, 6 ... Conveyance path 5, 7 ... Plate material, 10 ... Bottle-type drink can, 11 ... Body part, 12 ... Shoulder part, 13 ... Neck, 14 ... Screw, 15 ... Curl, 16 ... Bottom, 20 ... Hot roughing mill, 21, 22 ... Work roll, 23, 24 ... Backup roll, 30 ... Hot finish rolling mill, 31, 32 ... Work rolls, 33, 34 ... Backup rolls, 35, 36 ... Sending and winding device, 40 ... Continuous annealing device, 41 ... Supply roll, 42 ... Aluminum alloy sheet, 43, 46 ... Shock absorber, 44 ... Furnace body, 47 ... take-up roll.

In the redrawing process by the DI processing apparatus, the cup- shaped body W1 is disposed between the punch sleeve and the redrawing die, the cup holder sleeve and the punch sleeve are advanced, and the cup holder sleeve is cupped on the end face of the redrawing die. The punch sleeve presses the cup- shaped body W1 into the through-hole of the redraw die while pressing the bottom surface of the shaped body W1 to perform the cup pressing operation. As a result, a redrawn cup having a predetermined inner diameter is formed. Subsequently, the redrawn cup is passed through a plurality of ironing dies one after another and gradually ironed, and the side wall of the cup-shaped body is squeezed to extend the side wall to increase the side wall height and wall thickness. To form a bottomed cylindrical body W2.

The neck formability was evaluated by molding all samples into 350 cc beverage cans. After the DI molding, the mouth end of the can was removed by trim, washed and dried, and coated and printed on the inner and outer surfaces of the can, followed by die neck molding and spin flow molding to form a neck shape of a 350 cc beverage can having an inner diameter of approximately 55 mm. Note that when the DI forming, by reducing the thickness of the portion receiving the neck molding promoted evaluated cracks occurring in portions to form a curled portion and a threaded portion have your neck molding. 24 cans of each sample were manufactured, and the number of cans in which a crack occurred in the curled portion and the portion corresponding to the formation of the screw portion was visually counted to obtain a neck forming defect rate. A case where no neck molding failure was observed was marked as ◎, a case where the neck molding failure rate was 5% or less was marked as ◯, a case where the neck molding failure rate was 5% to 10%, and a value exceeding 10%. The case of ◎ or ○ was determined to be acceptable, and Δ or × was determined to be unacceptable.
The above results are shown in Tables 1 to 4 below.

As shown in Tables 1 and 3, the sample samples of Nos. 1 to 16 are respectively desirable alloy components, first pass to third pass exit temperatures, first cold rolling reduction, and first intermediate annealing conditions. Since the second cold rolling reduction ratio is satisfied, the aluminum alloy sheet has excellent AB yield strength, no anisotropy, and excellent neck formability.
In contrast to these example samples, the comparative example sample of No. 17 is a sample in which the exit side temperature of the hot finish rolling first pass is set to 385 ° C. higher than the desired range of 380 ° C. or lower. It deteriorated and caused problems in neck formability.
The comparative sample of No. 18 is a sample in which the exit temperature of the second hot finish rolling pass is set to 345 ° C. higher than the desired range of 340 ° C. or lower, but the anisotropy deteriorates and the neck formability is also reduced. Caused a problem.
The comparative sample of No. 19 was a sample in which the outlet temperature of the third hot finish rolling pass was set to 315 ° C. higher than the desired range of 310 ° C. or less, but both anisotropy and neck formability deteriorated.

The comparative sample of No. 26 was a sample in which the Si content was excessive in the aluminum alloy components, but the anisotropy was good, but the neck formability deteriorated.
The comparative sample of No. 27 is a sample in which the Fe content is excessively reduced in the components of the aluminum alloy, and the comparative sample of No. 28 is a sample in which the Fe content is excessively increased, but the anisotropy is good. However, the neck formability deteriorated, and when the Fe content was small, the die was seized.
Sample Comparative Sample of No.29 is that too small a Cu content in the components of the aluminum alloy, although Comparative Sample of No.30 is a sample too much Cu content, AB in the case of Cu under- Yield strength decreased, anisotropy deteriorated, and neck formability deteriorated when Cu was excessive.
The comparative sample of No. 31 is a sample in which the Mn content is excessively reduced in the components of the aluminum alloy, and the comparative sample of No. 32 is a sample in which the Mn content is excessively increased. Both the directivity and neck formability deteriorated, and seizure occurred, and when Mn was excessive, anisotropy deteriorated and neck formability deteriorated.
The comparative sample of No. 33 is a sample in which the Mg content is excessively reduced in the components of the aluminum alloy, and the comparative sample of No. 34 is a sample in which the Mg content is excessively increased. Both anisotropy and neck formability deteriorated. When Mg was excessive, anisotropy deteriorated and neck formability deteriorated.
The comparative sample of No. 35 was a sample in which the temperature of the stabilization annealing was increased too much, but the anisotropy and neck formability were good, but the AB yield strength decreased.

4, 6 ... conveying path, 5, 7 ... plate material, 10 ... DI can, 11 ... trunk, 12 ... bottom part , 12a ... dome part, 12b ... grounding part, 12c ... annular convex part, 13 ... neck part, 14 ... Flange part (curl part and screw part forming equivalent part), 20 ... hot rough rolling mill, 21, 22 ... work roll, 23, 24 ... backup roll, 30 ... hot finish rolling mill, 31, 32 ... work roll , 33, 34 ... backup roll, 35, 36 ... delivery winding device, 40 ... continuous annealing device, 41 ... supply roll, 42 ... aluminum alloy sheet, 43, 46 ... shock absorber, 44 ... furnace body, 47 ... winding Roll , W ... plate material, W1 ... cup-shaped body, W2 ... bottomed cylindrical body, W2a ... open end .

Claims (5)

In mass%, Si: 0.35% or less, Fe: 0.35-0.55%, Cu: 0.15-0.48%, Mn: 0.8-1.15%, Mg: 0.60 An ingot obtained by melting an aluminum alloy containing ˜1.60% and the balance consisting of Al and inevitable impurities and semi-continuously casting is subjected to hot rough rolling through homogenization treatment and soaking treatment Then, the first pass first-side temperature is 380 ° C. or lower, the second pass first-side temperature is 340 ° C. or lower, and the third pass third-side finish temperature is 250 to 310 ° C. After the hot finish rolling, the first cold rolling with a reduction rate of 10 to 20% is performed, and then the holding temperature is 460 to 540 ° C. and the holding time is 5 to 60 seconds using a continuous annealing apparatus. The first intermediate annealing is performed under the following conditions, followed by the second cold rolling at a rolling reduction of 80 to 95%, 0.210～0.47Mm, anisotropic and neck molding excellent in beverage can bodies for aluminum alloy sheet, characterized in that to obtain an aluminum alloy plate strength 230~320N / mm ² after baking, and anisotropically For producing aluminum alloy sheet for bottle can body with excellent moldability and bottleneck formability.   The homogenization treatment performed on the ingot is performed at 555 to 605 ° C. for 4 to 10 hours, and the subsequent soaking is performed at 500 to 555 ° C. for 1 hour or more. The manufacturing method of the aluminum alloy plate for drink can bodies excellent in anisotropy and neck moldability of Claim 1, and the aluminum alloy plate for bottle can bodies excellent in anisotropy and bottle neck moldability.   3. The aluminum alloy for beverage can bodies having excellent anisotropy and neck formability according to claim 1, wherein the material temperature on the final pass outlet side of the hot rough rolling is 400 to 460 ° C. 3. A method for producing an aluminum alloy plate for a bottle can body having excellent anisotropy and bottleneck formability.   In addition to the above composition, an aluminum alloy containing at least one or more of Cr: 0.05% or less, Zn: 0.25% or less, Ti: 0.10% or less is used. The aluminum alloy plate for beverage can bodies excellent in anisotropy and neck formability according to any one of claims 1 to 3, and a bottle excellent in anisotropy and bottleneck formability Manufacturing method of aluminum alloy plate for can body.   After the second cold rolling, the final stabilization annealing is performed under the conditions of a holding temperature of 120 to 140 ° C and a holding time of 2 to 4 hours. 5. The difference according to any one of claims 1 to 4, An aluminum alloy plate for beverage can bodies excellent in isotropic and neck formability, and a method for producing an aluminum alloy plate for bottle can bodies excellent in anisotropy and bottleneck formability.

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