CN118028662A - Al-Mg-Si aluminum alloy sheet and method for producing same - Google Patents
Al-Mg-Si aluminum alloy sheet and method for producing same Download PDFInfo
- Publication number
- CN118028662A CN118028662A CN202311312771.XA CN202311312771A CN118028662A CN 118028662 A CN118028662 A CN 118028662A CN 202311312771 A CN202311312771 A CN 202311312771A CN 118028662 A CN118028662 A CN 118028662A
- Authority
- CN
- China
- Prior art keywords
- mass
- aluminum alloy
- less
- alloy sheet
- content
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910000838 Al alloy Inorganic materials 0.000 title claims abstract description 181
- 229910018464 Al—Mg—Si Inorganic materials 0.000 title claims abstract description 40
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 40
- 150000001875 compounds Chemical class 0.000 claims abstract description 61
- 238000010438 heat treatment Methods 0.000 claims abstract description 46
- 238000000137 annealing Methods 0.000 claims abstract description 41
- 239000012535 impurity Substances 0.000 claims abstract description 14
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 9
- 238000000034 method Methods 0.000 claims description 43
- 238000005098 hot rolling Methods 0.000 claims description 26
- 238000005097 cold rolling Methods 0.000 claims description 24
- 230000008569 process Effects 0.000 claims description 22
- 238000000265 homogenisation Methods 0.000 claims description 15
- 239000013078 crystal Substances 0.000 description 21
- 239000000203 mixture Substances 0.000 description 15
- 238000005266 casting Methods 0.000 description 13
- 238000005096 rolling process Methods 0.000 description 13
- 238000002791 soaking Methods 0.000 description 13
- 230000000052 comparative effect Effects 0.000 description 11
- 238000001816 cooling Methods 0.000 description 10
- 238000001887 electron backscatter diffraction Methods 0.000 description 10
- 239000000463 material Substances 0.000 description 9
- 230000032683 aging Effects 0.000 description 8
- 238000005452 bending Methods 0.000 description 8
- 238000005259 measurement Methods 0.000 description 8
- 238000012360 testing method Methods 0.000 description 8
- 230000009467 reduction Effects 0.000 description 7
- 239000002210 silicon-based material Substances 0.000 description 7
- 239000011248 coating agent Substances 0.000 description 6
- 238000000576 coating method Methods 0.000 description 6
- 230000006872 improvement Effects 0.000 description 6
- 238000001953 recrystallisation Methods 0.000 description 6
- 238000009864 tensile test Methods 0.000 description 6
- 239000000956 alloy Substances 0.000 description 5
- 238000004458 analytical method Methods 0.000 description 5
- 238000002844 melting Methods 0.000 description 5
- 230000008018 melting Effects 0.000 description 5
- 239000002244 precipitate Substances 0.000 description 5
- 239000002994 raw material Substances 0.000 description 5
- 230000000630 rising effect Effects 0.000 description 5
- 229910019064 Mg-Si Inorganic materials 0.000 description 4
- 229910019406 Mg—Si Inorganic materials 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- 230000008520 organization Effects 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 229910018191 Al—Fe—Si Inorganic materials 0.000 description 3
- 229910018643 Mn—Si Inorganic materials 0.000 description 3
- 230000002411 adverse Effects 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000000445 field-emission scanning electron microscopy Methods 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 238000010791 quenching Methods 0.000 description 3
- 230000000171 quenching effect Effects 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 229910001369 Brass Inorganic materials 0.000 description 2
- 239000010951 brass Substances 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000004070 electrodeposition Methods 0.000 description 2
- 238000010894 electron beam technology Methods 0.000 description 2
- 230000006911 nucleation Effects 0.000 description 2
- 238000010899 nucleation Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- 230000003746 surface roughness Effects 0.000 description 2
- 229910021365 Al-Mg-Si alloy Inorganic materials 0.000 description 1
- 241001312219 Amorphophallus konjac Species 0.000 description 1
- 235000001206 Amorphophallus rivieri Nutrition 0.000 description 1
- 229920002752 Konjac Polymers 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000003483 aging Methods 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- CLOMYZFHNHFSIQ-UHFFFAOYSA-N clonixin Chemical compound CC1=C(Cl)C=CC=C1NC1=NC=CC=C1C(O)=O CLOMYZFHNHFSIQ-UHFFFAOYSA-N 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005315 distribution function Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000009957 hemming Methods 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 235000010485 konjac Nutrition 0.000 description 1
- 239000000252 konjac Substances 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 238000010422 painting Methods 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
- 230000037303 wrinkles Effects 0.000 description 1
Landscapes
- Metal Rolling (AREA)
Abstract
Provided are an Al-Mg-Si aluminum alloy sheet and a method for producing the same, which can obtain excellent surface properties and formability even when the temperature rise rate and the heating temperature during intermediate annealing are reduced. An Al-Mg-Si series aluminum alloy sheet comprising Si:0.50 mass% or more and 1.60 mass% or less, mg:0.25 mass% or more and 1.00 mass% or less, fe:0.05 mass% or more and 0.50 mass% or less, mn:0.01 mass% or more and 0.30 mass% or less, cu:0.001 mass% or more and 0.30 mass% or less, the balance comprising Al and unavoidable impurities, the Si content being represented by mass% as [ Si ], the [ Mg ]/[ Si ] content being represented by mass% being higher than 0.50, the cube orientation area ratio being 9% or less, and the number density of the compound having an equivalent circle diameter of 1.5 μm or more being 1000/mm 2 or more and 10000/mm 2 or less when the surface is observed.
Description
Technical Field
The present invention relates to an Al-Mg-Si aluminum alloy sheet excellent in surface properties and formability, and a method for producing an Al-Mg-Si aluminum alloy sheet capable of reducing CO 2 emissions during production.
Background
In recent years, there is an increasing social demand for weight reduction of automobile bodies from the viewpoint of global environment and the like. In order to cope with such a demand, aluminum alloy materials are used for large-sized vehicle body panels (outer panels and inner panels) in place of steel materials such as current steel plates in automobile bodies. In the large-sized vehicle body panels, aluminum alloy plates of JIS6000 series (hereinafter, abbreviated as 6000 series) of Al-Mg-Si series are used, particularly for outer panels (outer panels).
However, the 6000 series aluminum alloy sheet subjected to press forming has a problem that a streak pattern called wrinkles (RIDGING MARKS) and surface roughness are likely to occur. Accordingly, for example, patent document 1 discloses an aluminum alloy sheet which controls the composition of an aluminum alloy as a raw material, and controls the Cube orientation density (C), ND rotation Cube orientation density (N), RD rotation Cube orientation density (G) of crystal grains present in the sheet, and the ratio of (N) to (C), and the ratio of (G) to (C). It is described that according to the above patent document 1, an aluminum alloy sheet for forming processing excellent in surface roughness resistance and wrinkling resistance can be obtained.
Patent document 2 discloses a method for producing a rolled aluminum alloy sheet for forming, in which an ingot made of an aluminum alloy having a predetermined composition is cold-rolled without intermediate annealing by controlling the average cooling rate after homogenization, the total cold rolling rate, and the holding conditions before hot rolling. It is described that according to patent document 2, an aluminum alloy rolled sheet for forming excellent in bending and wrinkling resistance can be produced.
On the other hand, since extrusion molding is generally performed on an exterior member for an automobile, excellent formability is also required for an aluminum alloy sheet to be applied. In particular, automobile manufacturers in europe and america require an exterior panel excellent in formability, and a material having a plastic strain smaller than the anisotropy (Δr) of (lankford value) (r value), which is one of indexes for evaluating the formability of a plate material, is required. However, in the methods for producing aluminum alloy sheet or aluminum alloy rolled sheet described in patent documents 1 and 2, there is a fear that the control of the orientation other than Cube orientation is insufficient, the anisotropy of r value is large, or the average r value is low.
Further, patent document 3 discloses an aluminum alloy sheet in which aluminum alloy composition is controlled and anisotropy of plastic strain ratio (r value) and an inside limit bending radius in 180 ° bending after 15% elongation deformation are specified. It is described therein that the aluminum alloy sheet excellent in bending and paint bake hardenability, particularly suitable for outer sheets for automobiles, can be obtained according to the above patent document 3.
Further, patent document 4 discloses an aluminum alloy sheet in which the composition of the aluminum alloy sheet is controlled, and after solution treatment and quenching, the maximum diameter of mg—si based compounds is 10 μm or less, the number of compounds having diameters of 2 to 10 μm is 1000 pieces/mm 2 or less, and the inside limit bending radius under prescribed conditions is 0.5mm.
However, in the aluminum alloy sheet described in patent document 4, the r value is also high, but the anisotropy of the r value is high, and the desired formability cannot be obtained. In patent document 4, the anisotropy of the r value is not considered, and there is a possibility that the desired anisotropy of the r value cannot be obtained.
Accordingly, patent document 5 discloses an aluminum alloy sheet in which the aluminum alloy composition is controlled, and the Cube orientation density distribution, the average value of r values, the absolute value of the in-plane anisotropy index of r values, the average grain diameter, and the yield strength after aging and the yield strength after heating are specified. It is described that, according to patent document 5, an al—mg—si-based aluminum alloy sheet for automobile panels, which is excellent in all of press formability, bending workability by hemming, formability, bake hardenability by painting, and corrosion resistance, can be obtained.
Further, patent document 6 discloses an aluminum alloy sheet in which the aluminum alloy composition is controlled, and the total peak strength of Cube orientation, brass orientation, S orientation, P orientation, Q orientation is limited to a predetermined range, and the standard deviation of Cube orientation area ratio W and the conductivity after final tempering are controlled. It is described that, according to patent document 6, 6000 series aluminum alloy sheets excellent in press formability, crease property, and BH property can be obtained.
Prior art literature
Patent literature
Patent document 1: japanese patent No. 5415016
Patent document 2: japanese patent No. 6208389
Patent document 3: japanese patent No. 4633993
Patent document 4: japanese patent No. 4175818
Patent document 5: japanese patent No. 6301095
Patent document 6: japanese patent No. 6768568
Disclosure of Invention
Problems to be solved by the invention
However, in the intermediate annealing step, for example, a case of rapid heating in a continuous furnace system and a case of low-speed heating in a box furnace system are known. In the case type furnace system, a plurality of coiled materials can be intensively processed, and in the continuous furnace system, rapid heating is possible, and there are advantages in that anisotropy and surface properties are easily controlled.
In the production of the aluminum alloy sheet described in patent document 5, the intermediate annealing is performed at a temperature of, for example, 350 to 580 ℃ at a high temperature rising rate or at a relatively high intermediate annealing temperature. In addition, in the aluminum alloy sheet described in the above patent document 6, the intermediate annealing is also performed at a temperature rising rate of 5 ℃/s or more. Thus, in the above patent documents 5 and 6, the anisotropy and surface properties of the aluminum alloy sheet can be controlled.
However, when intermediate annealing is performed for manufacturing the aluminum alloy sheets described in patent documents 5 and 6, rapid heating or relatively high-temperature batch processing is required. Therefore, the CO 2 emissions in the production process are high, and burden is imposed on the global environment.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an Al-Mg-Si-based aluminum alloy sheet which can obtain excellent surface properties and formability even when the temperature rise rate and heating temperature during intermediate annealing are low, and a method for producing an Al-Mg-Si-based aluminum alloy sheet which can reduce the temperature rise rate and heating temperature during intermediate annealing, reduce CO 2 emissions during production, and obtain an Al-Mg-Si-based aluminum alloy sheet having excellent surface properties and formability.
Means for solving the problems
The above object of the present invention is achieved by the following constitution of [1] or [2] of an Al-Mg-Si series aluminum alloy sheet.
[1] An Al-Mg-Si series aluminum alloy sheet, comprising:
Si:0.50 mass% or more and 1.60 mass% or less;
Mg:0.25 mass% or more and 1.00 mass% or less;
fe:0.05 mass% or more and 0.50 mass% or less;
Mn:0.01 mass% or more and 0.30 mass% or less;
Cu:0.001 mass% or more and 0.30 mass% or less,
The balance comprising Al and unavoidable impurities,
The Si content is represented by mass% as [ Si ], and when the Mg content is represented by mass% as [ Mg ], the [ Mg ]/[ Si ] is higher than 0.50,
The Cube orientation has an area ratio of 9% or less,
When the surface is observed, the number density of the compound with the equivalent circle diameter of more than 1.5 μm is more than 1000/mm 2 and less than 10000/mm 2.
[2] An Al-Mg-Si series aluminum alloy sheet, comprising:
Si:0.50 mass% or more and 1.60 mass% or less;
Mg:0.25 mass% or more and 1.00 mass% or less;
fe:0.05 mass% or more and 0.50 mass% or less;
Mn:0.01 mass% or more and 0.30 mass% or less;
Cu:0.001 mass% or more and 0.30 mass% or less,
The balance comprising Al and unavoidable impurities,
The Si content is represented by mass% as [ Si ], and when the Mg content is represented by mass% as [ Mg ], the [ Mg ]/[ Si ] is 0.50 or less,
The Cube orientation has an area ratio of 12% or less,
When the surface is observed, the number density of the compound with the equivalent circle diameter of more than 1.5 μm is more than 600/mm 2 and less than 10000/mm 2.
The above object of the present invention is achieved by the following constitution of [3] or [4] of the method for producing an Al-Mg-Si series aluminum alloy sheet.
[3] A method for producing an Al-Mg-Si aluminum alloy sheet, characterized by using an Al-Mg-Si aluminum alloy ingot containing:
Si:0.50 mass% or more and 1.60 mass% or less;
Mg:0.25 mass% or more and 1.00 mass% or less;
fe:0.05 mass% or more and 0.50 mass% or less;
Mn:0.01 mass% or more and 0.30 mass% or less;
Cu:0.001 mass% or more and 0.30 mass% or less,
The balance comprising Al and unavoidable impurities,
The Si content is represented by mass% as [ Si ], and when the Mg content is represented by mass% as [ Mg ], the [ Mg ]/[ Si ] is higher than 0.50,
The manufacturing method comprises a homogenization heat treatment process, a hot rolling process, a cold rolling process, an intermediate annealing process and a solution treatment process,
The heat treatment temperature in the intermediate annealing step is lower than 500 ℃ and the heating rate is 1 ℃/sec or lower.
[4] A method for producing an Al-Mg-Si aluminum alloy sheet, characterized by comprising the steps of,
A method for producing an Al-Mg-Si aluminum alloy sheet according to [2] using an Al-Mg-Si aluminum alloy ingot containing:
Si:0.50 mass% or more and 1.60 mass% or less;
Mg:0.25 mass% or more and 1.00 mass% or less;
fe:0.05 mass% or more and 0.50 mass% or less;
Mn:0.01 mass% or more and 0.30 mass% or less;
Cu:0.001 mass% or more and 0.30 mass% or less,
The balance comprising Al and unavoidable impurities,
The Si content is represented by mass% as [ Si ], and when the Mg content is represented by mass% as [ Mg ], the [ Mg ]/[ Si ] is 0.50 or less,
The manufacturing method comprises a homogenization heat treatment process, a hot rolling process, a cold rolling process, an intermediate annealing process and a solution treatment process,
The heat treatment temperature in the intermediate annealing step is lower than 500 ℃ and the heating rate is 1 ℃/sec or lower.
ADVANTAGEOUS EFFECTS OF INVENTION
According to the present invention, it is possible to provide an Al-Mg-Si aluminum alloy sheet excellent in both surface properties and formability, and a method for producing an Al-Mg-Si aluminum alloy sheet capable of reducing CO 2 emissions during production.
Detailed Description
The present inventors have made intensive studies on the influence of a compound on the anisotropy and surface properties of an aluminum alloy sheet in order to solve the above problems. As a result, it was found that there is a range effective for formability and surface properties without seriously impairing elongation and bending by precisely controlling the size and number density of the compound.
Further, the present inventors have found that an Al-Mg-Si series aluminum alloy sheet having excellent surface properties and formability can be obtained even when the temperature rising rate and the heating temperature during intermediate annealing are reduced.
Further, the present inventors have paid attention to the ratio of Mg content to Si content contained in an aluminum alloy sheet, and have found that the ratio of both can be controlled to expand the allowable range of the area ratio of Cube orientation and the number density of a specific compound.
The present invention has been made based on these findings.
Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the embodiments described below, and may be modified and implemented arbitrarily without departing from the scope of the present invention.
[ Al-Mg-Si series aluminum alloy sheet ]
In the present embodiment, by controlling the content of the components contained in the al—mg—si based aluminum alloy sheet and controlling the area ratio of the specific Cube orientation and the number density of the specific compound, it is possible to obtain an al—mg—si based aluminum alloy sheet having excellent formability and surface shape. However, if the ratio of Mg content to Si content in the al—mg—si based aluminum alloy sheet is reduced, the allowable range of the area ratio of Cube orientation and the number density of specific compounds can be enlarged. Therefore, the case where the ratio of Mg content to Si content is larger than the predetermined value is referred to as "invention a", the case where the ratio of Mg content to Si content is equal to or smaller than the predetermined value is referred to as "invention B", and the chemical composition of the al—mg—si based aluminum alloy sheets of the invention a and the invention B and the reasons for limitation thereof are described, and the area ratio of Cube orientation and the number density of specific compounds are described.
The al—mg—si-based aluminum alloy sheet in the present invention is a sheet obtained by subjecting a rolled sheet such as a hot rolled sheet or a cold rolled sheet to a heat treatment such as a solution treatment or a quenching treatment, and is, for example, a raw material aluminum alloy sheet before an artificial aging treatment (artificial aging hardening treatment) such as a coating bake hardening treatment before forming an automobile member. Hereinafter, al-Mg-Si series aluminum alloy sheet is simply referred to as aluminum alloy sheet.
< Invention A >)
(Si: 0.50 mass% or more and 1.60 mass% or less)
Si and Mg form Mg-Si-based precipitate particles contributing to the strength improvement during an artificial aging treatment at a low temperature such as solution strengthening and a coating baking treatment, and exert an artificial aging hardening ability (BH property: bake Hardening). Therefore, si is an essential element for obtaining the strength (yield strength) required for an automobile panel material for an exterior panel and the like. In addition, si forms a Mg-Si compound of 1.5 μm or more together with Mg in casting, soaking, hot rolling and intermediate annealing steps, and precipitates and disperses, and this compound becomes a recrystallized nucleus, effectively contributing to the reduction of anisotropy and the improvement of surface properties.
If the Si content in the aluminum alloy sheet is less than 0.50 mass%, the amount of the Mg-Si based compound produced after the artificial aging heat treatment is insufficient, so that BH property is lowered and strength is insufficient. In addition, it is difficult to obtain desired r-value anisotropy and surface properties. Therefore, the Si content in the aluminum alloy sheet is 0.50 mass% or more, preferably 0.60 mass% or more, more preferably 0.65 mass% or more, relative to the total mass of the aluminum alloy sheet.
On the other hand, when the Si content in the aluminum alloy sheet is more than 1.60 mass%, coarse Si-based precipitates are formed and the ductility is lowered. Therefore, the Si content in the aluminum alloy sheet is 1.60 mass% or less, preferably 1.50 mass% or less, more preferably 1.45 mass% or less, relative to the total mass of the aluminum alloy sheet.
(Mg: 0.25 mass% or more and 1.00 mass% or less)
As described above, mg and Si form mg—si-based precipitate particles contributing to the improvement of strength during artificial aging at low temperatures such as solution strengthening and coating baking treatment, and exert an artificial age hardening ability. Therefore, mg is also an essential element for obtaining strength required for automotive panels such as exterior panels. In addition, mg forms mg—si based compounds of 1.5 μm or more together with Si in casting, soaking, hot rolling and intermediate annealing steps, and precipitates and disperses, and the compounds become nuclei for recrystallization, effectively contributing to the reduction of anisotropy and the improvement of surface properties.
If the Mg content in the aluminum alloy sheet is less than 0.25 mass%, the amount of mg—si based compound produced is insufficient, so BH property is significantly lowered and strength is insufficient. In addition, it is difficult to obtain desired r-value anisotropy and surface properties. Therefore, the Mg content in the aluminum alloy sheet is 0.25 mass% or more, preferably 0.27 mass% or more, more preferably 0.30 mass% or more, relative to the total mass of the aluminum alloy sheet.
On the other hand, if the Mg content in the aluminum alloy sheet is more than 1.00 mass%, the raw material strength at the time of forming increases, and the elongation at break and work hardening property decrease. Therefore, the Mg content in the aluminum alloy sheet is 1.00 mass% or less, preferably 0.90 mass% or less, more preferably 0.80 mass% or less, relative to the total mass of the aluminum alloy sheet.
(Fe: 0.05 mass% or more and 0.50 mass% or less)
Fe and Mn are elements that are generally contained in 6000-series aluminum alloys, and in the casting step, al-Fe-Mn-Si-series compounds of 1.5 μm or more are formed, and these compounds become nuclei for recrystallization, and are also effective in contributing to reduction of anisotropy and improvement of surface properties.
If the Fe content in the aluminum alloy sheet is less than 0.05 mass%, it is difficult to obtain desired r-value anisotropy and surface properties. Therefore, the Fe content in the aluminum alloy sheet is 0.05 mass% or more, preferably 0.10 mass% or more, more preferably 0.20 mass% or more, relative to the total mass of the aluminum alloy sheet. In the invention A, it is assumed that the value of [ Mg ]/[ Si ] to be described later is higher than 0.50. In this case, when the Fe content in the aluminum alloy sheet is 0.30 mass% or more relative to the total mass of the aluminum alloy sheet, relatively large compounds among the Al-Fe-Si compound can be dispersed during casting, and excellent formability and surface properties can be obtained.
On the other hand, when the Fe content in the aluminum alloy sheet is more than 0.50 mass%, the Al-Fe-Mn-Si based compound becomes coarse and dispersed at a high density, which becomes a factor of deterioration in formability. Therefore, the Fe content in the aluminum alloy sheet is 0.50 mass% or less, preferably 0.45 mass% or less, more preferably 0.40 mass% or less, relative to the total mass of the aluminum alloy sheet.
(Mn: 0.01 mass% or more and 0.30 mass% or less)
As described above, mn forms an Al-Fe-Mn-Si compound of 1.5 μm or more together with Fe in the casting, soaking and hot rolling steps, and this compound forms a recrystallized nucleus, which is also effective in contributing to the reduction of anisotropy and the improvement of surface properties.
If the Mn content in the aluminum alloy sheet is less than 0.01 mass%, it is difficult to obtain desired r-value anisotropy and surface properties. Therefore, the Mn content in the aluminum alloy sheet is 0.01 mass% or more, preferably 0.03 mass% or more, more preferably 0.05 mass% or more, relative to the total mass of the aluminum alloy sheet.
On the other hand, when the Mn content in the aluminum alloy sheet is more than 0.30 mass%, the Al-Fe-Mn-Si based compound becomes coarse and dispersed at a high density, which becomes a factor causing deterioration of formability. Therefore, the Mn content in the aluminum alloy sheet is 0.30 mass% or less, preferably 0.25 mass% or less, more preferably 0.20 mass% or less, relative to the total mass of the aluminum alloy sheet.
(Cu: 0.001 mass% or more and 0.30 mass% or less)
Cu is an element commonly contained in 6000 series aluminum alloys, and even if the Cu content is small, the strength and formability of the aluminum alloy sheet can be improved.
If the Cu content in the aluminum alloy sheet is less than 0.001 mass%, the effect of improving the strength and formability of the aluminum alloy sheet cannot be obtained. Therefore, the Cu content in the aluminum alloy sheet is 0.001 mass% or more, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, relative to the total mass of the aluminum alloy sheet.
On the other hand, if the Cu content in the aluminum alloy sheet is more than 0.30 mass%, the corrosion resistance of the aluminum alloy sheet is lowered. Therefore, the Cu content in the aluminum alloy sheet is 0.30 mass% or less, preferably 0.25 mass% or less, more preferably 0.20 mass% or less, relative to the total mass of the aluminum alloy sheet.
(Other Components)
In addition to Si, mg, fe, mn and Cu described above, the Al-Mg-Si series aluminum alloy sheet of the present embodiment may further contain Cr, zn and Ti according to the required mechanical properties. However, if the content of each component is excessive, the mechanical properties of the aluminum alloy sheet are lowered. Therefore, when at least one of Cr, zn and Ti is contained in the aluminum alloy sheet of the present embodiment, the Cr content is 0.1 mass% or less, the Zn content is 0.25 mass% or less, and the Ti content is 0.1 mass% or less with respect to the total mass of the aluminum alloy sheet.
(Balance: al and unavoidable impurities)
The Al-Mg-Si series aluminum alloy sheet of the present embodiment contains Si, mg, fe, mn and Cu as described above, cr, zn, or Ti depending on the desired mechanical properties, and the balance being Al and unavoidable impurities. As unavoidable impurities, B, zr, ni, bi, sn, and the like are mentioned. The content of these unavoidable impurities is preferably 0.05 mass% or less, respectively, relative to the total mass of the aluminum alloy sheet, and the total amount of the unavoidable impurities is preferably 0.15 mass% or less.
([ Mg ]/[ Si ]: higher than 0.50)
As a result of investigation of various components contained in an aluminum alloy sheet, the inventors have found that anisotropy of r-value varies depending on the numerical range of [ Mg ]/[ Si ], even if Cube orientation area ratio and number density of compounds are equal. Specifically, in invention A, the area ratio of Cube orientation {001} < 100 > and the number density of the compound having an equivalent circle diameter of 1.5 μm or more are defined as follows. Thus, even when the value of [ Mg ]/[ Si ] is higher than 0.50, the anisotropy of the r value can be reduced.
Here, the above-mentioned [ Si ] is a value representing the Si content in the aluminum alloy sheet in mass%, and the above-mentioned [ Mg ] is a value representing the Mg content in the aluminum alloy sheet in mass%.
(Cube orientation {001} < 100 > area ratio: 9% or less)
Cube orientation is an orientation in which r values in the rolling direction are high in the 0 and 90 DEG directions and low in the 45 DEG directions (such as well history, "gamma value of aluminum alloy sheet evaluated by quantitative analysis of a collection structure", light metal, 1994, vol.44, no.2, p.97-103). By controlling the area ratio of the Cube orientation to be low, the r value in the 45 ° direction, which is generally easy to be low in 6000 series alloys, can be increased, and the anisotropy Δr of the r value can be reduced.
In addition, cube orientation is known as a factor of surface properties (xiqing et Al, "crystal plastic analysis of wrinkling behavior occurring in al—mg—si alloy sheet materials", R & D Kobe steel report, 10 of 2012, vol.62, no.2, p.39-42). That is, by controlling the Cube orientation area ratio to be low, the surface properties can be also improved.
If the area ratio of Cube orientation {001} < 100 > is higher than 9%, the anisotropy Δr of r value becomes high, the formability is poor, and the surface properties are also deteriorated. Therefore, in the invention A, the area ratio of Cube orientation {001} < 100 > is set to 9% or less, preferably 8% or less.
Here, an example of definition of a collection organization and a measurement method will be described below.
(Definition of collection organization)
In a general aluminum alloy, it is known that the existence of a crystal orientation group structure is known, and the deformation state varies depending on the crystal orientation even when the same tensile deformation is applied, depending on the volume fraction of these crystal orientations.
Cube orientation: {001} < 100 >
Goss orientation: {011} < 100 >
Cube orientation: {112} < 111 >
Brass orientation: {011} < 211 >
S orientation: {123} < 634 >
P orientation: {011} < 211 >
Q orientation: {130} < 312 >
The method for expressing the crystal orientation group structure is expressed by a rolling surface and a rolling direction in the case of a rolled sheet. That is, the rolling surface is expressed as { O }, and the rolling direction is expressed as < × >. O and X represent integers (Chang island Jinyi, works of "collection organization", bolus Co., ltd., 1984, irvine, collection organization of aluminum alloy plate ", light metal, 1993, vol.43, no.5, p.285-293).
(Method for measuring aggregate tissue)
The above crystal orientation groups defined in the present invention were evaluated by the SEM-EBSD method using a scanning electron microscope (Scanning Electron Microscope: SEM) or a Field Emission-type scanning electron microscope (Field Emission-Scanning Electron Microscope: FE-SEM). For the sample to be measured, a cold-rolled sheet subjected to final heat treatment was prepared, and the surface of the cold-rolled sheet was mechanically polished and polished, and then electropolished to remove oxide film on the surface.
The SEM-EBSD method is commonly used as a method for measuring a crystal orientation group structure, and is a crystal orientation analysis method in which an electron back scattering diffraction image (EBSD: electronBack-SCATTERED DIFFRACTION PATTERN: EBSD) system is mounted on a field emission scanning electron microscope (for example, JSM-7000F manufactured by Japan electronics Co., ltd.).
The SEM-EBSD method irradiates a sample of an aluminum alloy plate provided in a column of the FE-SEM with an electron beam, and inputs an electron back scattering diffraction pattern into an EBSD device (for example, EBSD measuring and analyzing system: OIM (Orientation Imaging Macrograph) Data & Analysis, manufactured by TSL Co., ltd.) to perform crystal orientation Analysis while scanning the sample surface every 1 μm. Thus, EBSP (Electron Back Scatter Diffraction Pattern) points were obtained and their indices were calibrated to obtain the crystal orientation of the electron beam irradiation region. The obtained crystal orientation measurement data was rotated by 90 ° about the rolling direction axis, and then rotated by 90 ° in the rolling surface normal direction, and the crystal Orientation Distribution Function (ODF) and the area ratio when the EBSD-based crystal orientation measurement was performed in the entire measurement region were calculated and obtained. For the crystal orientation analysis method of the EBSD system mounted on the FE-SEM, for example, reference is made to the Konjac Steel works, 9 th 2002, vol.52, no.2, p.66-70, etc.
In the present embodiment, if the measured error of the crystal orientation is within ±15° from the crystal plane of Cube orientation {001} < 100 >, it is defined as belonging to the same orientation factor and the area ratio is calculated. This is because, if within such a range, the aluminum alloy sheet exhibits substantially the same properties.
( Number density of the compound having an equivalent circle diameter of 1.5 μm or more: 1000/mm 2 or more and 10000/mm 2 or less )
As described above, there is known an aluminum alloy sheet in which the elongation and bendability are improved by setting the maximum diameter of the compound in the aluminum alloy sheet to 10 μm or less and the number of the compound having a diameter of 2 to 10 μm to 1000 pieces/mm 2 or less.
On the other hand, in the present embodiment, the size and number density of the compound are precisely controlled, and thus, the anisotropy and surface properties are improved without seriously impairing the elongation and bending. This is presumably because, around a compound having an equivalent circle diameter of 1.5 μm or more, recrystallization is promoted, and as a result, a relatively random aggregate structure is likely to be formed. Since it is difficult to numerically define the randomness of the aggregate, in the present embodiment, the number density of the compound is used as an index indirectly indicating the randomness of the aggregate.
In the case of invention A, that is, in the case where the ratio of Mg content to Si content ([ Mg ]/[ Si ]) is higher than 0.50, if the number density of the compound having an equivalent circle diameter of 1.5 μm or more is lower than 1000 pieces/mm 2, the occurrence amount of recrystallized grains due to the particle excitation nucleation (PSN: particle stimulated nucleation) is small, and it is difficult to obtain a relatively random aggregate structure. As a result, the anisotropy of r-value may not be reduced, and good surface properties may not be obtained. Therefore, the number density of the compound having an equivalent circle diameter of 1.5 μm or more is 1000 pieces/mm 2 or more, preferably 1200 pieces/mm 2 or more, and more preferably 1500 pieces/mm 2 or more.
On the other hand, if the number density of the compound having an equivalent circle diameter of 1.5 μm or more is excessive, the strength and elongation of the aluminum alloy sheet are adversely affected. Therefore, the number density of the compound having an equivalent circle diameter of 1.5 μm or more is 10000 pieces/mm 2 or less, preferably 5000 pieces/mm 2 or less, more preferably 3000 pieces/mm 2 or less.
The number density of the compound having an equivalent circle diameter of 1.5 μm or more can be obtained by calculating the number of the compound having an equivalent circle diameter of 1.5 μm or more per unit area in 20 fields of view by using a scanning electron microscope having a magnification of 500. In this embodiment, an area of about 0.17mm by about 0.25mm was observed in 1 field of view, and the total of 20 fields of view measured an area of 0.86mm 2. Then, the number density can be calculated by dividing the total number of the above compounds in the actual 20 fields by the area of 0.86mm 2.
Next, the chemical composition and the like of the al—mg—si based aluminum alloy sheet of the invention B will be described, and the area ratio of Cube orientation and the number density of specific compounds will be described.
< Invention B >)
In invention B, the ranges and reasons for limitation of the respective contents of Si, mg, fe, mn and Cu contained in the aluminum alloy sheet are the same as in invention A. Therefore, the ratio of Mg content to Si content, the area ratio of Cube orientation, and the number density of the compound having an equivalent circle diameter of 1.5 μm or more, which are different from that of invention a, will be described below.
([ Mg ]/[ Si ]: below 0.50)
As described above, the inventors have found that even in a material having a small [ Mg ]/[ Si ], the anisotropy of r-value is small even if Cube orientation area ratio and number density of the compound are equivalent. This is presumably because the low [ Mg ]/[ Si ] causes a change in the recrystallization behavior during intermediate annealing and solution treatment, and affects the formation of other orientations than Cube orientation. That is, in the invention B, the range of the area ratio of the Cube orientation {001} < 100 > and the number density of the compound having the equivalent circle diameter of 1.5 μm or more can be widened by controlling the value of [ Mg ]/[ Si ] to 0.50 or less. The value of [ Mg ]/[ Si ] is preferably 0.45 or less, more preferably 0.30 or less.
As in invention A, the above-mentioned [ Si ] is a value representing the Si content in the aluminum alloy sheet in mass%, and the above-mentioned [ Mg ] is a value representing the Mg content in the aluminum alloy sheet in mass%.
In invention B, in which the value of [ Mg ]/[ Si ] is limited to 0.50 or less, when the Fe content in the aluminum alloy sheet is 0.20 mass% or more relative to the total mass of the aluminum alloy sheet, relatively large compounds among Al-Fe-Si based compounds can be dispersed during casting, and excellent formability and surface properties can be obtained.
(Cube orientation {001} < 100 > area ratio: 12% or less)
When the value of [ Mg ]/[ Si ] is 0.50 or less, if the area ratio of Cube orientation {001} < 100 > is more than 12%, the anisotropy Δr of r value increases, the formability is deteriorated, and the surface properties are also deteriorated. Therefore, in the invention B, the area ratio of Cube orientation {001} < 100 > is set to 12% or less, preferably 11% or less, and more preferably 10% or less. The method for measuring the aggregate structure is the same as that of the invention a.
( Number density of the compound having an equivalent circle diameter of 1.5 μm or more: 600/mm 2 or more and 10000/mm 2 or less )
When the number density of the compound having an equivalent circle diameter of 1.5 μm or more is less than 600 grains/mm 2, the occurrence amount of recrystallized grains is small, and it is difficult to obtain a relatively random aggregate structure. As a result, the anisotropy of r-value cannot be reduced, and good surface properties cannot be obtained. Therefore, the number density of the compound having an equivalent circle diameter of 1.5 μm or more is 600 pieces/mm 2 or more, preferably 700 pieces/mm 2 or more, and more preferably 800 pieces/mm 2 or more.
On the other hand, if the number density of the compound having an equivalent circle diameter of 1.5 μm or more is excessive, the strength and elongation of the aluminum alloy sheet are adversely affected. Therefore, the number density of the compound having an equivalent circle diameter of 1.5 μm or more is 10000 pieces/mm 2 or less, preferably 5000 pieces/mm 2 or less, more preferably 3000 pieces/mm 2 or less.
[ Method for producing Al-Mg-Si-based aluminum alloy sheet ]
The method for producing an Al-Mg-Si aluminum alloy sheet according to the present embodiment, the method of producing the Al-Mg-Si aluminum alloy sheet of the invention A and the method of producing the Al-Mg-Si aluminum alloy sheet of the invention B. Specifically, an aluminum alloy ingot having a desired composition is prepared by melting and casting a material having the desired composition, and a homogenization heat treatment step, a hot rolling step, a cold rolling step, an intermediate annealing step, and a solution treatment step are provided as steps that are generally performed, whereby a heating temperature and a heating rate in the intermediate annealing step are defined.
In the present embodiment, it is preferable to control the components contained in the aluminum alloy sheet and to appropriately control the conditions of the homogenization heat treatment step and the hot rolling step so that the larger compound can be dispersed before cold rolling.
By dispersing the larger compound before cold rolling, recrystallization around the compound is liable to occur at the time of intermediate annealing or solution treatment. As a result, aggregation of Cube orientation of r45 is reduced, crystal orientation is easily random, anisotropy of r value can be reduced, and surface properties can be improved.
In particular, in the present embodiment, as a method for dispersing a relatively large compound before cold rolling, the following 3 methods are exemplified
(1) The homogenization heat treatment is performed in 2 times or 2 stages.
(2) The end temperature of the hot rolling is raised and the cooling rate after the hot rolling is slowed down.
(3) The Fe content in the aluminum alloy sheet is controlled.
Among them, by using at least 1 method, an Al-Mg-Si series aluminum alloy sheet excellent in formability and surface properties can be produced.
Hereinafter, the method for producing Al-Mg-Si series aluminum alloy sheets of the invention A and the invention B will be described in more detail.
< Melting, casting Process >)
An aluminum alloy material having the above desired composition is melted, and an aluminum alloy ingot having a predetermined shape is produced from the molten metal. The method for melting and casting the aluminum alloy material is not particularly limited, and a conventional method or a known method may be used.
As described in the column of the Fe content of the aluminum alloy sheet and in the above (3), if the Fe content in the aluminum alloy sheet is controlled, a relatively large Al-Fe-Si compound can be dispersed during casting. That is, in producing the aluminum alloy sheet of the invention A, it is preferable that the Fe content in the aluminum alloy ingot is 0.30 mass% or more. In the production of the aluminum alloy sheet according to the invention B, it is preferable that the Fe content in the aluminum alloy ingot is 0.20 mass% or more. In this way, when the Fe content in the aluminum alloy material and the aluminum alloy ingot is increased, an al—mg—si-based aluminum alloy sheet having excellent formability and surface properties can be produced.
< Homogenization Heat treatment Process >
Next, the cast aluminum alloy ingot is subjected to a homogenization heat treatment (soaking treatment). This homogenizing heat treatment is performed to make the uneven structure uniform at the time of casting. The temperature of the homogenization heat treatment is not particularly limited, but below 480 ℃, the strength after artificial aging is liable to be lowered. Therefore, the homogenization heat treatment temperature is preferably 480℃or higher and lower than the melting point, more preferably 500℃or higher.
The average cooling rate during cooling from 480 ℃ to 300 ℃ after the homogenization heat treatment is preferably 500 ℃/hr or less, more preferably 100 ℃/hr or less.
As described in (1), in the present embodiment, soaking treatment is preferably performed in 2 or 2 stages. By dividing the soaking treatment into 2 times or 2 stages, a large amount of mg—si compound can be distributed in the cooling process after the 1 st soaking treatment or the heating process of the 2 nd soaking treatment. The soaking treatment may be divided into 2 times or 2 stages, depending on the equipment to which the soaking treatment can be applied.
< Hot Rolling Process >)
After the homogenization heat treatment, hot rolling is performed so that the raw material reaches a predetermined thickness.
As described in (2), in the present embodiment, it is preferable that the finishing temperature of the hot rolling is high and the cooling rate after the hot rolling is low. This can lengthen the cooling step after the completion of hot rolling, and in this step, a large amount of mg—si compound can be distributed. Therefore, the finishing temperature of the hot rolling is preferably 370℃or higher, more preferably 390℃or higher.
The average cooling rate of the hot-rolling-completed cooling from the hot-rolling-completed temperature to 300 ℃ is preferably 500 ℃/hr or less, more preferably 100 ℃/hr or less.
< Cold Rolling Process >)
The hot-rolled sheet obtained in the hot-rolling step is cold-rolled to obtain a cold-rolled sheet. After the intermediate annealing step described later, the cold rolling step is preferably repeated as necessary.
(Total Rolling Rate: 75% or more)
In the manufacturing methods of aluminum alloy sheets of the invention a and the invention B, when the total rolling rate of cold rolling is increased, the density of Cube orientation can be reduced, and thus the area ratio of Cube orientation can be reduced, and good formability and surface properties can be obtained. Therefore, the total rolling reduction in the entire cold rolling process from the hot rolling process to the final sheet thickness through the intermediate annealing process is preferably 75% or more, more preferably 78% or more. The total rolling reduction is the reduction in plate thickness after all cold rolling steps are completed, relative to the plate thickness after hot rolling.
< Intermediate annealing Process >)
Since the cold-rolled sheet is work-hardened by the cold-rolling process, the intermediate annealing is performed to soften the sheet, thereby improving the subsequent working efficiency and reducing cracks during the working. In the method for manufacturing aluminum alloy sheets of the invention A and the invention B, the intermediate annealing is performed, and recrystallization repeatedly occurs, so that a relatively random structure is easily obtained, and as a result, a good surface property can be obtained relatively easily. As described above, the anisotropy and surface properties of the aluminum alloy sheet are easily controlled by increasing the temperature or the temperature increasing rate of the intermediate annealing, but on the other hand, increasing the temperature or the temperature increasing rate of the intermediate annealing places a burden on the environment. In the aluminum alloy sheet of the invention A and the invention B, excellent surface properties and formability can be obtained even when the temperature rising speed and the heating temperature are reduced by controlling the area ratio of Cube orientation and the number density of specific compounds.
If the heat treatment temperature in the intermediate annealing step is 500 ℃ or higher, or if the heating rate is higher than 1 ℃/sec, high heat is required in the intermediate annealing step, which adversely affects the environment. Therefore, the heat treatment temperature in the intermediate annealing step is lower than 500 ℃, preferably 460 ℃ or lower. The temperature rise rate in the intermediate annealing step is preferably 1 ℃/sec or less and 500 ℃/hr or less, and more preferably 100 ℃/hr or less. Here, the temperature rise rate is an average temperature rise rate from room temperature to an arrival temperature.
< Procedure of solution treatment >)
After cold rolling, solution treatment is performed. The temperature in the solution treatment step is not particularly limited, and is preferably, for example, at a temperature of 480 ℃ or higher and 570 ℃ or lower for 1 to 120 seconds.
The method for producing the aluminum alloy sheet of the invention a and the method for producing the aluminum alloy sheet of the invention B are not limited to the above production methods, and may be modified and implemented arbitrarily without departing from the scope of the invention.
Examples
The present invention is not limited to the examples, but can be modified and practiced within the scope of the gist of the present invention, and these are included in the technical scope of the present invention.
< Manufacturing of aluminum alloy plate >)
Aluminum alloy sheets having various compositions are manufactured by various manufacturing methods. Hereinafter, a specific manufacturing method of each aluminum alloy sheet will be described. The aluminum alloy sheet of the invention A was used in the invention examples Nos. A1 to A3, the comparative examples Nos. A4 and A5, and the aluminum alloy sheet of the invention B was used in the invention examples Nos. B1 to B4, and the comparative example No. B5.
(Production of aluminum alloy sheets of invention examples No. A1, B2)
Ingots of each composition shown in Table 1 were melted by a semi-continuous casting method (DC casting method: DIRECT CHILL CASTING processes). Next, a homogenization heat treatment was performed as a 2-stage heat treatment. The 1 st soaking treatment temperature is 560 ℃, and the temperature is reduced to room temperature by air cooling. Thereafter, the hot rolling was performed after heating again to 420 ℃. The finishing temperature of the hot rolling is 280-420 ℃, and then slow cooling is performed. The thickness of the aluminum alloy sheet after the completion of hot rolling is 2.3mm to 6.0mm. Then, after cold rolling the aluminum alloy sheet after hot rolling at various cold rolling rates, intermediate annealing is performed by using a batch gas furnace at a heating rate of 40 ℃/h (0.011 ℃/sec), and after the intermediate annealing is completed, cold rolling is performed again at various cold rolling rates. The final plate thickness after cold rolling is 0.4-1.0 mm. Thereafter, the solution was treated in a salt bath furnace at 560℃for 30 seconds, cooled by water, and cooled to room temperature. Thereafter, the aluminum alloy sheets of invention examples No. A1, B1, and B2 were produced by holding at room temperature for about 1 week.
(Production of aluminum alloy sheets of invention examples No. A2, B3, and B4, comparative examples No. A4, A5, and B5)
As in the above-mentioned invention example No. A1, the aluminum alloy sheets of invention examples No. A2, B3 and B4 and comparative examples No. A4, A5 and B5 were produced by melting the ingot, soaking at 560℃for 1 time, hot rolling, cold rolling, intermediate annealing, 2 nd cold rolling and solution treatment, and holding at room temperature for about 1 week.
(Production of aluminum alloy sheet of invention example No. A3)
An ingot was melted in the same manner as in inventive example No. a2, subjected to soaking treatment 1 time, and then hot rolled. Then, as additional annealing for verifying the effect of dispersing the compound after completion of hot rolling, solution treatment was performed at 560 ℃ for 4 hours, and then quenching was performed after maintaining at 410 ℃ for 16 hours. Thereafter, cold rolling, intermediate annealing, cold rolling for the 2 nd time, and solution treatment were performed and kept at room temperature for about 1 week, thereby manufacturing an aluminum alloy sheet of invention example No. a 3.
In the production of invention examples nos. a1 to A3, comparative examples nos. a4 to A5, invention examples nos. B1 to B4, and comparative example No. B5, the conditions of the respective steps are shown in table 2 below. Further, since the composition of the obtained aluminum alloy sheet is the same as that of the aluminum alloy ingot as a raw material, the descriptions in the table are omitted.
(Measurement of aggregate tissue)
For the aluminum alloy sheets of the obtained invention examples and comparative examples, the structure of the crystal orientation was measured, and the area ratio of Cube orientation was calculated. The method for measuring the aggregate tissue is as described in the above embodiment. If the measured crystal orientation deviation is within + -15 DEG from the crystal plane of the Cube orientation {001} < 100 >, the area ratio of Cube orientation is defined as belonging to the same orientation factor and calculated.
(Measurement of number Density of Compound having equivalent circle diameter of 1.5 μm or more)
The number density of the compound having an equivalent circle diameter of 1.5 μm or more was measured for the aluminum alloy sheets of the obtained invention examples and comparative examples. The method for measuring the number density is as described in the above embodiment.
The area ratio of Cube orientation is shown in Table 1 below together with the measurement result of the number density of the compound having an equivalent circle diameter of 1.5 μm or more.
< Evaluation test >)
(Plastic Strain ratio test)
Tensile test pieces were extracted from the respective aluminum alloy sheets obtained. The tensile test piece was produced by extracting JISZ2241 from each aluminum alloy sheet such that the tensile direction was parallel (0 °), 45 °, and perpendicular (90 °) to the rolling direction: 2011 (short side: 12.5mm, gauge Length (GL: gauge Length): 50 mm), and tensile test was performed at room temperature. In the tensile test, the yield strength of 0.2% was measured 5mm/min before and 30mm/min after, and the yield strength of 0.2% and the r value at 15% plastic strain were measured. In addition, according to the following equation (S1), the in-plane anisotropy Δr is calculated, and according to the following equation (S2), the average plastic strain ratio rA is calculated.
Deltar=1/2× (r0-2×r45+r90) … formula (S1)
RA=1/4× (r0+2×r45+r90) … (S2)
The number of measurements for each tensile test was 2, and the various characteristics were averaged.
(Evaluation criteria for tensile test)
As an evaluation criterion for use as an automobile exterior material, it was judged that the aluminum alloy sheet was acceptable in press formability in that Δr was 0.25 or less and r value (r 90) in the 90 ° direction was 0.60 or more.
(Surface Property test)
Test pieces were extracted from the respective aluminum alloy sheets thus obtained, and after plastic strain of 15% was applied in a direction perpendicular to the rolling direction, electrodeposition coating (ED: electrodeposition coating) was performed.
(Evaluation criteria for surface Property test)
The test piece after ED coating was visually evaluated for the presence or absence of a pattern, and the test piece was rated as "good" when no surface pattern was observed at all, as "delta" when a slight surface pattern was observed, as "x" (poor) when a clear surface pattern was observed, and was rated as "delta" or "above" when the test piece was rated as "3" when no surface pattern was observed.
The measurement results of the formability and the surface properties are shown in table 3 below.
[ Table 1]
[ Table 2]
/>
[ Table 3]
As shown in tables 1 to 3, the chemical compositions of the aluminum alloy sheets in invention examples No. A1 to A3 and invention examples No. B1 to B4 are within the range defined by the present invention, and the area ratio of Cube orientation and the number density of the compound having a circle equivalent diameter of 1.5 μm or more are within the range defined by the present invention, so that an aluminum alloy sheet excellent in formability and surface properties can be obtained even when the temperature rising rate and heating temperature at the time of intermediate annealing are reduced.
On the other hand, in comparative example No. a4, the area ratio of Cube orientation exceeds the upper limit of the numerical range defined in the present invention, and the number density of the compound having an equivalent circle diameter of 1.5 μm or more is lower than the lower limit of the numerical range defined in the present invention, so that the value of in-plane anisotropy Δr becomes large and the moldability is poor. In comparative example No. A5, the number density of the compound having an equivalent circle diameter of 1.5 μm or more was lower than the lower limit of the numerical range defined in the present invention, and therefore the in-plane anisotropy Δr was large, and the moldability was poor. In comparative example No. b5, since the Cube orientation has an area ratio exceeding the upper limit of the numerical range defined in the present invention, the in-plane anisotropy Δr has a large value and poor formability.
Claims (4)
1. An Al-Mg-Si series aluminum alloy sheet, comprising:
Si:0.50 to 1.60 mass%,
Mg:0.25 to 1.00 mass%,
Fe:0.05 to 0.50 mass% inclusive,
Mn:0.01 to 0.30 mass%,
Cu:0.001 mass% or more and 0.30 mass% or less,
The balance comprising Al and unavoidable impurities,
The Si content is represented by mass% as [ Si ], and when the Mg content is represented by mass% as [ Mg ], the [ Mg ]/[ Si ] is higher than 0.50,
The Cube orientation has an area ratio of 9% or less,
When the surface is observed, the number density of the compound with the equivalent circle diameter of more than 1.5 μm is more than 1000/mm 2 and less than 10000/mm 2.
2. An Al-Mg-Si series aluminum alloy sheet, comprising:
Si:0.50 to 1.60 mass%,
Mg:0.25 to 1.00 mass%,
Fe:0.05 to 0.50 mass% inclusive,
Mn:0.01 to 0.30 mass%,
Cu:0.001 mass% or more and 0.30 mass% or less,
The balance comprising Al and unavoidable impurities,
The Si content is represented by mass% as [ Si ], and when the Mg content is represented by mass% as [ Mg ], the [ Mg ]/[ Si ] is 0.50 or less,
The Cube orientation has an area ratio of 12% or less,
When the surface is observed, the number density of the compound with the equivalent circle diameter of more than 1.5 μm is more than 600/mm 2 and less than 10000/mm 2.
3. A method for producing an Al-Mg-Si aluminum alloy sheet, characterized by using an Al-Mg-Si aluminum alloy ingot, the Al-Mg-Si series aluminum alloy ingot according to claim 1, wherein the Al-Mg-Si series aluminum alloy ingot comprises:
Si:0.50 to 1.60 mass%,
Mg:0.25 to 1.00 mass%,
Fe:0.05 to 0.50 mass% inclusive,
Mn:0.01 to 0.30 mass%,
Cu:0.001 mass% or more and 0.30 mass% or less,
The balance comprising Al and unavoidable impurities,
The Si content is represented by mass% as [ Si ], and when the Mg content is represented by mass% as [ Mg ], the [ Mg ]/[ Si ] is higher than 0.50,
The manufacturing method comprises a homogenization heat treatment process, a hot rolling process, a cold rolling process, an intermediate annealing process and a solution treatment process,
The heat treatment temperature in the intermediate annealing step is lower than 500 ℃ and the heating rate is 1 ℃/sec or lower.
4. A method for producing an Al-Mg-Si aluminum alloy sheet, characterized by using an Al-Mg-Si aluminum alloy ingot, the Al-Mg-Si series aluminum alloy ingot according to claim 2, comprising:
Si:0.50 to 1.60 mass%,
Mg:0.25 to 1.00 mass%,
Fe:0.05 to 0.50 mass% inclusive,
Mn:0.01 to 0.30 mass%,
Cu:0.001 mass% or more and 0.30 mass% or less,
The balance comprising Al and unavoidable impurities,
The Si content is represented by mass% as [ Si ], and when the Mg content is represented by mass% as [ Mg ], the [ Mg ]/[ Si ] is 0.50 or less,
The manufacturing method comprises a homogenization heat treatment process, a hot rolling process, a cold rolling process, an intermediate annealing process and a solution treatment process,
The heat treatment temperature in the intermediate annealing step is lower than 500 ℃ and the heating rate is 1 ℃/sec or lower.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2022-182123 | 2022-11-14 | ||
| JP2022182123A JP2024071270A (en) | 2022-11-14 | 2022-11-14 | Al-Mg-Si aluminum alloy plate and its manufacturing method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118028662A true CN118028662A (en) | 2024-05-14 |
Family
ID=90993934
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311312771.XA Pending CN118028662A (en) | 2022-11-14 | 2023-10-11 | Al-Mg-Si aluminum alloy sheet and method for producing same |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2024071270A (en) |
| CN (1) | CN118028662A (en) |
-
2022
- 2022-11-14 JP JP2022182123A patent/JP2024071270A/en active Pending
-
2023
- 2023-10-11 CN CN202311312771.XA patent/CN118028662A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JP2024071270A (en) | 2024-05-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR102211691B1 (en) | High strength 7XXX series aluminum alloy and its manufacturing method | |
| EP3245309B1 (en) | Highly formable automotive aluminum sheet with reduced or no surface roping and a method of preparation | |
| KR20210095716A (en) | High strength 6xxx series aluminum alloys and methods of making the same | |
| US20040094249A1 (en) | Aluminum alloy sheet excellent in formability and hardenability during baking of coating and method for production thereof | |
| KR20150013925A (en) | Aluminum alloy sheet for forming and process for manufacturing the same | |
| WO2015034024A1 (en) | Aluminum alloy plate having excellent bake hardening properties | |
| WO2016204043A1 (en) | High strength aluminum alloy hot-forged material | |
| KR20170140771A (en) | High-strength 6000-based alloy thick plate having uniform strength in plate thickness direction and method for manufacturing the same | |
| EP3135790A1 (en) | Method for manufacturing aluminum alloy member and aluminum alloy member using same | |
| JP2006257475A (en) | Al-Mg-Si ALLOY SHEET SUPERIOR IN PRESS FORMABILITY, MANUFACTURING METHOD THEREFOR AND AUTOMOTIVE SKIN PLATE OBTAINED FROM THE SHEET MATERIAL | |
| JP3748859B2 (en) | High-strength copper alloy with excellent bendability | |
| JP5813358B2 (en) | Highly formable Al-Mg-Si alloy plate and method for producing the same | |
| KR101159410B1 (en) | Alluminum alloy sheet superior in paint baking hardenability and invulnerable to room temperature aging, and method for production thereof | |
| JP5111966B2 (en) | Method for manufacturing aluminum alloy panel | |
| JP2008062255A (en) | SUPERPLASTIC MOLDING METHOD FOR Al-Mg-Si BASED ALUMINUM ALLOY SHEET HAVING REDUCED GENERATION OF CAVITY, AND Al-Mg-Si BASED ALUMINUM ALLOY MOLDED SHEET | |
| JP6768568B2 (en) | Aluminum alloy plate with excellent press formability, rigging mark property, and BH property | |
| JP2004124213A (en) | Aluminum alloy sheet for panel forming, and its manufacturing method | |
| CN118028662A (en) | Al-Mg-Si aluminum alloy sheet and method for producing same | |
| WO2021214890A1 (en) | Magnesium alloy plate, press compact, and method for manufacturing magnesium alloy plate | |
| JP3226259B2 (en) | Aluminum alloy plate excellent in formability, bake hardenability and corrosion resistance and method for producing the same | |
| JPH10259464A (en) | Production of aluminum alloy sheet for forming | |
| JP4022497B2 (en) | Method for manufacturing aluminum alloy panel | |
| US20200157668A1 (en) | Aluminum alloy plate and method for producing the same | |
| WO2016056240A1 (en) | Superplastic-forming aluminium alloy plate and production method therefor | |
| JP6005613B2 (en) | Aluminum alloy sheet with excellent bake hardenability |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination |