KR20140002726A - Rolled magnesium alloy material, magnesium alloy member, and method for producing rolled magnesium alloy material - Google Patents

Abstract

Provided are an Mg alloy rolled material having a wide width and a uniform mechanical property in the width direction, an Mg alloy member formed by plastic working the Mg alloy rolled material, and a method for producing the Mg alloy rolled material. The manufacturing method of Mg alloy rolling material is a method of rolling and manufacturing Mg alloy material with a rolling roll. The width of the Mg alloy material is 1000 mm or more, and the rolling rolls have three or more regions in the width direction. Temperature control is performed for every area | region so that the difference of the maximum temperature and minimum temperature in the width direction of a rolling roll surface may be 10 degrees C or less. By making small the temperature difference of the whole width direction of a rolling roll, the fluctuation | variation of the rolling state of the width direction can be reduced. Therefore, Mg alloy rolling material with a substantially uniform mechanical characteristic in the width direction can be manufactured.

Description

Magnesium alloy rolled material, magnesium alloy member, and manufacturing method of magnesium alloy rolled material {ROLLED MAGNESIUM ALLOY MATERIAL, MAGNESIUM ALLOY MEMBER, AND METHOD FOR PRODUCING ROLLED MAGNESIUM ALLOY MATERIAL}

The present invention relates to a magnesium alloy rolled material, a magnesium alloy member, and a method for producing a magnesium alloy rolled material. In particular, the present invention relates to a magnesium alloy rolled material having a uniform mechanical property in the width direction even if the width of the rolled material is wide, a magnesium alloy member obtained by plastically processing the magnesium alloy rolled material, and a method for producing the magnesium alloy rolled material.

Background Art In recent years, magnesium (Mg) alloy plates have been used for housings of cellular phones and notebooks. Since Mg alloy is inferior in plastic workability, the casting material by the die casting method or the thixomolding method is mainstream. Usually, the cast material is rolled to improve the mechanical properties.

In patent document 1, rolling of the casting material manufactured by the twin roll continuous casting method of the magnesium alloy equivalent to the AZ91 alloy in ASTM specification is described. Specifically, the surface temperature of the Mg alloy material sheet immediately before inserting into a rolling roll and the surface temperature of the rolling roll are controlled and rolled to specific temperature, respectively.

Japanese Patent Laid-Open No. 2007-098470

As the use range of Mg alloy expands, development of the Mg alloy material of large size is calculated | required. According to the rolling described above, for example, when the width of the Mg alloy material is not very wide, the surface temperatures of the Mg alloy material and the rolling roll naturally tend to be uniform in the width direction. Therefore, fluctuation | variation does not produce easily in the rolling state in the width direction, and it becomes easy to become a Mg alloy rolling material with a uniform mechanical characteristic in the width direction. However, as the width of the alloying material became wider, especially when it became 1000 mm or more, it was difficult to make the mechanical properties uniform in the width direction. The reason for this is that the wider the width, the easier the heating state is to be maintained at the central portion of the Mg alloy material in the width direction at the time of rolling, and the easier it is to cool at the both ends. As a result, it is difficult to maintain a uniform heating state at the center and both ends, and a difference may occur in the rolled state.

This invention is made | formed in view of the said situation, One of the objectives is to provide the Mg alloy rolled material with a wide width and a uniform mechanical characteristic in the width direction.

Another object of the present invention is to provide an Mg alloy member using the Mg alloy rolled material.

Still another object of the present invention is to provide a method for producing the Mg alloy rolled material.

The Mg alloy rolling material of the present invention is obtained by rolling an Mg alloy material with a rolling roll and has a width of 1000 mm or more. Peak intensity of X-ray diffraction of the (002) plane, (100) plane, (101) plane, (102) plane, (110) plane, and (103) plane in the center portion in the width direction of the Mg alloy rolled material Let I _C (002), I _C (100), I _C 101, I _C 102, I _C 110, and I _C 103, respectively. In the width direction, the peak intensities of the X-ray diffractions of the respective surfaces at the ends are respectively set to I _E (002), I _E (100), I _E (101), I _E 102, and I _E (110). , I _E (103). And when the bottom peak ratios (O _C , O _E ) in each of the center portion and the end portion are represented by the following equation, the ratio ( _{E E} / O _C ) of the bottom peak ratio of the end portion and the center portion is 0.89 ≦ O. Satisfies _E / O _C ≤1.15.

Bottom Peak Ratio O _C : I _C (002) / {I _C (100) + I _C (002) + I _C (101) + I _C (102) + I _C (110) + I _C (103)}

Bottom peak ratio O _E : I _E (002) / {I _E (100) + I _E (002) + I _E (101) + I _E (102) + I _E (110) + I _E (103)}

According to the Mg alloy rolled material of the present invention, the ratio (O _E / O _C ) of the bottom surface peak ratio of the end portion and the center portion of the Mg alloy rolled material satisfies the above range, whereby the orientation of the crystal surface is uniform in the width direction. Therefore, the rolling workability (formability) of Mg alloy rolling material can be made into a rolling material with a uniform width direction. Therefore, when plastic-working on this rolling material, even if it processes any part, a substantially uniform process can be performed.

As one aspect of the rolling material of the present invention, in the center portion and the end portion, when the average grain size in the cross section orthogonal to the rolling direction is D _C and D _E , respectively, the average grain size ratio (D _E) / D _C ) satisfies 0.7 ≦ D _E / D _C ≦ 1.5.

According to the said structure, since the average grain size ratio (D _E / D _C ) of the edge part and center part of Mg alloy rolling material satisfy | fills the said range, an average grain size is uniform in the width direction. Therefore, it can be set as the rolling material which is substantially uniform in strength and corrosion resistance in the width direction.

As one form of the rolling material of this invention, when extending | stretching in the tension test of a rolling direction is E _C and E _E in the said center part and an edge part, the draw ratio (E _E / E _C ) of the said end part and a center part is 2 / 3≤E _E / E _C ≤3 / 2.

According to the said structure, extending | stretching in a rolling direction is uniform in the width direction because the extending | stretching ratio (E _E / E _C ) of the edge part and center part of Mg alloy rolling material satisfy | fills the said range. That is, even if plastic working is performed in any place, a substantially uniform working can be performed.

As one form of the rolling material of this invention, when the tensile strength in the tension test of a rolling direction is set to Ts _C and Ts _E in the said center part and the edge part, the tensile strength ratio (Ts _E / Ts) of the said end part and the center part, respectively _C) a include those satisfying the 0.9≤Ts _E / Ts _C ≤1.1.

According to the said structure, since the tensile strength ratio (Ts _E / Ts _C ) of the edge part and center part of Mg alloy rolling material satisfy | fills the said range, tensile strength in a rolling direction is substantially uniform in the width direction.

As one aspect of the rolling material of the present invention, in the center portion and the end portion, when the 0.2% yield strength in the tensile test in the rolling direction is set to Ps _C and Ps _E , respectively, the 0.2% yield ratio (Ps _E of the end portion and the center portion). / _C Ps) are it includes those satisfying the 0.9≤Ps _E / Ps _C ≤1.1.

According to the said structure, since the 0.2% yield ratio (Ps _E / Ps _C ) of the said edge part and center part of Mg alloy rolling material satisfy | fills the said range, the said yield ratio in a rolling direction is uniform in the width direction. Therefore, the moldability in a rolling direction can be made into the rolling material which is substantially uniform in the width direction.

As one form of the rolling material of this invention, the said magnesium alloy raw material contains 5 mass% or more and 12 mass% or less of aluminum.

According to the said structure, by containing aluminum in the said range, it can be set as the Mg alloy rolling material excellent in corrosion resistance of higher hardness.

The Mg alloy member of the present invention is produced by subjecting the Mg alloy rolled material of the present invention to plastic working.

According to the said structure, since plastic working is given to the Mg alloy rolled material with a uniform mechanical characteristic in the width direction, it can be set as the Mg alloy member with a uniform characteristic in any place.

The manufacturing method of the Mg alloy rolling material of this invention is a method of rolling and manufacturing a magnesium alloy material with a rolling roll. The magnesium alloy material has a width of 1000 mm or more, and the rolling roll has three or more regions in the width direction. And temperature control is performed for every area | region so that the difference of the maximum temperature and minimum temperature in the width direction of the said rolling roll surface may be 10 degrees C or less.

According to the manufacturing method of this invention, the fluctuation | variation of the rolling state of the width direction can be reduced by making the temperature difference of the whole width direction of a rolling roll small. Therefore, rolling can be performed uniformly in the width direction with respect to the wide Mg alloy material whose width is 1000 mm or more. Therefore, there is little variation in thickness, edge cracking, etc., and can manufacture Mg alloy rolling material whose width is 1000 mm or more, and whose mechanical characteristic is substantially uniform in the width direction.

As one aspect of the manufacturing method of this invention, the said temperature control is what introduces and performs the fruit oil which adjusted the temperature in the said rolling roll.

According to the said structure, by using a heat oil for temperature control, it can control to the temperature set quickly from the inside of a rolling roll for each said area | region.

As one aspect of the manufacturing method of this invention, the said temperature control is performed by attaching the heating fluid which adjusted temperature to the said rolling roll surface.

According to the said structure, since a heating fluid adheres directly to a roll surface and temperature control, it can control precisely in the width direction of a rolling roll, such as each area | region and the location over each area | region. In addition, it is not necessary to insert the temperature control mechanism inside the rolling roll. That is, even with the existing rolling roll which does not have a temperature control mechanism by use of a heating fluid, the surface temperature can be easily controlled for every area | region from the outside of a roll.

As one aspect of the manufacturing method of this invention, the said temperature control is performed in the said rolling roll surface so that the temperature difference of two points | pieces which separated 100 mm in the width direction may be 6 degrees C or less.

According to the said structure, it is easy to control the fluctuation | variation of the temperature distribution of the whole width direction of a rolling roll by reducing the temperature difference of two adjacent points. Therefore, the variation of the rolling state in the width direction of the Mg alloy material can be reduced.

As one aspect of the production method of the present invention, preheating is performed such that the difference between the maximum temperature and the minimum temperature in the width direction of the surface of the magnesium alloy material immediately before passing through the rolling roll is 8 ° C. or less.

According to the said structure, by making small the temperature difference of the whole width direction of Mg alloy material, the fluctuation | variation of the rolling state in the width direction of Mg alloy material can be reduced more effectively. That is, not only a rolling roll but also the temperature of a raw material can reduce uniformity to a width direction, and can perform uniform rolling.

As one aspect of the manufacturing method of this invention, in the surface of the said magnesium alloy raw material just before passing through the said rolling roll, it pre-heats so that the temperature difference of 2 points | pieces separated by 100 mm in the width direction may be 6 degrees C or less, and the said temperature Control is performed so that the temperature difference of two points | pieces which separated 100 mm in the width direction on the surface of the said magnesium alloy rolling material immediately after passing the said rolling roll may be 6 degrees C or less.

According to the said structure, it is easy to control the fluctuation | variation of the temperature distribution of the whole width direction of a rolling roll further by reducing the temperature difference of two adjacent points before and behind rolling. Therefore, the fluctuation | variation of the rolling state in the width direction of Mg alloy material can be reduced more effectively.

The Mg alloy rolled material of the present invention has a wide width and uniform mechanical properties in the width direction.

The Mg alloy member of this invention can make a characteristic uniform in any location.

Even if the manufacturing method of the Mg alloy rolled material of this invention is a wide Mg alloy material whose width is 1000 mm or more, a rolled material with a uniform mechanical characteristic in a width direction can be manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram of the manufacturing process of the Mg alloy rolling material which concerns on embodiment, (A) is explanatory drawing which shows an example of a rolling line typically, (B) of the heat box used for the preheating of Mg alloy material. It is explanatory drawing.

Hereinafter, embodiments of the present invention will be described. First, an Mg alloy rolling material is demonstrated, and the manufacturing method is demonstrated with reference to FIG. 1 suitably.

<< Mg alloy rolled material >>

[Furtherance]

The Mg alloy rolled material has Mg element as a main component, and the thing (remainder: unavoidable impurity) of the various composition which contains the additive element in Mg is mentioned. Especially in this invention, it is preferable to set it as the Mg-Al type alloy which contains at least aluminum (Al) in an additional element. As the content of Al increases, the corrosion resistance is excellent, and mechanical properties such as strength and plastic deformation are also excellent. Therefore, in this invention, it is preferable to contain 3 mass% or more of Al, 5 mass% or more, especially 7.0 mass% or more is more preferable, and it is still more preferable if it contains 7.3 mass% or more. However, since the content of Al exceeds 12 mass%, the plastic workability will be reduced, so the upper limit is 12 mass%. As for content of Al, 11 mass% or less is especially preferable, and 8.3 mass%-9.5 mass% are preferable.

Additional elements other than Al include zinc (Zn), manganese (Mn), silicon (Si), beryllium (Be), calcium (Ca), strontium (Sr), yttrium (Y), copper (Cu), and silver (Ag). ), Tin (Sn), nickel (Ni), gold (Au), lithium (Li), zirconium (Zr), cerium (Ce) and rare earth elements (RE) (except Y, Ce) An element is mentioned. When it contains such an element, the content is 0.01 mass% or more and 10 mass% or less in total, Preferably 0.1 mass% or more and 5 mass% or less are mentioned. Of these additional elements, at least one element selected from Si, Sn, Y, Ce, Ca, and rare earth elements (except Y, Ce) is at least 0.001 mass% in total, preferably at least 0.1 mass% in total 5 When it contains mass% or less, it is excellent in heat resistance and flame retardance. In the case of containing a rare earth element, the total content thereof is preferably 0.1% by mass or more, and particularly, in the case of containing Y, the content thereof is preferably 0.5% by mass or more. The impurities include, for example, Fe.

More specific compositions of the Mg-Al-based alloys include, for example, AZ-based alloys (Mg-Al-Zn-based alloys, Zn: 0.2% by mass to 1.5% by mass) and AM-based alloys (Mg-Al-Mn-based alloys) in the ASTM standard. , Mn: 0.15 mass% to 0.5 mass%), Mg-Al-RE (rare earth element) alloy, AX alloy (Mg-Al-Ca alloy, Ca: 0.2 mass% to 6.0 mass%), AJ alloy (Mg-Al-Sr type alloy, Sr: 0.2 mass%-7.0 mass%) etc. are mentioned. In particular, Mg-Al-based alloys containing 8.3 mass% to 9.5 mass% of Al and 0.5 mass% to 1.5 mass% of Zn, typically the AZ91 alloy, are preferred because of their excellent corrosion resistance and mechanical properties.

[size]

If the width | variety of Mg alloy rolling material is 1000 mm or more, length and thickness should just be selected suitably according to the magnitude | size of the Mg alloy member to manufacture, It does not specifically limit. For example, the short material which cut | disconnected the elongate material and coil material to an appropriate length, etc. are mentioned. It is preferable that the rolling material which has any length is substantially uniform in thickness in the width direction. In particular, in the center part and the end part of the width direction of Mg alloy rolling material, when each thickness is t _C and t _E , the ratio of thickness (t _E / t _C ) is 0.97≤t _E / t _C ≤1.03 It is desirable to be satisfied. By satisfy | filling this range, when winding a Mg alloy rolled material with a coil, since thickness is uniform in the width direction, winding off shift | deviation can be reduced. The center part here is in the range of about 50 mm or less in both edge directions from the center of the width direction of a rolling material, and the end part is in the vicinity of the point within about 100 mm, preferably 50 mm or less in the center direction from an edge. . Thereafter, the center part and the end part show the same position as the center part and end part here.

[Mechanical Properties]

Even if the width | variety is 1000 mm or more in the Mg alloy rolling material of this invention, the following physical quantities can be made uniform over the whole width direction by making the rolling state of the width direction uniform as mentioned later. Specific mechanical properties are described below.

(Bottom peak ratio)

A bottom peak ratio is calculated | required by X-ray diffraction with respect to the center part and the edge part of the width direction of Mg alloy rolling material. The bottom peak ratio (O _C ) at the center part here is X-ray diffraction at (002) plane, (100) plane, (101) plane, (102) plane, (110) plane, and (103) plane. From the obtained peak intensities I _C (002), I _C (100), I _C (101), I _C (102), I _C (110), and I _C (103), I _C (002) / {I _C ( 100) + I _C (002) + I _C (101) + I _C (102) + I _C (110) + I _C (103)}. Similarly, the bottom peak ratio O _E at the end is determined by X-ray diffraction at the (002) plane, the (100) plane, the (101) plane, the (102) plane, the (110) plane, and the (103) plane. From the obtained peak intensities I _E (002), I _E (100), I _E (101), I _E (102), I _E (110), and I _E (103), I _E (002) / {I _E (100) + I _E (002) + I _E (101) + I _E (102) + I _E (110) + I _E (103)}. When the ratio (O _E / O _C ) of the bottom face peak ratio obtained in this way satisfies 0.89? O _E / O _C ? Such Mg alloy rolled material may have uniformity in orientation of the crystal plane in the width direction of the Mg alloy rolled material, and may have substantially uniform plastic workability (formability) in the width direction. Regarding the point where these X-ray diffractions are measured, it measures on the surface in the said center part and the edge part, respectively.

(Average grain size)

In the said center part and the edge part, the average grain size in the cross section orthogonal to a rolling direction is calculated | required based on "microscope test method JIS G 0551 (2005) of an iron-crystal grain size," respectively. And, when the average grain diameter of the central portion and the end _C to D, D and _E, respectively, said end portion to the average grain guard (D _E / D _C) of the central portion satisfies the 0.7≤D _E / D _C ≤1.5, average The particle diameter is assumed to be substantially uniform in the width direction. If it is such an Mg alloy rolling material, intensity | strength and corrosion resistance can be made substantially uniform in the width direction. As for this average grain size ratio (D _E / D _C ), it is more preferable that 0.9 <= D _E / D _{C <} 1.1.

(Stretching, tensile strength, 0.2% yield strength)

Drawing, tensile strength, and 0.2% yield strength are calculated | required based on "the metallic material tensile test method JIS Z 2241 (1998)" in each of the said center part and the edge part. This tension test cuts JIS 13B test piece (JIS Z 2201 (1998)) so that a long side may follow a rolling direction in each of the said center part and the edge part, and it is performed with respect to the test piece.

And when extending | stretching of a center part and an edge part is E _C and E _E , respectively, and when the draw ratio (E _E / E _C ) of the said end part and a center part satisfies 2/3 < _{E E} / E _{C <} 3/2, the width direction Stretching is made to be substantially uniform.

Similarly, a tensile strength substantially when the tensile strength in each Ts _C, Ts _E, and the end portion and the tensile strength ratio (Ts _E / Ts _C) of the central portion satisfies the 0.9≤Ts _E / Ts _C ≤1.1, the transverse direction It shall be uniform.

Further, when the 0.2% proof stress in each _C Ps, Ps _E, and the end and the 0.2% proof stress ratio (Ps _E / Ps _C) of the central portion satisfies the _{0.9≤Ps E / Ps C ≤1.1, 0.2} % in the transverse direction The load capacity is assumed to be substantially uniform.

When these stretching, tensile strength, and 0.2% yield strength satisfy | fill the said range, moldability can be made uniform in the width direction.

<Magnesium alloy member>

By performing plastic working on the Mg alloy rolled material of this invention, an Mg alloy member is obtained. As the plastic working, various processing such as press working, deep drawing processing, forging processing and bending processing can be adopted. As the Mg alloy member subjected to such plastic working, representatively, plastic working is performed on the whole thereof, for example, only a part of a three-dimensional plastic working member such as a cylindrical member or a wavy member, or a part of the Mg alloy rolled material is fired. It also includes the form which processed, ie, the form which has a plastic processing part. Since the Mg alloy rolled material of this invention is uniform in mechanical width in the width direction, since the location to plastic-work is not restrict | limited, it can select suitably and can perform plastic working, such as bending, freely. When plastic working is performed by heating the said rolled material to 200 degreeC-300 degreeC, a crack etc. do not produce easily and the Mg alloy member excellent in the surface property is obtained. In addition, as described above, the Mg alloy rolled material having a uniform mechanical property in the width direction makes the properties uniform at any place of the Mg alloy member.

In addition, it can be set as the plate-shaped Mg alloy member of a predetermined shape by giving the Mg alloy rolling material of this invention various processes which change shapes, such as cutting and punching, suitably.

The obtained Mg alloy member is subjected to surface property modification treatment such as polishing, anticorrosive treatment such as chemical conversion treatment, anodization treatment, and decorative surface treatment such as painting to further improve corrosion resistance, achieve mechanical protection, or improve product value. You can raise or do it.

<< Manufacturing method of Mg alloy rolled material >>

The Mg alloy rolled material whose width mentioned above is 1000 mm or more and whose mechanical property is uniform in a width direction is manufactured by rolling a Mg alloy material with a rolling roll. As shown in FIG. 1 (A), this rolling rolls the Mg alloy material sheet 1 fed from one reel 10a, 10b with a rolling roll 3, and the rolled material sheet. A plurality of passes are performed by winding (1) in the other reels 10b and 10a as one pass. Here, reverse rolling which reverses the rotation direction of each reel 10a, 10b is performed every one pass. The protective cover 5 is arrange | positioned in the middle of the reels 10a and 10b and the rolling roll 3 so that the surface temperature of the Mg alloy material sheet 1 may not fall before and behind a rolling roll. And the temperature sensor 4r, 4bf, 4bb which measures the surface temperature of the raw material plate 1 just before passing through the rolling roll 3 and the rolling roll 3 is provided. The characteristic of the manufacturing method of this invention is that a rolling roll has three or more area | regions in the width direction, and temperature control for every area | region so that the difference of the maximum temperature and minimum temperature in the width direction of the rolling roll surface may be 10 degrees C or less. In this way, the Mg alloy rolled material of the present invention can be obtained. This method is described in detail below.

[Preparation of Mg Alloy Material]

(casting)

First, the Mg alloy material sheet 1 is prepared. As the Mg alloy material sheet 1, a casting material (cast plate) having the same composition as that of the rolling material described above can be suitably used. Casting materials are manufactured by continuous casting methods, such as a twin roll casting method, die casting, etc., for example. In particular, since the twin roll casting method enables rapid solidification, internal defects such as oxides and segregates can be reduced, and the occurrence of cracks and the like can be reduced when these internal defects originate during plastic working such as rolling. That is, the twin roll casting method is preferable because the casting material excellent in rolling property is obtained. In particular, Mg alloy materials containing a large amount of Al tend to cause crystallization and segregation during casting, and crystallization and segregation are likely to remain inside even after a casting or the like process. Since segregation etc. can be reduced as mentioned above, it can utilize suitably for Mg alloy materials. Although the thickness of a casting material is not specifically limited, Since it is easy to produce segregation when it is too thick, 10 mm or less, Furthermore, 5 mm or less, Especially 4 mm or less are preferable. The width of the cast material is at least 1000 mm. Casting materials of a width that can be manufactured in a manufacturing facility can be used. In this example, the cast elongate cast material is wound into a coil shape to form a cast coil material, which is then provided to the next step. At the time of winding, especially in the casting material, when the temperature of the start of winding is about 100 ° C. to 200 ° C., even an alloy species such as AZ91 alloy, which tends to be cracked, is easily bent and wound up.

(Solubilization)

Although the said casting material may be rolled, you may make the molten material obtained by performing the solution treatment on the casting material before rolling as the Mg alloy material board 1. The solution treatment allows homogenization of the cast material. As for the conditions of a solution treatment, holding temperature: 350 degreeC or more, Preferably 380 degreeC-420 degreeC, holding time: 30 minutes-2400 minutes are mentioned. It is preferable that the holding time is made longer as the content of Al is higher. In the cooling step from the holding time, when the cooling rate is increased by using forced cooling such as water cooling or air blowing, precipitation of coarse precipitates can be suppressed and the sheet material can be excellent in rollability. When the solution treatment is performed on a long casting material, the casting material can be efficiently heated when the casting material is wound in a coil shape like the casting coil material.

[Preheat]

The cast material or the Mg alloy material subjected to the solution treatment is rolled to produce an Mg alloy rolled material having desired mechanical properties. In rolling, in addition to improving plastic workability (rollability) of an Mg alloy material, you may preheat, in order not to produce the fluctuation | variation of a rolling state in the width direction. When preheating, for example, using a heating means such as the heat box 2 shown in Fig. 1B, the elongated Mg alloy material sheet 1 can be heated at once, and the workability is excellent. The heat box 2 is a hermetically sealed container capable of storing the coiled Mg alloy material sheet 1, and an atmosphere in which hot air of a predetermined temperature is circulated and supplied into this container to maintain the inside of the container at a desired temperature. It is ro. In particular, when the Mg alloy material sheet 1 is taken out from the heat box 2 and rolled as it is, the time until the heated Mg alloy material sheet 1 contacts the rolling roll 3 is measured. It can shorten and it can suppress effectively that the temperature of the Mg alloy material sheet 1 falls until it contacts the rolling roll 3. Specifically, the heat box 2 can accommodate the coiled Mg alloy material sheet 1 and rotatably rotates the reel 10 that can feed and wind the Mg alloy material sheet 1. The supporting structure is mentioned. The Mg alloy material plate 1 is accommodated in this heat box 2, and it heats to specific temperature. 1B shows a state in which the Mg alloy material sheet 1 wound in a coil shape is housed in the heat box 2, and is actually closed and used, but the front surface is opened for easy understanding. The state is shown.

In a preheating process, it heats so that the temperature of a Mg alloy material may be 300 degrees C or less. The set temperature of heating means, such as a heat box, can be selected in the range of 300 degrees C or less, In particular, just before rolling, set temperature so that the surface temperature of a raw material may be in the range of 150 degreeC-280 degreeC over all the passes. It is desirable to adjust. Here, when a multipass rolling is performed to Mg alloy material, there exists a tendency for the temperature of Mg alloy material to rise by processing heat. On the other hand, the temperature of Mg alloy material may fall until it loosens an Mg alloy material and contacts a rolling roll. Therefore, it is preferable to adjust the set temperature of the heating means in consideration of the rolling speed (mainly the running speed of the raw material in rolling), the distance from the heating means to the rolling roll, the temperature of the rolling roll, the number of passes, and the like. As for the preset temperature of a heating means, 150 degreeC-280 degreeC is preferable, Especially 200 degreeC or more, Especially 230 degreeC-280 degreeC is easy to use. The heating time is sufficient until the Mg alloy material can be heated to a predetermined temperature. However, in the Mg alloy coil material wound in a coil shape, the temperature fluctuations in the inner region and the outer region of the coil are reduced, so that the entire Mg alloy coil member It is preferable to employ | adopt sufficient time so that it may become a uniform temperature. In addition, what is necessary is just to set heating time suitably according to the weight of a coil, a magnitude | size (width, thickness), winding number, etc.

Before passing through the rolling roll 3, covering the raw material sheet 1 with the protective cover 5 made of a heat insulating material so that the surface temperature of the preheated and extracted Mg alloy raw material sheet 1 does not fluctuate in the width direction. desirable. In particular, since the heating state of the both ends of the width direction of the raw material board 1 is hard to be maintained, and it is easy to cool, it is preferable to cover at least both ends so that the temperature of the width direction may not fluctuate. By doing so, subsequent rolling becomes easy to be performed uniformly in the width direction, and fluctuations are less likely to occur in the rolling state.

The surface temperature of the Mg alloy material sheet 1 is measured before and after passing the rolling roll 3. A temperature sensor for this purpose is arranged between the rolling roll 3 and each of the reels 10a and 10b. For example, in FIG. 1A, when the direction in which the raw material sheet 1 travels from the left side of the paper to the right side is a path direction, the temperature sensor 4bf disposed on the left side of the rolling roll 3 ) Detects the surface temperature of the Mg alloy material sheet 1 immediately before passing through the rolling roll 3, and the temperature sensor 4bb disposed on the right side of the rolling roll 3 passes through the rolling roll 3 The surface temperature of the rolling plate immediately after it is detected. On the other hand, when the direction in which the raw material sheet 1 travels from the right side of the paper to the left side is the return direction, the temperature sensor 4bf disposed on the right side of the rolling roll 3 passes through the rolling roll 3. The surface temperature of the Mg alloy material sheet 1 immediately before is detected, and the surface temperature of the rolled plate immediately after the temperature sensor 4bb disposed on the left side of the rolling roll 3 passes through the rolling roll 3 is detected. do.

The surface temperature of the Mg alloy material sheet 1 preheated in the above temperature range is measured by a temperature sensor 4bf before rolling. The type of the temperature sensor 4bf may be a contact sensor that is in contact with the raw plate 1 and measured, but a non-contact sensor is preferable in order not to damage the raw plate 1. What is necessary is just to select suitably the number and arrangement place of this temperature sensor 4bf so that the center part of the width direction of the raw material board 1, and three places of both ends can be measured individually. For example, three temperature sensors 4bf are arrange | positioned at the center part and both ends, respectively, and it is mentioned to measure each temperature. As will be described later, in the case of controlling the temperature difference for every 100 mm interval in the width direction of the raw material sheet 1 (rolled sheet), a number of temperature sensors corresponding to the plate width may be provided every 100 mm. And based on the temperature measured by this sensor 4bf, it is preferable to perform control, such as changing the heating temperature of the said preheating heating and auxiliary heating means, such as a heat generating lamp mentioned later. By doing so, the temperature difference of the whole width direction of the Mg alloy material sheet 1 is easy to be reduced.

It is preferable to arrange auxiliary heating means (not shown) for reheating the Mg alloy material sheet 1 based on the measured temperature of the temperature sensor 4bf. A heating lamp etc. are mentioned as this auxiliary heating means, and are arrange | positioned rather than the temperature sensor 4bf on the reel 10a, 10b side. What is necessary is just to select the number which arrange | positions this auxiliary heating means suitably so that at least two places of both ends may be individually heated in the width direction of the Mg alloy material board 1. By doing so, temperature control of both ends which are hard to maintain a heated state by rolling, that is, easy to cool can be performed individually, and the fluctuation | variation of temperature in the width direction can be reduced.

By preheating including this reheating, the difference between the highest temperature and the lowest temperature in the entire width direction of the Mg alloy material sheet 1 is 8 ° C. or less, in particular 5 ° C. or less, within the set temperature. It is desirable to control the temperature as much as possible. By doing so, even if the width | variety of the Mg alloy material board 1 etc. which are 1000 mm or more in width is small in the fluctuation | variation of the temperature of the whole width direction, a change does not produce easily in the rolling state of the Mg alloy material board 1. In addition, it is preferable that the temperature difference between two points 100 mm apart in the width direction of the Mg alloy material sheet 1 is 6 ° C or less and 3 ° C or less. By reducing the temperature difference between two adjacent points, it is easy to control the fluctuation of the temperature distribution of the whole width direction of the Mg alloy material sheet 1, and as a result, the fluctuation of the rolling state of the Mg alloy material sheet 1 is reduced more effectively. can do.

[Rolling]

The Mg alloy material sheet 1 heated by the heating means like the heat box 2 is taken out from the heat box 2, and is supplied to the rolling roll 3 to perform rolling. Specifically, for example, building a rolling line as shown in Fig. 1A is mentioned. The rolling line is disposed between the reversible pair of reels 10a and 10b and the pair of reels 10a and 10b spaced apart from each other so as to be opposed to each other so as to sandwich the traveling Mg alloy material sheet 1. A pair of rolling rolls 3 is provided. The coil-shaped Mg alloy material sheet 1 is attached to one reel 10a and unwound, and one end of the Mg alloy material sheet 1 is wound by the other reel 10b, thereby obtaining the Mg alloy material sheet 1. Travels between both reels 10a and 10b. During this run, the Mg alloy material sheet 1 can be rolled by being sandwiched between the rolling rolls 3. In the example shown to FIG. 1A, each reel 10a, 10b is accommodated in the heat box 2a, 2b, respectively, and the Mg alloy material board 1 wound up in each reel 10a, 10b. Is heatable by each heat box 2a, 2b. Then, the heated Mg alloy material sheet 1 is unwound from one reel, discharged from one heat box, traveling toward the other heat box, and wound up on the other reel.

Here, both ends of the Mg alloy material sheet 1 are respectively wound on the reels 10a and 10b, and an intermediate region excluding the both end side regions wound on the reels 10a and 10b is introduced into the rolling roll 3 , Multiple passes are rolled. Rolling of each pass is performed by reversing the rotation directions of the reels 10a and 10b every one pass. That is, reverse rolling is performed. Therefore, the Mg alloy material sheet 1 is not removed from the reels 10a and 10b until the final pass.

In addition, in FIG. 1, the number of the rolling rolls 3 is an illustration, It can be set as the structure which arrange | positioned several pairs of rolling rolls in the running direction of the Mg alloy material sheet 1. As shown in FIG.

And the rolling roll 3 is heated so that surface temperature may become 230 degreeC-290 degreeC specifically ,. By setting it as 230 degreeC or more, since the raw material plate 1 can be kept in a fully heated state, a raw material plate can be made into the state excellent in plastic workability, and rolling can be performed favorably. By setting it as 290 degrees C or less, release of the process distortion introduced by coarsening of the grain size of the raw material plate 1 and rolling can be suppressed, and the rolled sheet excellent in press formability can be manufactured.

Within the range of the said temperature, temperature control is carried out so that the difference of the maximum temperature and minimum temperature in the width direction of a rolling roll surface may be 10 degrees C or less. The fluctuation | variation of the rolling state of the width direction can be reduced by making the temperature difference of the whole width direction of the rolling roll 3 small. That is, the mechanical properties of the Mg alloy rolled material can be made uniform in the width direction. In addition, it is possible to effectively reduce the occurrence of fluctuations in the thickness of the rolled plate and the phenomenon of unwinding due to the variation in the thickness. As for the difference of the highest temperature and the minimum temperature in the width direction of this rolling roll 3, it is more preferable to set it as 5 degrees C or less.

Moreover, it is preferable to perform temperature control so that the temperature difference of two points | pieces separated by 100 mm in the width direction of the rolling roll 3 may be 6 degrees C or less, and 3 degrees C or less. By reducing the temperature difference between two adjacent points, it is easy to control the variation of the temperature distribution of the whole rolling direction of the rolling roll 3, and as a result, the variation of the rolling state of the Mg alloy material sheet 1 can be reduced more effectively. have. Although the distance of these two points may be 100 mm or more, or less, it is preferable, so that it is easy to control the temperature fluctuation of the whole width direction as it is short.

The temperature of the rolling roll 3 can be confirmed by the temperature sensor 4r. This temperature sensor 4r may also be a contact type sensor which contacts and measures the roll 3, and a non-contact type sensor may be sufficient as it. What is necessary is just to select the number and position which arrange | position the temperature sensor 4r so that at least 3 center part and the both ends of the width direction of the roll 3 can be measured. For example, the three temperature sensors 4r are arrange | positioned at the center part and both ends, respectively, and the thing which measures each temperature is mentioned. What is necessary is just to provide the temperature sensor of the number according to the rolling roll width every 100 mm, in the case of controlling a temperature difference for every 100 mm interval in the width direction of the rolling roll 3.

In addition, the temperature of the raw material plate 1 immediately after passing through the rolling roll 3 is also confirmed by the temperature sensor 4bb. It is preferable to perform temperature control, such as changing the heating temperature of the rolling roll 3 suitably based on the temperature measured by the temperature sensor 4bb. By doing so, the temperature difference of the whole width direction of the Mg alloy material sheet 1 can be reduced more easily. By the measurement of this temperature sensor 4bb, it is preferable if the temperature difference of two points | pieces which separated 100 mm in the width direction of the Mg alloy material board 1 is 6 degrees C or less, and it is especially preferable if it is 3 degrees C or less.

In addition, since the whole of the raw material sheet 1 wound by the coil shape has a large heat capacity compared with the unwound part, it is considered that temperature is hard to fall comparatively at the time of the said conveyance or installation. On the other hand, after feeding out from the reel 10 or a supply apparatus, there exists a possibility that the temperature fall until it may contact the rolling roll 3 may become comparatively large. As a reason for this, it is conceivable that it is easy to cool because it is a part of the material as described above and the heat capacity is small, or the magnesium alloy is a metal having excellent thermal conductivity. The degree of decrease in the temperature of the raw material sheet 1 until it comes in contact with the rolling roll 3 is influenced by the thickness of the raw material sheet 1, the traveling speed of the raw material sheet 1, and the like. The slower the rate, the easier the temperature is to fall. Before the surface temperature of the raw material sheet 1 becomes lower than 170 degreeC, it is preferable to supply to the rolling roll 3 at 180 degreeC or more, especially 210 degreeC or more. Moreover, what is necessary is just to adjust the rotation speed (circle speed) of a rolling roll suitably according to the traveling speed of a raw material, and rolling can be performed efficiently as it is 5 m / min-200 m / min, for example.

In order to control the temperature of the surface of the rolling roll 3 as mentioned above, the rolling roll 3 has three or more area | regions in the width direction, and temperature-controls for every area | region. As a means thereof, for example, a heater such as a cartridge heater is incorporated (heater type), a liquid such as heated oil (solvent oil) or the like is introduced into the rolling roll or circulated in the roll (liquid circulation type), or the temperature is adjusted. Direct attachment of one heating fluid. As a specific means of directly attaching a heating fluid to the rolling roll 3, spraying gas, such as a hot air (hot air type), and apply | coating the lubricant etc. which are mentioned later are mentioned. In particular, when the heated oil is circulated inside the rolling rolls 3 and the rolls are heated, the heating liquid can be filled in the rolling rolls 3 in the width direction and the circumferential direction. The temperature can be controlled at a predetermined temperature promptly from the inside of the rolling roll 3 for each region, and it is easy to suppress the difference between the maximum temperature and the minimum temperature in the width direction of the roll in the above-described range. Although the temperature of the liquid to circulate depends on the magnitude | size (width, diameter) of a rolling roll 3, a material, and the width | variety or position of the said area | region, the set surface temperature of the rolling roll 3 + about 10 degreeC is preferable. The liquid circulation mechanism used for water-cooled copper etc. can be applied to circulation of the said liquid, for example. In addition, in order to reduce the temperature fluctuation of the width direction of the rolling roll 3, it is preferable to adjust and accommodate several heater for every said area in a heater type | mold. That is, it is preferable to change the number of heaters accommodated in the roll center part which a heating state is easy to maintain, and the edge part which is hard to maintain a heating state, or to change the temperature of a heater. A sliding contact may be used for electrical connection between the heater side and the power supply side in the rotating shaft of the rolling roll 3. In the hot air type, adjusting the temperature of the gas, the injection amount, the number of jets, the arrangement position of the jets, and the like can be mentioned.

In the rolling of each pass, the reduction ratio per pass can be appropriately selected. The reduction ratio per pass is preferably 10% or more and 40% or less, and the total reduction ratio is preferably 75% or more and 85% or less. By performing roll rolling a plurality of times (multipass) to the material at such a reduction ratio, the desired sheet thickness, the average grain size can be reduced, the press workability can be increased, and the occurrence of defects such as surface cracks can be suppressed. Can be.

In rolling, when a lubricant is used, friction between a rolling roll and a raw material can be reduced, and rolling can be performed favorably. What is necessary is just to apply a lubricant to a rolling roll suitably. However, depending on the type of lubricant, it has been found that the lubricant remaining in the raw material may be squeezed out by heating in the next preheating step or by contact with a rolling roll, resulting in a deteriorated layer. In addition, when such a deteriorated layer is present, the material is not uniformly rolled, and a variation occurs in the thickness, or due to the variation in the thickness, the raw material meanders or runs in one direction and runs (flows sideways), As a result, knowledge has been obtained that shifting and winding are likely to be large. Moreover, although the detailed mechanism is not clear, the knowledge that a lubricant is easy to remain | survive on both edge parts side rather than the center part of the width direction of a raw material was acquired. Therefore, in consideration of the maximum value of the heating temperature of a rolling roll: 290 degreeC and a space, it is preferable to use the thing in which a deterioration layer is not formed at about 300 degreeC. Moreover, in order to prevent the presence of a lubricant and a deterioration layer locally in a raw material as mentioned above, it is preferable to justify the lubricant of the surface of a raw material immediately before supplying a raw material to a rolling roll. For example, it arrange | positions a smoothing means, such as a brush and a wiper, on the upstream side of a rolling roll, and makes uniform the nonuniformity of the lubricant on the surface of a raw material.

In order to adjust the tension applied to the raw material sheet 1 at the time of rolling, a pinch roll (not shown) can be arrange | positioned before and behind the rolling roll 3. In order to prevent the temperature fall of the raw material by contact with a pinch roll, it is preferable to heat a pinch roll about 200 degreeC-250 degreeC.

(Winding)

The rolled plate obtained by performing the said rolling is wound up in coil form. Then, the preheating step, the rolling step, and the series of steps including the winding step are successively repeated, and after rolling the desired number of times, the obtained rolled plate (magnesium alloy plate) is finally wound into a coil shape. The magnesium alloy plate which comprises the obtained coil material has the structure which the processing distortion (shear stage) introduce | transduced by rolling exists. By having such a structure, the said magnesium alloy plate produces | generates dynamic recrystallization at the time of plastic working like press work, and is excellent in plastic workability. In particular, in the rolling of the final pass, when the temperature of the rolled sheet immediately before the winding is wound at a temperature not to be recrystallized, specifically, 150 ° C. or lower, a magnesium alloy sheet having excellent flatness is obtained, and the processing distortion remains sufficiently. You can do it with an organization. In order to set the temperature at which the rolled sheet immediately before the winding is not recrystallized, the running speed of the raw material may be adjusted. However, if the rolled sheet is cooled by forced cooling such as air blast, the temperature can be set in a short time and the workability is excellent.

(Calibration process)

The coiled coil material can be used as a product (typically a material of a magnesium alloy material such as a plastic working material) as it is. Moreover, this coil material can be unwound, a predetermined bending is given to a rolled board, and the process distortion introduced by rolling can be corrected. A roller leveler can be used suitably for straightening. The roller leveler is provided with at least one pair of opposing rollers, and imparts bending by inserting a raw material between the rollers. In particular, a plurality of rollers are arranged in a zigzag shape, and a rolled plate can be passed between these rollers, whereby repeated bending can be applied to the rolled plate. By performing such correction, a magnesium alloy sheet having even more flatness can be obtained, and since the processing distortion is sufficiently present, it is excellent in plastic workability such as press working. When the roller is provided with a heating means, for example, a heater, and is subjected to warm calibration to give bending to the rolled plate by the heated roller, cracks and the like are less likely to occur. The roller temperature is preferably 100 ° C or more and 300 ° C or less. Adjustment of the amount of bending provided by the calibration can be performed by adjusting the size, number of rollers, the gap (gap) between the rollers arranged oppositely, the distance between the rollers adjacent in the advancing direction of the raw material, and the like. Before performing the calibration, the magnesium alloy sheet (rolled sheet) serving as a raw material may be heated in advance. The specific heating temperature is not less than 100 ° C and not more than 250 ° C, preferably not less than 200 ° C.

The magnesium alloy plate subjected to the calibrating process can be used as it is as a product (typically, a magnesium alloy material such as a sintering material). Moreover, in order to make surface state favorable, you may perform surface grinding | polishing using a polishing belt etc.

&Lt; Action >

According to the Mg alloy rolling material which concerns on embodiment mentioned above, and the manufacturing method of an Mg alloy rolling material, the following effects are exhibited.

(1) It is a wide Mg alloy rolled material whose width is 1000 mm or more, and mechanical properties are substantially uniform in the width direction. Therefore, when plastic-working on this rolling material, even if it processes any part, a substantially uniform process can be performed.

(2) Since the mechanical properties are uniform in the width direction, even if a single rolled material is divided in the width direction and a plurality of narrow Mg alloy rolled sheets are produced, the rolled material having the same mechanical properties can be obtained.

(3) According to the manufacturing method mentioned above, even if the width | variety is 1000 mm or more by making small the temperature difference of the whole width direction of a rolling roll, the fluctuation | variation of the rolling state of the width direction can be reduced. Therefore, the Mg alloy rolled material whose width is 1000 mm or more and uniform mechanical property in the width direction can be manufactured.

<Test Example>

As a test example, the following Mg alloy rolling material is produced, and mechanical properties are examined. First, Mg alloy material sheet which is a composition equivalent to AZ91 containing Mg-9.0 mass% Al-1.0 mass% Zn and a composition equivalent to AZ31 containing Mg-3.0 mass% Al-1.0 mass% Zn by twin roll casting Mg alloy plate is produced. The plate | board thickness of these raw material boards is 5.0 mm, plate | board width is 1020 mm, and length is 1000 mm. Each of these samples is subjected to a solution treatment for 20 hours at 400 ° C. before rolling. Thereafter, rolling was performed under the conditions described below to prepare Samples 1 to 3 made of AZ91 and Samples 4 to 6 made of AZ31.

(Rolling conditions)

Multiple pass rolling reduction rate: 15-25% / pass

Final thickness: rolled to 1.0 mm (width: 1020 mm) Total pressure drop: 80%

Preheating of the material board (in the furnace, heating time: 30 minutes)

Heating method of rolling roll: Heating outside the roll

The heating method of a rolling roll was performed by dividing the width direction of a rolling roll equally into three area | regions, and apply | coating the lubricant which adjusted the temperature directly to those three area | regions. In the sample 1, the lubricant adjusted to 250 degreeC-255 degreeC was apply | coated to the center of three area | regions, and the lubricant adjusted to 255 degreeC-260 degreeC was applied to the both sides, and roll surface temperature was made uniform in the width direction. . On the other hand, in sample 4, the lubricant adjusted to 230 degreeC-235 degreeC was apply | coated to the said center, and the lubricant adjusted to 235 degreeC-240 degreeC was applied to the both sides, and roll surface temperature was made uniform in the width direction.

When rolling, the temperature of the surface of the Mg alloy raw material board immediately before rolling, the rolling roll surface, and the surface of the Mg alloy rolling board immediately after rolling was measured and calculated | required as follows. An arbitrary straight line is drawn along the width direction (direction parallel to the axial direction) of this roll in the area | region which a raw material plate contacts on the surface of a rolling roll, and the temperature of several points is measured on this straight line. Here, the arbitrary straight lines are drawn on the surfaces of the Mg alloy material sheet, the rolling roll, and the Mg alloy rolled material, and on this straight line, a point of 10 mm from one end in the width direction and 10 points at equal intervals of 100 mm from the point. A total of 11 points were taken and the temperature of each point was measured with a non-contact temperature sensor. In that case, the temperature of the width direction of a rolling roll measures the temperature of the place which deviated from the injection | pouring area of a lubricant among the surfaces of a rolling roll so that the temperature of lubricant itself may not be measured. These values are shown in Tables 1-3.

[Mechanical Characterization]

The following characteristics were evaluated about the samples 1-6 of the obtained Mg alloy rolling material.

[Base Peak Ratio]

The bottom peak ratio of Samples 1-6 was measured by the peak intensity of X-ray diffraction. This measurement is performed by X-ray diffraction with respect to the surface of 50 mm (end), 500 mm (center), and 950 mm (end) points from one end in the width direction of each sample, and the (002) plane, the (100) plane, ( The peak intensities of the 101 plane, the (102) plane, the (110) plane, and the (103) plane were obtained. From the results, the bottom peak ratios (O _E , O _C ) of the end and the center portion were obtained, respectively, and the ratio (O _E / O _C ) was also obtained. The bottom peak ratios (O _C , O _E ) represent the peak intensities of the X-ray diffractions of the respective surfaces at the center and the end, respectively, as follows: I _C (002), I _C (100), I _C (101), and I _C ( 102), I _C (110), I _C (103), I _E (002), I _E (100), I _E (101), I _E (102), I _E (110), I _E (103) When expressed as, the following equation is written.

Bottom Peak Ratio O _C : I _C (002) / {I _C (100) + I _C (002) + I _C (101) + I _C (102) + I _C (110) + I _C (103)}

Bottom peak ratio O _E : I _E (002) / {I _E (100) + I _E (002) + I _E (101) + I _E (102) + I _E (110) + I _E (103)}

The results are shown in Table 4.

[Average grain size]

The average grain size of Samples 1-6 was measured based on "microscope test method JIS G 0551 (2005) of iron-crystal grain size". This measurement was performed about the cross section orthogonal to a rolling direction at the point of 50 mm (end part), 510 mm (center part), and 970 mm (end part) from the width direction end of each sample. From the results, the average grain size ratio (D _E / D _C ) between the end portion and the center portion was obtained. The results are shown in Table 4.

[Tensile test]

The stretching, tensile strength, and 0.2% yield strength of Samples 1 to 6 were measured based on "Metal Material Tensile Testing Method JIS Z 2241 (1998)". At the time of this measurement, the JIS 13B test piece (JIS Z 2201 (1998)) is longer at the points of 50 mm (end), 510 mm (center), and 970 mm (end) from the width direction end of the sample. It cut out along a rolling direction, and the tension test was done about the test piece. From the results, the draw ratios (E _E / E _C ), the tensile strength ratios (Ts _E / Ts _C ), and the 0.2% yield strength ratios (Ps _E / Ps _C ) were obtained, respectively.

The above results are summarized in Table 5.

[result]

From the above result, when rolling the wide Mg alloy material whose width is 1000 mm or more, it turned out that the fluctuation | variation of the rolling state of the width direction can be reduced by reducing the temperature difference of the whole width direction of the rolling roll surface. In addition, it can be seen that by changing the temperature difference of the entire width direction of the surface of the Mg alloy material before rolling, the variation in the rolling state can be further reduced, and uniform rolling can be performed in the width direction of the Mg alloy material. there was. By reducing the variation in the rolling state in this manner, it was also found that an Mg alloy rolled material having a uniform mechanical characteristic in the width direction can be obtained.

In addition, the above-mentioned embodiment can be suitably changed without departing from the gist of the present invention, and is not limited to the above-described configuration.

The Mg alloy rolled material of the present invention is a member of various electrical and electronic devices, in particular, housings of portable and small electric and electronic devices, members of various fields requiring high strength, for example, materials of structural members of transport equipment such as automobiles and aircrafts. It can be used suitably. The manufacturing method of the Mg alloy rolled material of this invention can be used suitably for manufacture of the Mg alloy rolled material whose width is 1000 mm or more and a mechanical characteristic is uniform in a width direction.

1: Mg alloy plate 2, 2a, 2b: heat box
3: rolling roll 4bf, 4bb, 4r: temperature sensor
5: protective cover 10, 10a, 10b: reel

Claims (13)

In the magnesium alloy rolling material formed by rolling a magnesium alloy material with a rolling roll,
The width of the magnesium alloy rolled material is 1000 mm or more,
In the width direction of the said magnesium alloy rolling material,
The peak intensities of the X-ray diffraction of the (002) plane, the (100) plane, the (101) plane, the (102) plane, the (110) plane, and the (103) plane at the center are respectively set to I _C (002) and I _C ( 100), I _C 101, I _C 102, I _C 110, I _C 103,
The peak intensities of the X-ray diffractions of the respective surfaces at the ends are respectively I _E (002), I _E (100), I _E (101), I _E (102), I _E (110), and I _E (103). With
When the bottom peak ratios (O _C , O _E ) at each of the center and the end are given by the following equation,
Bottom Peak Ratio O _C : I _C (002) / {I _C (100) + I _C (002) + I _C (101) + I _C (102) + I _C (110) + I _C (103)}
Bottom peak ratio O _E : I _E (002) / {I _E (100) + I _E (002) + I _E (101) + I _E (102) + I _E (110) + I _E (103)}
The ratio (O _E / O _C ) of the bottom peak ratio of the end portion and the center portion satisfies 0.89≤O _E / O _C ≤1.15. The method according to claim 1, wherein the average grain size in the cross section orthogonal to the rolling direction at the center and the end is D _C and D _E , respectively.
Average grain guard (D _E / D _C) of the end portion and the central portion is a magnesium alloy rolled material, characterized by satisfying the 0.7≤D _E / D _C ≤1.5. The said central part and the edge part WHEREIN: When extending | stretching in the tension test of a rolling direction is E _C and E _E , respectively,
The draw ratio (E _E / E _C ) of the end portion and the center portion satisfies 2 / 3≤E _E / E _C ≤ 3/2. The said center part and the edge part WHEREIN: When the tensile strength in the tension test of a rolling direction is set to Ts _C and Ts _E , respectively, in any one of Claims 1-3,
The tensile strength of the non-end portion and the central portion (Ts _E / Ts _C) is a magnesium alloy rolled material, which satisfy the 0.9≤Ts _E / Ts _C ≤1.1. The 0.2% yield strength in the tension test of a rolling direction is set to Ps _C and Ps _E in any one of Claims 1-4, respectively.
The 0.2% yield ratio (Ps _E / Ps _C ) of the end portion and the center portion satisfies 0.9 ≦ Ps _E / Ps _C ≦ 1.1. The magnesium alloy rolled material according to any one of claims 1 to 5, wherein the magnesium alloy material contains 5% by mass to 12% by mass of aluminum. A magnesium alloy member produced by subjecting the magnesium alloy rolled material according to any one of claims 1 to 6 to plastic working. In the manufacturing method of the magnesium alloy rolled material in which the magnesium alloy material is rolled with a rolling roll to produce a magnesium alloy rolled material,
The magnesium alloy material has a width of at least 1000 mm,
The rolling roll has three or more regions in the width direction,
Temperature control is carried out for every area | region so that the difference of the maximum temperature and minimum temperature in the width direction of the surface of the said rolling roll may be 10 degrees C or less, The manufacturing method of the magnesium alloy rolling material characterized by the above-mentioned. The method for producing a magnesium alloy rolled material according to claim 8, wherein the temperature control is performed by introducing a heat oil whose temperature is adjusted in the rolling roll. The said temperature control is performed by attaching the heating fluid which adjusted temperature to the surface of the said rolling roll, The manufacturing method of the magnesium alloy rolling material of Claim 8 or 9 characterized by the above-mentioned. The magnesium alloy pressure according to any one of claims 8 to 10, wherein the temperature control is performed such that a temperature difference between two points 100 mm apart in the width direction from the surface of the rolling roll is 6 ° C or less. Method of manufacturing softwood. The surface of the magnesium alloy material immediately before passing through the rolling rolls is preheated so that the difference between the maximum temperature and the minimum temperature in the width direction is 8 ° C. or less. Method for producing a magnesium alloy rolled material. The preheating according to any one of claims 8 to 12, wherein the temperature difference between two points 100 mm apart in the width direction from the surface of the magnesium alloy material immediately before passing through the rolling roll is 6 ° C or less,
The said temperature control is performed on the surface of the said magnesium alloy rolling material immediately after passing through the said rolling roll so that the temperature difference of 2 points | pieces separated by 100 mm in the width direction may be 6 degrees C or less, The manufacturing method of the magnesium alloy rolling material characterized by the above-mentioned. .