Rolled magnesium alloy material, magnesium alloy structural member, and method for producing rolled magnesium alloy material

Patent metadata

Field	Value
Publication number	US-9598749-B2
Application number	US-201213985430-A
Country	US
Kind code	B2
Filing date	Feb 13, 2012
Priority date	Feb 14, 2011
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

Provided are a rolled Mg alloy material whose mechanical properties are locally different in a width direction, a Mg alloy structural member produced by plastically working the rolled Mg alloy material, and a method for producing the rolled Mg alloy material. The method for producing a rolled Mg alloy material includes rolling a Mg alloy material with a reduction roll. The reduction roll has three or more regions in the width direction. The temperature is controlled in each of the regions so that a difference between a maximum temperature and a minimum temperature exceeds 10° C. in the width direction of a surface of the reduction roll. The rolled state in the width direction is varied by varying a difference in temperature over the width direction of the reduction roll. As a result, it is possible to produce a rolled Mg alloy material whose mechanical properties are locally different in the width direction.

First claim

The invention claimed is:

1. A rolled magnesium alloy material produced by rolling a magnesium alloy material with a reduction roll,
wherein the magnesium alloy material contains aluminum in an amount of 8.3% by mass or more and 12% by mass or less,
wherein, in a width direction of the rolled magnesium alloy material,
a ratio O E /O C of a basal plane peak ratio of an edge portion to a basal plane peak ratio of a central portion satisfies O E /O C <0.89,
where the basal plane peak ratio O C of the central portion and the basal plane peak ratio O E of the edge portion are represented by formulae below:
basal plane 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)}
basal plane 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)}

 where I C (002), I C (100), I C (101), I C (102), I C (110), and I C (103) respectively represent X-ray diffraction peak intensities of a (002) plane, a (100) plane, a (101) plane, a (102) plane, a (110) plane, and a (103) plane in the central portion, and
I E (002), I E (100), I E (101), I E (102), I E (110), and I E (103) respectively represent X-ray diffraction peak intensities of the (002) plane, the (100) plane, the (101) plane, the (102) plane, the (110) plane, and the (103) plane in the edge portion,

wherein a thickness ratio t E /t C satisfies 0.97≦t E /t C ≦1.03 where t C denotes a thickness of a central portion in the width direction of the rolled Mg alloy material and t E denotes a thickness of an edge portion in the width direction of the rolled Mg alloy material,
wherein an elongation ratio E E /E C of the edge portion to the central portion satisfies 3/2<E E /E C , where E C denotes an elongation of the central portion in a tensile test in a rolling direction and E E denotes an elongation of the edge portion in a tensile test in a rolling direction.

2. The rolled magnesium alloy material according to claim 1 ,
wherein a tensile strength ratio Ts E /Ts C of the edge portion to the central portion satisfies Ts E /Ts C <0.9,
where Ts C denotes a tensile strength of the central portion in a tensile test in a rolling direction and Ts E denotes a tensile strength of the edge portion in a tensile test in a rolling direction.

3. The rolled magnesium alloy material according to claim 1 ,
wherein a 0.2% proof stress ratio Ps E /Ps C of the edge portion to the central portion satisfies Ps E /Ps C <0.9,
where Ps C denotes a 0.2% proof stress of the central portion in a tensile test in a rolling direction and Ps E denotes a 0.2% proof stress of the edge portion in a tensile test in a rolling direction.

4. The rolled magnesium alloy material according to claim 1 ,
wherein an average grain size ratio D E /D C of the edge portion to the central portion satisfies 3/2<D E /D C ,
where D C denotes an average grain size of the central portion of a cross section orthogonal to a rolling direction and D E denotes an average grain size of the edge portion of a cross section orthogonal to a rolling direction.

5. A magnesium alloy structural member produced by plastically working the rolled magnesium alloy material according to claim 1 .

Assignees

• Oishi Yukihiro
• Mori Nobuyuki
• Inoue Ryuichi
• Fujii Masaaki
• Ito Masahiko
• Kawabe Nozomu
• Sumitomo Electric Industries

Inventors

• Oishi Yukihiro
• Mori Nobuyuki
• Inoue Ryuichi
• Fujii Masaaki
• Ito Masahiko
• Kawabe Nozomu

Classifications

• C22C23/02 Primary

  with aluminium as the next major constituent · CPC title

• C22C23/04

  with zinc or cadmium as the next major constituent · CPC title

• B21B3/00 Primary

  Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences {; Rolling of aluminium, copper, zinc or other non-ferrous metals}(altering special metallurgical properties of alloys, other than structure consolidation or mechanical properties resulting therefrom C21D, C22F) · CPC title

• C22F1/06

  of magnesium or alloys based thereon · CPC title

• C22C23/06

  with a rare earth metal as the next major constituent · CPC title