JP6478073B2 - Magnesium alloy coil material - Google Patents

Description

  The present invention relates to a magnesium alloy coil material suitable for a material of a magnesium alloy member subjected to plastic working such as press working, and a method for manufacturing the same. In particular, the present invention relates to a magnesium alloy coil material having excellent surface properties and a method for producing the same.

  Magnesium alloys that are lightweight and excellent in specific strength and specific rigidity have been used as constituent materials for casings of portable electric and electronic devices such as mobile phones and notebook personal computers, and various members such as automobile parts.

  Since the crystal structure of the magnesium alloy is dense hexagonal, the slip surface at a low temperature such as room temperature is only the bottom surface. Therefore, when performing various plastic processing such as rolling and pressing on a magnesium alloy, it is generally performed in a state heated to a temperature of 200 ° C. or higher (typically warm). In particular, alloy types having a high Al content (for example, AZ91 alloy in ASTM standard) are inferior in plastic workability compared to alloy types having a low Al content (for example, AZ31 alloy and AZ61 alloy in ASTM standard). When performing plastic working such as rolling or pressing, the material is heated. Patent Document 1 discloses that a magnesium alloy sheet excellent in press workability can be obtained by performing rolling by performing specific temperature control on a material made of an AZ91 alloy in the ASTM standard.

  On the other hand, in the case of cold-workable steel, copper and alloys thereof, aluminum and alloys thereof, when cold rolling is performed, a large amount of lubricant (rolling oil) is used to improve lubricity, and after rolling, surplus Minutes are removed (see, for example, Patent Document 2).

JP 2011-131274 A JP 2000-263123 A

  When manufacturing a magnesium alloy member (plastic working member) by performing plastic working such as press working, if a continuous long plate or a wide plate having a wider width is used as a material, the length becomes a predetermined length. Compared to the case of using a cut sheet plate, it is expected that the yield can be improved and the productivity can be increased. Therefore, a magnesium alloy coil material obtained by winding a long rolled plate or a wider rolled plate can be said to be a suitable material for mass production of magnesium alloy members.

  In using the magnesium alloy coil material as a material for a plastic working member, a material having excellent surface properties is desired.

  As described in Patent Document 1, a magnesium alloy coil material having excellent surface properties such as having a metallic luster is obtained by polishing a rolled plate. Further, the polishing amount enough to give a metallic luster is at most about 100 μm in total on the front and back sides of the rolled plate, and is usually 30 μm or less from the viewpoint of material yield. Since the polishing amount is small and light polishing, a rolled plate having a thickness that allows for this polishing amount is manufactured.

  However, when large wrinkles (dents) occur during rolling, particularly when deep wrinkles occur, it is necessary to increase the amount of polishing in order to eliminate such wrinkles. As a result, the amount of material discarded increases and the polishing time becomes longer, leading to a decrease in productivity. In addition, if only the ridges are polished, the thickness in the longitudinal direction and the width direction of the rolled plate constituting the coil material varies, and therefore the amount of polishing is large over the entire length and the entire width of the rolled plate constituting the coil material. It is necessary to polish. Then, a healthy part without wrinkles will be polished in a large amount, resulting in poor yield and reduced productivity. Further, when there is a flaw that is difficult to remove by polishing, the portion of the flaw must be cut and removed, and a long magnesium alloy coil material cannot be obtained.

  From the above, after rolling, there is only a wrinkle that can be removed by light polishing with a small amount of polishing, preferably a magnesium alloy coil material having no wrinkles, and a method for producing such a magnesium alloy coil material having excellent surface properties. Development is desired.

  Therefore, one of the objects of the present invention is to provide a magnesium alloy coil material having excellent surface properties. Another object of the present invention is to provide a method for producing a magnesium alloy coil material capable of producing a magnesium alloy coil material having excellent surface properties.

  In a magnesium alloy, particularly a magnesium alloy containing more than 7.2% by mass of Al and containing a large amount of Al, the edge of the rolled plate is more likely to break during rolling than the center (see Patent Document 1). And it is easy to generate | occur | produce the waste (henceforth a rolling waste) which fell out from the rolling plate main body by the crack of this edge part. As described in Patent Document 1, by performing a specific temperature adjustment, although the above-described edge cracks can be reduced to some extent, rolling scraps may be generated. And this rolling waste may adhere to the surface of a rolling plate. Here, also when rolling a magnesium alloy, rollability can be improved by using a lubricant (see Patent Document 1). Therefore, in rolling a magnesium alloy, an amount of lubricant that does not decrease the temperature of the material (a small amount compared to a metal that is cold-rolled) may be used. In this case, it is considered that the lubricant remains on the rolled plate, so that the above-mentioned rolling scraps are easily attached and are not easily detached from the surface of the rolled plate.

  On the other hand, when a coil material is manufactured by winding a sheet material rolled by a rolling roll with a reel, a roll that performs various actions on the rolled sheet (hereinafter referred to as a work roll) is closer to the reel side than the rolling roll. May be placed. The work roll is used in contact with a plate material (rolled plate) that has passed through the roll (details will be described later). As a result of investigations by the present inventors, these work rolls come into contact with the rolling plate to which the above-mentioned rolling scraps are attached, so that the rolling scraps adhere to the work rolls, and further, the work rolls to which the rolling scraps are attached The inventors have obtained knowledge that indentations corresponding to the rolling scraps can be generated on the rolled sheet by pressing the rolling scraps one after another on the rolling sheets that have passed through the rolling rolls. This indentation is repeated until the rolling scrap attached to the work roll falls off naturally. Therefore, indentations are continuously formed at a pitch according to the circumference of the work roll. As a result, it has been found that a coil material having indentations intermittently or continuously can be produced over the entire length of the wound magnesium alloy coil material. Moreover, this indentation was a magnitude | size according to the magnitude | size of rolling waste, and the knowledge that it was comparatively large (the maximum diameter was 0.5 mm or more) was acquired.

  For example, if a large amount of rolling oil is used as in the case of cold working steel or the like, the rolling waste can be washed away by this rolling oil. However, since the magnesium alloy performs warm working as described above, if a large amount of lubricant is used, the material is cooled by the lubricant and the rolling property is lowered. It is virtually impossible to wash away.

  Based on the above knowledge, in the method for producing a magnesium alloy coil material of the present invention, it is proposed to positively remove rolling scraps adhering to the work roll when producing a magnesium alloy coil material having excellent surface properties.

  The method for producing a magnesium alloy coil material according to the present invention comprises rolling a magnesium alloy with a rolling roll, winding the obtained rolled plate on a reel, and winding the rolled plate in a spiral shape. It relates to a method of manufacturing. The magnesium alloy constituting the rolled plate contains Al in excess of 7.2% by mass. And in the manufacturing method of the magnesium alloy coil material of this invention, the work roll which contacts the rolling plate which passed the said rolling roll and performs a predetermined effect | action on the said rolling plate between the said rolling roll and the said reel is at least. One of the work rolls is disposed at a position closest to the rolling roll, and the rolling scrap adhering to the surface of the latest work roll is removed.

  The manufacturing method of the magnesium alloy coil material of the present invention produces rolling scraps, and further removes the rolling scraps from the latest work roll even when the rolling scraps adhere to the surface of the nearest work roll arranged near the rolling roll. For this reason, it is possible to effectively reduce the occurrence of large indentations caused by pressing the rolling scraps against the rolled plate with the latest work roll. Therefore, the manufacturing method of the magnesium alloy coil material of the present invention can produce a magnesium alloy coil material (typically, a magnesium alloy coil material of the present invention described later) having no large wrinkles (indentation) and excellent surface properties. For example, the removal of rolling debris can be achieved by bringing a column-shaped member into sliding contact with a recent work roll or a rolled plate in one embodiment described later, and entwining or damming the rolling debris with this member, so that the rolling debris accumulates to some extent. Then, it can be performed by removing (throwing away) the rolling scraps as appropriate. In addition, the magnesium alloy coil material obtained by the method for producing a magnesium alloy coil material of the present invention can be (1) sufficiently removed wrinkles by light polishing, and (2) it is not necessary to cut and remove the wrinkles. (3) It is possible to reduce the amount of material discarded and the amount of polishing by cutting. From these points, the manufacturing method of the magnesium alloy coil material of the present invention is excellent in surface properties and can manufacture a long magnesium alloy coil material with high productivity. Furthermore, a magnesium alloy coil material that is more excellent in surface properties can be produced by subjecting the obtained magnesium alloy coil material to light polishing that gives a metallic luster.

The magnesium alloy coil material of the present invention is obtained by winding a plate made of a magnesium alloy in a spiral shape, the magnesium alloy contains more than 7.2% by mass of Al, and the plate has a maximum diameter of 0.5 mm or more. The abundance of the indentation is 5 / m ² or less.

  The magnesium alloy coil material of the present invention has few large wrinkles (indentations), is small even with wrinkles, and has excellent surface properties. In addition, the magnesium alloy coil material of the present invention is superior in surface properties, so that it is unnecessary to cut and remove the wrinkles and polishing with a large amount of polishing, and is excellent in productivity and long. Such a magnesium alloy coil material of the present invention and a magnesium alloy coil material obtained by the above-described method for producing a magnesium alloy coil material of the present invention (hereinafter collectively referred to as the coil material of the present invention) are subjected to press working. It can utilize suitably for the raw material of the magnesium alloy member (plastic processing member) to which plastic processing (secondary processing), such as, is given. Moreover, since the coil material of this invention is comprised from a elongate board | plate material (rolled board), it is anticipated that it can contribute to the mass production of the said magnesium alloy member. Furthermore, the obtained magnesium alloy member is also expected to be excellent in surface properties.

  As one form of this invention, the form in which the said magnesium alloy contains 8.3 mass% or more and 9.5 mass% or less of Al is mentioned.

  A magnesium alloy containing Al in the above specific range is excellent in mechanical properties (particularly strength) and corrosion resistance. Therefore, the magnesium alloy coil material of the above form is excellent in surface properties, and also in strength and corrosion resistance. The manufacturing method of the magnesium alloy coil material of the said form can manufacture the magnesium alloy coil material which is excellent also in an intensity | strength and corrosion resistance besides being excellent in surface property.

  As one form of the magnesium alloy coil material of the present invention, a form in which the plate material made of the magnesium alloy has a tensile strength of 270 MPa to 450 MPa and a 0.2% proof stress of 220 MPa to 350 MPa.

  Since the said board | plate material is excellent in intensity | strength, it can utilize suitably for the raw material of a magnesium alloy member (plastic working member). As for the said board | plate material with which the tensile strength and 0.2% yield strength satisfy | fill the above-mentioned specific range, a rolled sheet is mentioned, for example.

  As one form of the manufacturing method of the magnesium alloy coil material of this invention, the form which removes the rolling waste adhering to at least one of the upper surface and lower surface of a rolling plate which exists further from the said rolling roll to the said nearest work roll. Can be mentioned.

  The said form removes rolling waste, before the rolling waste adhering to the rolling plate by conveyance of the rolling plate is conveyed by the nearest work roll. Therefore, since the said form can reduce the rolling scrap itself adhering to the latest work roll, generation | occurrence | production of the impression by rolling scrap can be reduced effectively, and the magnesium alloy coil material which is excellent in surface property can be manufactured.

  As one form of the manufacturing method of the magnesium alloy coil material of this invention, the said latest work roll is the deflector roll which adjusts the winding angle of the said rolled sheet, the deflector roll for maintaining the said rolled sheet, and the said rolled sheet The form which is any one of the tension meter rolls which measure distribution of applied tension is mentioned.

  There can be various work rolls arranged between the rolling roll and the reel for winding. In addition, the arrangement order of the work rolls, the number of use, and the like can be appropriately selected. When manufacturing the magnesium alloy coil material, if the pinch roll is used, it is easy to keep the temperature of the material after passing through the rolling roller and before winding up to a certain level. Therefore, it is possible to take up warmly and suppress the occurrence of cracks during winding. When a deflector roll is used in the production of the magnesium alloy coil material, the winding angle of the rolled plate to the reel can be adjusted according to the thickness wound on the reel when the rolled plate is wound in a multilayer shape. Therefore, it can suppress that an excessive bending etc. are added to the rolled sheet before winding. When manufacturing a magnesium alloy coil material, if a tension meter roll is used, it is possible to reliably grasp the distribution in the plate width direction of the tension associated with the abnormality in flatness of the rolled plate (variation in flatness). Based on the measured distribution, using a mechanism such as a roll bender, the flatness of the rolled plate can be adjusted during rolling, and a coil material with excellent flatness can be obtained. Regardless of the case where the latest work roll is any of the above-described cases, the above-described form can produce a magnesium alloy coil material that has few cracks and deformation and is excellent in surface properties.

  As one form of the manufacturing method of the magnesium alloy coil material of this invention, the removal of the rolling waste adhering to the said latest work roll is performed by making the felt contact with the said latest work roll, and entwining the said rolling waste with the said felt. A form is mentioned.

  The above-mentioned form uses a soft material such as felt as a rolling scrap removing member so that the rolling scrap can be sufficiently entangled and rolled without substantially wrinkling the nearest work roll by the removing member. Debris can be removed.

  As one form of the manufacturing method of the magnesium alloy coil material of this invention, the form which removes the rolling waste adhering to the said rolled sheet is made by making a felt contact with the said rolled sheet and entwining the said rolled scrap with the said felt. Can be mentioned.

  The said form is a structure which makes the rolling scrap removal member contact a rolling plate directly. In the above embodiment, the material of the removal member is made of a soft material such as felt, so that the rolled plate is not substantially attached by the removal member itself, and the rolled up scraps are pressed against the rolled plate. Rolling scraps can be removed without attaching.

  As one form of the manufacturing method of the magnesium alloy coil material of this invention, the form which removes the said rolling waste using a plate-shaped scraper or a wiping roll is mentioned.

  As described in Patent Document 2, a plate scraper and a wiping roll are used for removing rolling oil and are expected to be used for removing rolling scraps. In particular, when a plate scraper or wiping roll made of a material harder than felt such as resin is used, it is expected that rolling scraps can be easily damped. In addition, although there exists a possibility that a rolling plate may be wrinkled with the plate-shaped scraper which consists of a hard material, this wrinkle is shallow enough to be removed enough by light grinding | polishing.

  The magnesium alloy coil material of the present invention is excellent in surface properties. The method for producing a magnesium alloy coil material of the present invention can produce a magnesium alloy coil material having excellent surface properties with high productivity.

It is a schematic block diagram of the manufacturing apparatus used for the manufacturing method of the magnesium alloy coil material which concerns on Embodiment 1. FIG. (A) is a schematic block diagram of the manufacturing apparatus used for the manufacturing method of the magnesium alloy coil material which concerns on Embodiment 2, (B) demonstrates the state which has arrange | positioned the plate side removal member provided in this manufacturing apparatus in the rolling plate. It is a schematic plan view to do.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The same code | symbol in a figure shows the same name thing.

[Embodiment 1]
With reference to FIG. 1, the manufacturing method of the magnesium alloy coil material which concerns on Embodiment 1 is demonstrated. In this manufacturing method, a material plate 1b made of a magnesium alloy is rolled by rolling rolls 10u and 10d, and the obtained plate material 1 (rolled plate) is wound up in a spiral shape by a reel 17 to produce a magnesium alloy coil material. It is. The manufacturing method according to the first embodiment is characterized in that the rolling waste adhering to the surface of the work roll (here, the pinch roll 13) arranged in the immediate vicinity of the rolling rolls 10u and 10d is removed. For the implementation of this manufacturing method, a magnesium alloy coil material manufacturing apparatus 100A shown in FIG. 1 can be suitably used.

  Hereinafter, the material plate 1b used for rolling will be described first, and then the manufacturing apparatus 100A and then the magnesium alloy coil material to be manufactured will be described in detail.

(Material)
The magnesium alloy constituting the material plate 1b is an Mg—Al-based alloy containing Al in excess of 7.2 mass%. This magnesium alloy is excellent in corrosion resistance and mechanical properties such as strength and hardness (rigidity) due to its high Al content. Although the content of Al tends to be excellent in corrosion resistance and mechanical properties as the content is larger, the content of Al is more than 12% by mass, and more preferably 11% by mass or less, because plastic workability is deteriorated when it exceeds 12% by mass. Other additive elements were selected from Zn, Mn, Si, Be, Ca, Sr, Y, Cu, Ag, Sn, Li, Zr, Ce, Ni, Au, and rare earth elements (excluding Y and Ce). More than seed elements. Examples of the content of each element include 0.01% by mass to 10% by mass, and further 0.1% by mass to 5% by mass. In particular, a total of at least one element selected from Si, Sn, Y, Ce, Ca and rare earth elements (excluding Y and Ce) is 0.001% by mass or more, preferably a total of 0.1% by mass or more and 5% by mass. % Or less of the magnesium alloy is excellent in heat resistance and flame retardancy. Examples of the impurities in the magnesium alloy include Fe.

  More specific compositions of Mg-Al alloys include, for example, AZ-based alloys (Mg-Al-Zn-based alloys, Zn: 0.2 mass% to 1.5 mass%) in ASTM standards, AM-based alloys (Mg -Al-Mn alloy, Mn: 0.15 mass% to 0.5 mass%), AS alloy (Mg-Al-Si alloy, Si: 0.2 mass% to 6.0 mass%), AX Alloy (Mg—Al—Ca alloy, Ca: 0.2 mass% to 6.0 mass%), AJ alloy (Mg—Al—Sr alloy, Sr: 0.2 mass% to 7.0 mass%) %). In addition, Mg-Al-RE alloys (RE: rare earth elements, RE: 0.001% by mass to 5% by mass, preferably 0.1% by mass or more) can be used.

  Among Mg-Al alloys, Mg-Al alloys containing Al in the range of 8.3 mass% to 9.5 mass% and Zn in the range of 0.5 mass% to 1.5 mass% are corrosion resistant and mechanical. It is preferable because of its excellent characteristics. Typically, an AZ91 alloy or a magnesium alloy containing Al and Zn corresponding to the AZ91 alloy (for example, AZX911) can be given.

  The plate material 1 (rolled plate) obtained by rolling the material plate 1b made of the magnesium alloy substantially maintains the composition of the material plate 1b.

  A cast coil material obtained by winding a long cast plate made of the above-described magnesium alloy can be suitably used for the material plate 1b used for rolling. The cast coil material can be obtained, for example, by producing a long cast plate from the above-described magnesium alloy by a continuous casting method such as a twin roll casting method and winding the cast plate in a spiral shape.

  By using a continuous casting method capable of rapid solidification, it is possible to reduce oxides and segregation, and to suppress the formation of coarse crystal precipitates of more than 10 μm. In particular, the twin-roll continuous casting method is excellent in rigidity and thermal conductivity, has little segregation, and can easily form a cast plate having excellent rolling properties (see Patent Document 1).

  The thickness, width, and length of the cast plate can be appropriately selected. For example, when the thickness is 10 mm or less, further 7 mm or less, particularly 5 mm or less, segregation or the like hardly occurs and the strength is excellent. For example, when a long cast plate having a length of 30 m or more, further 50 m or more, particularly 100 m or more, or a wide cast plate having a width of 100 mm or more, further 200 mm or more, particularly 250 mm or more is used as the material plate 1b, the long plate is used. A rolled plate or a wide rolled plate can be produced.

  Or the raw material board 1b can be made into the heat processing coil material which heat-processed further the solution treatment to the said cast coil material. Examples of the heat treatment conditions include heating temperature: 350 ° C. to 420 ° C., holding time: 1 hour to 40 hours. By this heat treatment, precipitates can be dissolved to improve mechanical properties and rollability (see Patent Document 1). Alternatively, when performing multiple passes of rolling, the material plate 1b can be a rolled plate.

(manufacturing device)
The manufacturing apparatus 100A includes a rolling mill 10 including rolling rolls 10u and 10d for rolling the material plate 1b, a reel 17 for winding the rolled plate material 1 (rolled plate), and from the rolling mill 10 to the reel 17. And a work roll (a pinch roll 13 and a deflector roll 15 in FIG. 1) that contact the plate 1 and apply a predetermined action to the plate 1. The manufacturing apparatus 100A unwinds the material coil material (the material plate 1b wound up), travels the long material plate 1b, performs rolling on the material plate 1b through the rolling mill 10, and makes the long material. This is an apparatus for manufacturing a plate material 1 and finally winding up the plate material 1 to manufacture a coil material. And 100 A of manufacturing apparatuses are provided with the roll side removal member 20 which removes the rolling waste which contacted the surface of the work roll (here pinch roller 13) nearest to the rolling mill 10 among work rolls. And The roll-side removing member 20 is disposed so as to be in sliding contact with the surface of the work roll, and removes the rolling debris from the surface by entwining or blocking the rolling debris attached to the surface of the work roll.

<Rolling mill>
The rolling mill 10 can use an appropriate one capable of rolling a magnesium alloy. Although the rolling mill 10 shown in FIG. 1 shows an example including a pair of rolling rolls 10u and 10d arranged to face each other, the rolling mill 10 can include a plurality of pairs of rolling rolls so that multistage rolling is possible. Moreover, if the rolling rolls 10u and 10d have a heatable configuration, the material plate 1b can be rolled while the temperature of the material plate 1b is sufficiently high. As a result, the occurrence of cracks during rolling can be reduced, the amount of rolling waste generated can be reduced, and a magnesium alloy coil material having excellent surface properties can be easily manufactured. The rolling rolls 10u and 10d are provided with power and controlled in operation by a roll driving unit (not shown). Examples of the roll drive unit include a power source such as a motor and a roll control unit that controls ON / OFF of rotation operation, the number of rotations (rotation speed), the gap distance between the rolling rolls 10u and 10d, and the like.

<Reel>
Each of the reel for feeding (not shown) and the reel 17 for winding includes a winding drum around which a plate is wound, and a flange protruding from the surface of the winding drum. These reels are provided with power and controlled in operation by a reel driving unit (not shown). Examples of the reel drive unit include a power source such as a motor and a reel control unit that controls ON / OFF of rotation operation, the number of rotations (rotation speed), the rotation direction, and the like. The material coil material is arranged on the reel for feeding, the material plate 1b is fed out, and the plate material 1 (rolled plate) passed through the rolling mill 10 is wound up by the winding reel 17, that is, the material is placed between the two reels. By rolling the plate 1b and rotating the reel in the same direction, the material plate 1b and the subsequent rolled plate 1 can be run. When rolling a plurality of passes, so-called reverse rolling can be performed. In reverse rolling, the above-mentioned two reels are alternately switched between feeding and winding, the rotation direction of each reel is reversed, the traveling direction of the plate spanned between both reels is reversed, and the above plate Is a method of rolling while reciprocating between both reels. Reverse rolling can continuously roll a plurality of passes by reversing the rolling direction and is excellent in coil material productivity.

<Work roll>
In the manufacturing apparatus 100 </ b> A, the work roll disposed in front of the rolling machine 10 in the traveling direction of the plate 1 (winding reel 17 side) is used for heat retention of the rolled plate (see Patent Document 1) and tension adjustment. Examples thereof include a pinch roll 13, a deflector roll 15 that changes the winding angle of the rolled plate, and a tension meter roll (not shown) that measures the distribution of tension applied to the plate material 1.

  The heat-insulating pinch roll 13 is heated to a predetermined temperature by incorporating heating means such as a heater, a circulation mechanism through which the heated fluid is circulated, and the like. By bringing the heated pinch roll 13 into contact with the plate material 1, the plate material 1 can be heated or the temperature of the plate material 1 can be suppressed from being lowered (the temperature of the plate material 1 can be maintained). In the example shown in FIG. 1, a pair of pinch rolls 13u and 13d arranged to face each other is provided, and the upper and lower surfaces of the plate 1 are sandwiched between the pinch rolls 13u and 13d. By this structure, the upper surface and lower surface of the board | plate material 1 can be heated, or a temperature fall can be suppressed. Moreover, the tension | tensile_strength added to the board | plate material 1 can also be adjusted by adjusting the pressure when pinching the board | plate material 1 with the pinch rolls 13u and 13d. When the temperature of the rolled sheet material 1 is set to a somewhat high temperature (for example, about room temperature to about 250 ° C. or less, preferably about 100 ° C. to 200 ° C.) using the pinch roll 13, the sheet material 1 is taken up warmly. It is easy to wind up and hard to break.

  When the plate material 1 is thick, when the plate material 1 is sufficiently kept warm, or when the distance to winding is long, a plurality of pinch rolls 13 can be arranged so as to be aligned in the traveling direction of the plate material 1. When heating by the pinch roll 13 is unnecessary, the pinch roll is used only for tension adjustment. If heating and tension adjustment are not required, the pinch roll 13 can be removed or omitted.

  The deflector roll 15 applies a predetermined bending (bending along the bending radius of the deflector roll 15) to the plate material 1 to change the angle of the plate material 1, and the angle of the plate material 1 so that the plate material 1 can be smoothly wound by the reel 17. Make adjustments. In the example illustrated in FIG. 1, the deflector roll 15 is disposed so as to be in contact with the upper surface of the plate material 1, but the deflector roll 15 may be disposed so as to be in contact with the lower surface of the plate material 1. The deflector roll 15 is arranged according to the position of the reel 17 and the angle at the time of winding. When adjustment of the angle at the time of winding is unnecessary, the deflector roll 15 can be removed or omitted.

  A tension meter roll (not shown) is used for measuring a tension distribution applied to the plate 1. Typically, a sensor (for example, a plurality of load cells) is mounted inside the tension meter roll, the load distribution corresponding to the tension distribution of the plate 1 is detected by the sensor, and the tension distribution is measured using this detection signal. . According to the measured tension distribution, the flatness of the coil material during rolling can be controlled by optimizing the tension distribution of the plate 1 with a roll bender or the like. If tension distribution measurement is not required, the tension meter roll can be omitted.

  Examples of the constituent material of the work roll described above include materials that do not react with the magnesium alloy and are not easily deformed by heat during warm rolling. Typically, steel such as tool steel is used.

<Roll-side removal member>
The roll-side removal member 20 that removes rolling scraps (not shown) attached to the surface of the work roll described above includes a dam portion 21 that is disposed so as to be in sliding contact with the work roll, and a support portion 23 that supports the dam portion 21. With.

  Various materials can be used for the weir portion 21. In particular, a felt made of natural fiber or synthetic fiber is preferable as a constituent material at a position in contact with the work roll. Since the felt is softer than the above-described tool steel or the like, it is expected that the felt is difficult to be wrinkled even when it is in contact with the work roll, or is not substantially wrinkled. Moreover, since it is fibrous, rolling waste can be removed by entwining the rolling waste. In addition, it is expected that the rolling waste can be removed by blocking the rolling waste to some extent. Examples of the constituent material in contact with the work roll include soft materials such as (industrial) nonwoven fabrics and woven fabrics other than felt. The constituent material of the dam portion 21 may be a resin (for example, a fluororesin such as PTFE).

  A specific form of the dam portion 21 is, for example, a columnar material (columnar wiper) such as a prism or cylinder (in FIG. 1, a prismatic wiper is shown). The width of the columnar wiper (the length along the axial direction of the work roll) can be equal to or greater than the axial length of the work roll. In particular, felt-made columnar wipers are preferable because they can remove rolling scraps and prevent wrinkles as described above, and are easy to manufacture.

  Alternatively, the dam portion 21 may be a plate scraper or a wiping roll. In particular, since the plate scraper and the wiping roll are made of the above-described resin, the rigidity is higher than that of the above-described felt. Therefore, it is expected that the rolling scrap can be removed by damming the rolling scrap. The plate scraper is (1) only the contact point with the work roll is formed with the above-mentioned felt and the other part is made of resin, and (2) the surface of the core material made of steel such as stainless steel is used. It can be composed of a composite material covered with a silicone resin, or (3) composed of an elastic body such as silicone rubber. Of course, a felt plate scraper or a wiping roll can be used. In addition, in a brush (especially a rotating brush), hard bristle material or thick bristle material presses the rolling waste held between the bristle materials to the plate material 1 or the plate material 1 is wrinkled by the held rolling waste. In addition, there is a risk that the rolling scraps may be firmly held, which is not preferable.

  The support part 23 can utilize suitably the structure which can support the dam part 21 so that it may slidably contact with the surrounding surface of a work roll. For example, the support part 23 is comprised with a metal piece etc., and the structure which can fix the arrangement position of the dam part 21 so that it cannot change is mentioned. In this case, the support portion 23 can have a simple configuration. Or the support part 23 can be set as the structure which comprises elastic bodies, such as a compression spring, a pneumatic cylinder, a hydraulic cylinder, etc., and supports the dam part 21 so that the arrangement position of the dam part 21 can be fluctuate | varied. In this case, it becomes possible to adjust the load (pressing force) of the dam portion 21 with respect to the work roll, and it is difficult to braze the surface of the work roll by the contact of the dam portion 21. Or the support part 23 is comprised with a rod-shaped metal member etc., the structure which suspends the dam part 21 and supports so that the dam part 21 contacts a work roll with the dead weight of the dam part 21 is also the surface of a work roll. It is difficult to identify.

  As for the arrangement position of the roll-side removal member 20 with respect to one work roll, an appropriate location where the rolling scraps can be entangled or dammed can be selected. Typically, there is a portion selected from a semicircular arc region (an upper half arc region in the upper pinch roll 13u shown in FIG. 1) located on the side away from the plate 1 in the work roll. In the example illustrated in FIG. 1, two roll-side removal members 200 and 201 are disposed on the upper pinch roll 13 u disposed so as to be in contact with the upper surface of the plate 1. Both roll-side removal members 200 and 201 are arranged in the above-described arc region of the upper half, and are arranged at symmetrical positions with respect to the vertical to the upper surface of the plate 1, and the center of the pinch roll 13 u (not shown) The angle formed by both members 200 and 201 is about 90 °. The angle formed above can be changed as appropriate. Moreover, both members 200 and 201 may be disposed at asymmetric positions.

  The number and arrangement position of the roll-side removal members 20 arranged for one work roll and the total count of the roll-side removal members 20 included in the manufacturing apparatus 100A can be selected as appropriate. For example, the roll side removal members 210 and 211 may be arranged on the lower pinch roll 13d, or the roll side removal members 200, 201, 210, and 211 are arranged on both the pinch rolls 13d and 13u, respectively. May be. Further, two roll-side removal members 200 and 201 may be arranged on the upper pinch roll 13u, and one roll-side removal member 20 may be arranged on the lower pinch roll 13d. That is, the number of roll-side removal members 20 arranged on the upper and lower pinch rolls 13d and 13u may be different. Here, the rolling waste adhering to the lower surface of the plate member 1 may fall due to its own weight. On the other hand, the rolling debris attached to the upper surface of the plate 1 is not lost except for positive removal. Therefore, it is expected that the rolling scrap attached to the surface of the plate material 1 can be effectively removed by increasing the number of roll-side removal members 20 arranged on the upper pinch roll 13u.

  When the work roll arranged nearest to the rolling mill 10 is, for example, the deflector roll 15 in the case where the pinch roll 13 is not provided or the arrangement order of the work rollers is different, for example, the work roll is arranged with respect to the pinch roll 13u. Similarly to the case, the roll-side removal members 220 and 221 may be disposed with respect to the deflector roll 15. When both the pinch roll 13 and the deflector roll 15 are provided, the roll-side removal member 20 can also be arranged for the deflector roll 15 in addition to the pinch roll 13. When there are a plurality of work rolls along the traveling direction of the plate material 1, in addition to the work rolls arranged in the immediate vicinity of the rolling mill 10, other work rolls, that is, the front of the plate material 1 in the traveling direction (for winding) If the roll-side removal member 20 is also arranged on the work roll arranged on the reel 17 side, the rolling scraps that have been missed by the latest work roll can be removed. Therefore, since the area | region where the impression by rolling scraps is formed in the board | plate material 1 can be reduced, it is anticipated that the board | plate material 1 with few large wrinkles and excellent in surface property can be manufactured longer. The matter described in the case of the above-described deflector roll 15 can also be applied to the case where the work roll disposed in the immediate vicinity of the rolling mill 10 is a tension meter roll (not shown).

<Others>
The manufacturing apparatus 100A accommodates a reel around which the material plate 1b is wound, and a heat box (not shown) that can heat the material plate 1b to a desired temperature, and a heat retention for maintaining the temperature of the traveling plate 1 A cover can be provided. By providing a heat box, a heat insulation cover, etc., the temperature drop of the board | plate material 1 can be suppressed and rolling property and the ease at the time of winding can be improved.

(Manufacturing procedure of coil material)
In order to manufacture a magnesium alloy coil material using the manufacturing apparatus 100A having the above-described configuration, the manufacturing is performed as follows. The material coil material winding the material plate 1b is heated in advance to a predetermined temperature by a heat box or a separately prepared heating means as described above.

  The material coil material is attached to the reel for feeding, the material coil material is rewound, and one end of the material plate 1b is wound as it is with the take-up reel 17 (this end is not rolled), and the material plate. 1b and the rolled plate material 1 are allowed to travel between both reels. And the raw material board 1b is sequentially introduce | transduced into the rolling mill 10, and rolling by the rolling rolls 10u and 10d is started. As both reels rotate and the material plate 1b travels, the material plate 1b is sequentially rolled into a rolled plate (plate material 1). The plate material 1 that has passed through the rolling mill 10 is appropriately adjusted in tension and kept warm by a pinch roll 13 in the middle, bent to an appropriate angle by a deflector roll 15, and finally wound on a reel 17.

  At the time of rolling, the edge of the plate material 1 is cracked to produce rolling scraps. Further, the rolling scraps adhere to the surface (particularly the upper surface) of the plate member 1 and are sent to the pinch roll 13 while adhering. In some cases, rolling scraps may adhere to the surface. However, in the manufacturing apparatus 100 </ b> A, the attached rolling scrap comes into contact with the roll-side removal member 20 by the rotation of the pinch roll 13 and is entangled or dammed up. By removing the rolling debris by entanglement and damming, the pinch roll 13 can come into contact with the plate 1 in a region where the rolling debris is not attached. Therefore, it can reduce that the pinch roll 13 presses a rolling scrap against the board | plate material 1, and forms a big indentation on the surface of the board | plate material 1. FIG. In addition to the upper pinch roll 13u, when the lower pinch roll 13d is also provided with the roll side removing member 20, the formation of large indentations can be reduced on both the upper and lower surfaces of the plate member 1. Furthermore, when the deflector roll 15 and the tension meter roll are also provided with the roll-side removal member 20, the number of large indentations that can be formed on the surface of the plate 1 can be further reduced.

  By the above-described winding, a magnesium alloy coil material in which a long rolled plate (plate material 1) is wound is obtained.

  The rolling scrap removed (entangled or dammed) by the roll-side removal member 20 is removed at an appropriate time. For example, if it is removed after one pass of rolling is completed, it is easy to prevent the rolling scraps from re-adhering to the plate 1 when removed.

(Rolling conditions)
Rolling by the rolling mill 10 is at least one pass rolling as warm rolling. The condition of the warm rolling is as follows: temperature of the material plate 1b immediately before being supplied to the rolling rolls 10u and 10d: 150 ° C. or higher and 400 ° C. or lower (preferably 350 ° C. or lower, more preferably 300 ° C. or lower, especially 280 ° C. or lower) Per roll reduction: 5% to 40%. By setting the specific temperature range as described above, (1) the plastic workability of the material plate 1b can be improved, the cracks at the edge can be reduced, and the generation of rolling debris can be reduced. (2) the rolling reduction per pass Can be increased (for example, about 10% to 30%), the productivity of the coil material can be increased, (3) the deterioration of the surface properties due to seizure, etc. can be suppressed, (4) the thermal deterioration of the rolling roll can be suppressed, There are effects such as. Moreover, when not only the raw material board 1b but the rolling rolls 10u and 10d are heated, it is easy to suppress the temperature fall of the raw material board 1b, or to reduce the crack of an edge part more. In addition, warm rolling can be performed using known rolling conditions. In addition, when performing rolling with a small rolling reduction by finish rolling etc., cold rolling can also be performed using the manufacturing apparatus 100A.

  When a lubricant is used for rolling, the friction between the material plate 1b and the rolling rolls 10u and 10d can be reduced and rolling can be performed satisfactorily. The lubricant may be applied to the rolling rolls 10u and 10d using, for example, a brush or a wiper.

  When rolling a plurality of passes, the thickness of the rolled plate is reduced, the average crystal grain size of the structure constituting the rolled plate is reduced (for example, 10 μm or less, preferably 5 μm or less), or plastic working such as press working. And can improve sex. The number of passes, the reduction rate of each pass, and the total reduction rate can be appropriately selected so that a plate material 1 (rolled plate) having a desired thickness can be obtained.

  In the above-described procedure, the case where the warm rolling is performed for one pass has been described. When performing multiple passes of warm rolling, for example, using the heat box described above, and performing reverse rolling with the two reels reversed, the coil material can be manufactured with high productivity.

(Magnesium alloy coil material)
The magnesium alloy coil material obtained through the above-described procedure is constituted by a plate material 1 (rolled plate) wound in a spiral shape. The thickness, width, and length of the plate material 1 can be set to desired values by adjusting the rolling conditions. In particular, when this coil material is used as a material of a plastic working member such as a press working member, a thin plastic working member having a thickness of 0.1 mm to 2.0 mm, particularly 0.3 mm to 1.2 mm is obtained. can get. The coil material composed of a long plate having a length of the plate material 1 of 50 m or more, further 100 m or more, 200 m or more, or 400 m or more is continuously supplied to the plastic working device when used as the material of the plastic working member described above. It is possible to mass-produce plastic processed members. The coil material composed of a wide plate having a width of 100 mm or more, further 200 mm or more, particularly 250 mm or more is used as a material for the above-mentioned plastic working member. It is possible to manufacture plastic working members of various sizes up to large ones such as these parts. A heavy coil material having a magnesium alloy coil material weight of 100 kg or more, further 200 kg or more depends on the width and thickness of the plate material 1, but the longer the coil material is, the smaller the thickness (for example, 1 mm or less). The coil material is composed of a plate (for example, a total length of 200 m or more, further 400 m or more) or a wide plate (for example, a width of 100 mm or more, further 200 mm or more). When such a coil material is used as a material for the above-mentioned plastic working member, it is possible to produce plastic working members of various sizes as described above, or to contribute to mass production of the plastic working member. In addition, the winding diameter (inner diameter) of the coil material can be appropriately selected.

  The plate material 1 constituting the magnesium alloy coil material is rolled, so that a cast plate made of a magnesium alloy having the same composition or a magnesium alloy having a low Al content (for example, AZ31 alloy or AZ61 alloy). Compared with a rolled sheet, the mechanical properties are excellent. For example, the plate 1 constituting the magnesium alloy coil material may have a form satisfying tensile strength: 270 MPa to 450 MPa and 0.2% proof stress: 220 MPa to 350 MPa. Furthermore, the form which satisfy | fills elongation: 1% or more and 15% or less is mentioned.

And the board | plate material 1 which comprises the said magnesium alloy coil material does not have a big indentation. Specifically, the abundance of indentations having a maximum diameter of 0.5 mm or more is 5 pieces / m ² or less. That is, even if the plate material 1 has an indentation, most of them are small indentations having a maximum diameter of less than 0.5 mm. Therefore, indentations can be sufficiently eliminated by light polishing (polishing with a small amount of polishing) such as polishing for producing a metallic luster. The maximum diameter of the indentation existing in the plate material 1 is preferably as small as possible, and is preferably 2 mm or less, and more preferably 1 mm or less. In addition, the smaller the indentation having the maximum diameter of 0.5 mm or more, the more preferable, and the most not present. A method for measuring the maximum diameter and abundance of the indentation will be described later.

(effect)
The manufacturing method of the magnesium alloy coil material of the present invention of Embodiment 1 manufactures a magnesium alloy coil material by winding a plate material (rolled plate) obtained by rolling (typically warm rolling) a magnesium alloy. In doing so, even if rolling scraps are generated during the rolling and adhere to the surface of the work roll, the roll scraps are removed from the work roll by the roll-side removal member 20. Therefore, the manufacturing method of the magnesium alloy coil material of this invention can reduce effectively that rolling scraps are pressed by the work roll on the plate 1 which was rolled, and an indentation is formed. Therefore, the obtained magnesium alloy coil material and the magnesium alloy plate obtained by cutting the coil material to a predetermined length have few or substantially no indentations and are excellent in surface properties. In addition, since there is little or substantially no large indentation, it is not necessary to perform a large amount of polishing in order to eliminate wrinkles or to cut and remove portions of wrinkles, so that the yield can be improved. Therefore, by using the method for producing a magnesium alloy coil material of the present invention, a magnesium alloy coil material or a magnesium alloy plate having excellent surface properties can be produced with high productivity. The magnesium alloy coil material and the magnesium alloy plate can be suitably used as a material to be subjected to plastic working such as press working, and a magnesium alloy member having excellent surface properties can be obtained.

[Embodiment 2]
Embodiment 1 demonstrated the form which provides only the roll side removal member 20 which removes the rolling waste adhering to the work roll. In addition to the roll-side removal member 20, the production method of Embodiment 2 uses a production apparatus 100B having a plate-side removal member 30 as shown in FIG. is there. Hereinafter, the configuration and effects related to the plate-side removal member 30 will be described in detail, and detailed description of the configurations and effects overlapping with those of the first embodiment will be omitted.

<Plate side removal member>
The plate-side removal member 30 removes rolling scraps present on the surface of the plate material 1 (rolled plate) existing between the rolling mill 10 (rolling rolls 10u, 10d) and the latest work roll (here, the pinch roll 13). The member to be removed. The basic configuration of the plate-side removal member 30 is the same as that of the roll-side removal member 20, and includes a dam portion 31 disposed so as to be in sliding contact with the surface of the plate material 1, and a support portion 33 that supports the dam portion 31. Yeah.

  The constituent material of the weir part 31 is, for example, a felt or a resin molded body, like the weir part 21 included in the roll-side removal member 20. Examples of the form of the dam portion 31 include a columnar wiper, a plate scraper, and a wiping roll (in FIG. 2, a prismatic wiper is shown). In particular, since the weir portion 31 included in the plate-side removal member 30 is in direct contact with the plate material 1, it is preferable that the portion in contact with the plate material 1 is made of at least a soft material such as felt. When the dam portion 31 is made of a soft material such as felt, the rolling waste entangled by the dam portion 31 is not substantially pressed against the plate material 1, and the plate material 1 is difficult to be wrinkled.

When the weir portion 31 is a columnar wiper, a straight shape such as a general prism or cylinder is considered preferable. For example, when the columnar wiper has a V shape or a bow shape in plan view and faces the V-shaped convex side or the convex side of the bow toward the downstream side (forward in the traveling direction), the rolling waste is part of the dam portion 31. It is collected and collected. However, if the rolling scraps are excessively concentrated on a part of the plate material 1, the plate material 1 may be wrinkled by the accumulated rolling scraps. In the case where the weir portion 31 is a plate-shaped scraper, it is made of a resin or the like, and has a V shape or a bow shape in a plan view, and the V-shaped convex side or the convex side of the bow is directed rearward in the traveling direction of the plate material 1. It is expected that the rolling scraps that come into contact with the convex surface can fall to the outside of the plate 1. In this case, the width W ₃₀ (described later) of the plate scraper can be increased to some extent so that the rolling scraps can easily fall. When reverse rolling is performed in this form, the direction of the convex side such as a V-shape is reversed each time the traveling direction of the plate 1 is changed.

The width W ₃₀ of the dam portion 31 is preferably shorter than the width W _{1 of the} plate 1. The width refers to the length along the axial direction of the work roll (the length in the vertical direction in FIG. 2B). As described above, rolling scraps may be present at the edge of the plate 1 that has passed through the rolling mill 10 due to cracking. Therefore, placing the dam portion 31 over the entire width of the plate 1, that is, if the width W ₃₀ of the dam portion 31 and the width W ₁ and equal to or higher than that of the plate 1, or take twine, the amount of rolling debris or dammed There is a possibility that the plate material 1 is wrinkled by the accumulated rolling scraps, or the rolling scraps are scattered around. Moreover, when trimming and removing the edge part of the board | plate material 1 after rolling, it can accept to some extent that a flaw exists in an edge part. Therefore, in order to prevent the intensive rolling debris edge of the weir portion 31 is attached, the width W ₃₀ of the dam portion 31, shorter than the width W ₁ of the plate 1, and this short weir portion 31 However, it is preferable to arrange so as not to include the edge of the plate material 1 and to be located only in the central portion of the plate material 1 (see FIG. 2B). In this case, a region where the dam portion 31 is not disposed in the plate material 1: the width W _{e of the} edge portion is about 3 mm to 20 mm.

  The support portion 33 includes a configuration that fixes the arrangement position of the dam portion 31 so as not to fluctuate, a compression spring, a cylinder, and the like, like the support portion 23 included in the roll-side removal member 20, and the dam portion 31 for the plate material 1 It is possible to adopt a configuration in which the pressing force can be adjusted, a configuration in which it is suspended by its own weight, and the like. As described above, the dam portion 31 is in direct contact with the plate material 1. Therefore, if the latter pressing force is adjustable, the pressing force on the plate material 1 can be prevented from becoming excessively large. Therefore, it is possible to suppress the plate material 1 from being wrinkled by the plate side removing member 30 (weir portion 31), which is preferable.

  The arrangement position of the plate-side removal member 30 can be selected at any location between the rolling mill 10 and the nearest work roller. The number of the plate-side removal members 30 may be one as shown in FIG. For example, the plate-side removal members 300 and 301 can be juxtaposed so as to be lined up and down along the traveling direction of the plate material 1. In this case, for example, when removing the rolling waste entangled or dammed by one (upstream side in the traveling direction of the plate 1), the other (on the downstream side) plate-side removal member By 301, rolling waste can be entangled or dammed up. Moreover, when removing the rolling scraps entangled or dammed by one plate-side removal member 300, the other plate-side removal member 301 may be disposed. That is, the plurality of plate-side removal members 30 may be arranged only at a specific time such as when the plate-side removal member 30 is replaced. Alternatively, in the example shown in FIG. 2A, the plate-side removal member 300 is arranged only on the upper surface of the plate material 1, but the plate-side removal member 310 may be arranged on the lower surface of the plate material 1, The plate-side removal members 300 and 310 may be disposed on both surfaces of the plate material 1, respectively. For the same reason as the roll-side removal member 20, the number of the plate-side removal members 30 arranged on the upper and lower surfaces of the plate material 1 may be different. Further, when the plate-side removal member 30 is disposed on both surfaces of the plate material 1 and the plate material 1 is sandwiched by the plate-side removal member 30, there is a possibility that excessive pressing force acts on the plate material 1. It is preferable that the arrangement position of the plate-side removal member 30 arranged on the plate and the arrangement position of the plate-side removal member 30 arranged on the lower surface of the plate material 1 are shifted along the traveling direction of the plate material 1.

(Manufacturing procedure of coil material)
The procedure for manufacturing the magnesium alloy coil material using the manufacturing apparatus 100B including both the roll-side removal member 20 and the plate-side removal member 30 is the same as that of the first embodiment. However, at the time of rolling, in addition to the removal of rolling waste from the work roll by the roll-side removal member 20, the removal of rolling waste from the plate material 1 by the plate-side removal member 30 is performed. As described above, the rolling scraps removed (entangled or dammed) by the roll-side removal member 20 and the plate-side removal member 30 may be removed for each pass, for example.

(effect)
The method for producing a magnesium alloy coil material of the present invention of Embodiment 2 is to produce a magnesium alloy coil material by winding a plate material (rolled plate) obtained by rolling (typically warm rolling) a magnesium alloy. In doing so, even if rolling scraps are generated during rolling and adhere to the surface of the plate 1 or the surface of the work roll, the rolling scrap is removed from the plate 1 by the plate-side removal member 30 and is removed from the work roll by the roll-side removal member 20. It has a multi-stage removal structure that removes rolling scraps. Since the rolling waste that can be conveyed to the work roll side can be removed by the plate-side removal member 30, this manufacturing method can reduce the rolling waste that can adhere to the roll-side removal member 20 itself. Therefore, in this manufacturing method, it can reduce more effectively that a rolling waste is pressed by the work roll on the plate material 1 which was rolled, and an impression is formed. Magnesium alloy coil materials and magnesium alloy plates obtained by this production method have fewer or substantially no indentations and are superior in surface properties. Moreover, by using this manufacturing method, a magnesium alloy coil material and a magnesium alloy plate excellent in surface properties can be manufactured with higher productivity. And this magnesium alloy coil material and a magnesium alloy plate can be used suitably for the raw material of a plastic working member, and the magnesium alloy member which is excellent in surface property is obtained.

[Test example]
Based on the manufacturing method of the magnesium alloy coil material of Embodiment 1 and 2 mentioned above, the magnesium alloy coil material was manufactured and the surface property was investigated.

  In this test, a molten magnesium alloy having a composition equivalent to AZ91 alloy (Mg-8.7% Al-0.65% Zn, all by mass%) was prepared, and a cast plate having a thickness of 4 mm was obtained by a twin roll casting machine. Were continuously produced and wound up to produce a cast coil material. The cast coil material was charged into a batch furnace and subjected to a solution treatment at 400 ° C. for 24 hours. The obtained solid solution coil material was used as a material coil material, and a plate material obtained by subjecting a material plate obtained by rewinding the material coil material to warm rolling of a plurality of passes under the following conditions was wound up. By the above process, a rolled coil material made of a rolled plate having a thickness of 0.6 mm, a width of 250 mm, and a length of 760 m was produced (200 kg). In this test, as one of the work rollers, a pinch roller for heat insulation (a pair of sets arranged so as to sandwich the rolled plate) was prepared. And this pinch roller was arrange | positioned in the position nearest to a rolling roller among the working rollers arrange | positioned from a rolling roller to the reel for winding. That is, this pinch roller is the latest work roller.

(Rolling conditions)
Reduction ratio: 5% / pass to 40% / pass Heating temperature of the material plate: 250 ° C. to 280 ° C.
Rolling roll temperature: 100 ° C to 250 ° C

  Sample No. using the manufacturing method of the first embodiment. In No. 1, a commercially available columnar felt was prepared. A roll-side removal member having a weir portion made of this columnar felt (columnar wiper) was prepared. And the roll side removal member was arrange | positioned so that the said dam part might slidably contact on the surface of an upper side nearest work roller (here pinch roller), and the above-mentioned multiple pass rolling was performed. Moreover, the rolling waste entangled by the weir part for each pass was removed.

Sample No. using the manufacturing method of the second embodiment. In sample 2, sample no. A roll side removal member having a felt columnar wiper similar to 1 was prepared. In addition, a commercially available columnar felt was prepared, and a plate-side removal member having a dam portion made of this columnar felt (columnar wiper) was also prepared. And sample no. In sample 2, sample no. 1, the roll-side removal member is disposed so that the weir portion is in sliding contact with the surface of the uppermost nearest work roller (here, pinch roller), and the upper surface of the rolled sheet existing between the rolling mill and the nearest work roller. The plate-side removal member was arranged so that the weir portion slidably contacted with each other, and the above-described multi-pass rolling was performed. The width W _{30 of the} weir part included in the plate-side removal member was made smaller than the width W _{1 of the} plate material (rolled plate), and the plate-side removal member was arranged so that the weir part did not contact the edge of the plate material. Moreover, the rolling waste entangled by the weir portion of each removing member was removed for each pass.

  Sample No. In 100, the above-described multiple passes of rolling were performed without arranging both the roll-side removal member and the plate-side removal member.

About the produced magnesium alloy coil material of each sample, the surface property was investigated as follows. The coil material after rolling is rewound, and a plate piece having a length of 300 mm is cut out from the outer periphery of the coil material. Every time 95 plate pieces were cut out, the following 5 plate pieces were extracted as evaluation samples, and the operation was repeated. Then, the number of indentations (hereinafter referred to as coarse indentations) having a maximum diameter of 0.5 mm or more was counted for the evaluation samples. Here, the impression was investigated about both surfaces of each sample for evaluation. In addition, since the shape of an indentation is an irregular shape, the largest length in each indentation was made into the maximum diameter. Then, the number of coarse indentations per 1 m ² was determined using 100 or more evaluation samples (here, 125). As a result, sample no. 100, the number of indentations having a maximum diameter of 0.5 mm or more is 20 / m ² , whereas the sample No. 1, No. 1 In both cases, the presence of indentations having a maximum diameter of 0.5 mm or more was 5 pieces / m ² or less, and there were few large wrinkles. In particular, sample No. 1 in which the rolling scraps were removed from both the work roll and the rolled plate. No. ² has an indentation amount of 3 pieces / m ² having a maximum diameter of 0.5 mm or more. Wrinkles larger than 1 (5 pieces / m ² ) were reduced. Sample No. 1, No. 1 For No. 2, the tensile strength (room temperature) and 0.2% proof stress (room temperature) were examined using a commercially available tensile test apparatus. As a result, sample no. 1 shows tensile strength of 282 MPa, 0.2% proof stress: 226 MPa, sample No. 1 No. 2 had a tensile strength of 278 MPa and a 0.2% proof stress of 221 MPa, both having excellent mechanical properties.

  Note that an evaluation facility such as a flaw detector having an image processing function can be used to measure the maximum diameter of the above-described indentation and the coarse indentation. In this case, the measurement of the maximum diameter of the indentation and the extraction of the coarse indentation can be easily performed continuously and with respect to the entire length of the coil material to be measured.

  Sample No. 1, when a roll-side removal member is further added to the lower pinch roll, the sample No. 2, the surface properties were examined for each of the cases where a plate-side removal member was added to the lower surface of the rolled plate. As a result, a magnesium alloy coil material excellent in surface properties was obtained with few large wrinkles on both the upper and lower surfaces of the rolled sheet.

  From the above test results, when the magnesium alloy is subjected to warm rolling for one pass or more to produce a magnesium alloy coil material, the rolling debris that can adhere to the work roller disposed at the position closest to the rolling roller is removed. Thus, it was confirmed that large wrinkles can be reduced and a magnesium alloy coil material having excellent surface properties can be obtained. Moreover, in addition to removing the rolling scraps from the work roller, removing the rolling scraps from the rolled plate can further reduce large wrinkles and obtain a high-quality magnesium alloy coil material with excellent surface properties. Was confirmed.

  In addition, this invention is not limited to embodiment mentioned above, In the range which does not deviate from the summary of this invention, it can change suitably. For example, the material of the roll-side removal member or the plate-side removal member, the arrangement position, the number, the thickness, width, length, etc. of the plate material constituting the magnesium alloy coil material can be appropriately changed.

  The magnesium alloy coil material of the present invention is a magnesium alloy member subjected to various plastic processing such as pressing, forging, bending and upsetting, for example, a constituent member of various electric / electronic devices (more specifically, For portable and small electrical and electronic equipment casings and reinforcing materials), automotive and aircraft transportation equipment components, various casings and cover exterior members, frame members, bags and other materials It can be suitably used. The manufacturing method of the magnesium alloy coil material of this invention can be utilized suitably for manufacture of the said magnesium alloy coil material of this invention.

DESCRIPTION OF SYMBOLS 1 Plate material 1b Material plate 100A, 100B Magnesium alloy coil material manufacturing apparatus 10 Rolling mill 10u, 10d Roll roll 13, 13u, 13d Pinch roll 15 Deflector roll 17 Reel 20, 200, 201, 210, 211, 220, 221 Roll side Removal member 21, 31 Weir part 23, 33 Support part 30, 300, 301, 310 Plate side removal member

Claims (3)

A magnesium alloy coil material obtained by winding a plate material made of a magnesium alloy in a spiral shape,
The magnesium alloy is an Mg-Al-based alloy containing Al in an amount of 8.3 mass% to 9.5 mass% and Zn in an amount of 0.5 mass% to 1.5 mass%,
The plate material is
The length is 50 m or more,
A magnesium alloy coil material having a maximum diameter of 0.5 mm or more and an abundance of indentations formed intermittently at a predetermined pitch of 5 pieces / m ² or less.
However, the amount of the indentation is determined by cutting out 100 or more evaluation samples from the magnesium alloy coil material at predetermined intervals, and counting the number of indentations having a maximum diameter of 0.5 mm or more with respect to these evaluation samples. Te, determined by calculating the number of indentations per 1 m ^2.   The magnesium alloy coil material according to claim 1, wherein the plate material made of the magnesium alloy has a tensile strength of 270 MPa to 450 MPa and a 0.2% proof stress of 220 MPa to 350 MPa.   The magnesium alloy coil material according to claim 1 or 2, wherein the plate material made of the magnesium alloy has a thickness of 2.0 mm or less.

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