JP2019026897A - Aluminum alloy sheet for structural member, and manufacturing method of aluminum alloy structural member - Google Patents

Aluminum alloy sheet for structural member, and manufacturing method of aluminum alloy structural member Download PDF

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JP2019026897A
JP2019026897A JP2017148116A JP2017148116A JP2019026897A JP 2019026897 A JP2019026897 A JP 2019026897A JP 2017148116 A JP2017148116 A JP 2017148116A JP 2017148116 A JP2017148116 A JP 2017148116A JP 2019026897 A JP2019026897 A JP 2019026897A
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plate
structural
cube orientation
thickness
area ratio
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真弘 山口
Shinko Yamaguchi
真弘 山口
松本 克史
Katsushi Matsumoto
克史 松本
有賀 康博
Yasuhiro Ariga
康博 有賀
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株式会社神戸製鋼所
Kobe Steel Ltd
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Abstract

To provide a 6000 series aluminum alloy structural member having strength and crush resistance, and a stock sheet thereof.SOLUTION: Both of strength and crush resistance are achieved by setting average area percentage of a Cube orientation of a structural member surface consisting of a 6000 series aluminum alloy with a specific composition, and average area percentage of the Cube orientation at a 1/4 thickness position of thickness of the structural member at a constant value or more, and making the average area percentage of the Cube orientation at the 1/4 thickness position of thickness of the structural member larger than the average area percentage of the Cube orientation of the structural member surface.SELECTED DRAWING: None

Description

本発明は、高強度と耐圧壊性とを兼備したアルミニウム合金構造部材用のアルミニウム合金板およびこのアルミニウム合金板を素材とするアルミニウム合金構造部材の製造方法に関するものである。   The present invention relates to an aluminum alloy plate for an aluminum alloy structural member having both high strength and pressure resistance, and a method for producing an aluminum alloy structural member using the aluminum alloy plate as a raw material.
自動車からの排出ガスによる地球環境問題に対して、自動車等の輸送機器の燃費向上が求められている。このため、特に、自動車構造部材として、従来から使用されている鋼材に替わって、より軽量なアルミニウム合金材が適用されるようになっている。素材をアルミニウム合金板とする代表的な自動車構造部材としては、素材板がプレス成形された、フード、フェンダー、ドア、ルーフなどの薄板のパネル材があるが、これとは別に、更に、板厚が2mm以上で比較的厚く、剛性が要求される構造部材としての自動車構造部材にまで拡大しようとしている。   In response to global environmental problems caused by exhaust gas from automobiles, improvement in fuel consumption of transportation equipment such as automobiles is required. For this reason, in particular, a lighter aluminum alloy material is applied as an automobile structural member in place of a conventionally used steel material. Typical automotive structural members that use aluminum alloy plates include thin panel materials such as hoods, fenders, doors, and roofs, which are made by press forming the material plates. However, it is going to be expanded to an automobile structural member as a structural member requiring a rigidity of 2 mm or more and relatively thick.
これら比較的板厚が厚く、剛性が要求されるような構造部材用の自動車構造部材は、前記自動車パネルに比べて、素材板の更なる高強度化や、車体衝突時の衝撃吸収性=耐圧壊性(圧壊特性あるいは圧壊性とも言う)の特性付与などが新たに必要である。   Compared to the above-mentioned automobile panels, automobile structural members for structural members that are relatively thick and require rigidity have higher strength of the material plate and shock absorption at the time of vehicle collision = pressure resistance It is necessary to newly provide a fracture property (also referred to as a crush property or a crush property).
前記バンパ補強材やドアビームなどの自動車構造部材のうちの、高強度な補強材としては、JIS乃至AA7000系アルミニウム合金を熱間押出加工して製造される押出形材が、素材として既に汎用されている。これに対して、フレーム、ピラーなどの大型の構造部材は、鋳塊を均熱処理後に熱間圧延する、あるいは更に冷間圧延するような、常法によって製造される圧延板を素材とすることが好ましい。ただ、前記した7000系アルミニウム合金は、圧延板としては、その高合金ゆえのつくりにくさがあり、これまであまり実用化されていない。   Among high-strength reinforcing materials among automotive structural members such as bumper reinforcing materials and door beams, extruded shapes produced by hot extrusion of JIS or AA7000 series aluminum alloys are already widely used as raw materials. Yes. On the other hand, large structural members such as frames and pillars may be made of a rolled plate manufactured by a conventional method such as hot rolling after soaking or further cold rolling the ingot. preferable. However, the above-mentioned 7000 series aluminum alloy is difficult to make as a rolled plate because of its high alloy, and has not been practically used so far.
このため、通常の圧延(常法)によって製造される圧延板用の合金としては、前記7000系よりも低合金であるがゆえに作りやすい、Al−Mg−Si系アルミニウム合金であるJIS乃至AA6000系アルミニウム合金が注目される。   For this reason, as an alloy for a rolled sheet manufactured by normal rolling (ordinary method), it is an Al—Mg—Si based aluminum alloy that is easy to make because it is a lower alloy than the 7000 series, and JIS to AA6000 series. Aluminum alloys are noted.
この6000系アルミニウム合金板は、自動車の大型ボディパネル(フード、フェンダー、ドア、ルーフ、トランクリッドなどのアウタパネルやインナパネル)としては既に用いられている。
このため、これら自動車の大型ボディパネルに要求される、曲げ加工性やヘム加工性などを含むプレス成形性と、室温時効抑制を含むBH性(ベークハード性)などの特性向上のために、従来から、成分組成や、板の表面と板厚方向の板内部でのCube方位などの集合組織を特に規定するなどの冶金的な改善策が、数多く提案されている。
This 6000 series aluminum alloy plate is already used as a large body panel (outer panel or inner panel such as a hood, fender, door, roof, trunk lid, etc.) of an automobile.
Therefore, in order to improve characteristics such as press formability including bending workability and hem workability and BH property (bake hardness) including room temperature aging control, which are required for these large body panels of automobiles. Therefore, many metallurgical improvement measures have been proposed, such as defining the composition of the components and the texture such as the Cube orientation in the plate surface and in the plate thickness direction.
この集合組織の規定の代表例として、例えば、特許文献1では、BH性が優れ、板製造後の室温時効が少なく、長期間放置した場合でも自然時効による硬化に起因する成形性の低下も少なく、さらには良好な成形加工性(曲げ加工性、ヘム加工性)を有すると同時に、曲げ異方性も少なく、また成形加工時にリジングマークも抑制され、耐粒界腐食性にも優れた成形加工用アルミニウム合金板を、量産的規模で確実かつ安定して低コストで製造し得る方法が提案されている。
具体的には、特定組成の6000系アルミニウム合金からなり、板表面から板厚の1/10の位置のキューブ方位密度と板表面から板厚の1/4の位置のキューブ方位密度との平均値が、板表面から板厚の1/2の位置(板厚方向中心位置)のキューブ方位密度よりも高い関係となるようにするなど、均質処理、熱間圧延、溶体化処理条件などを特定の範囲として制御している。
As a typical example of the provision of this texture, for example, in Patent Document 1, the BH property is excellent, the room temperature aging after producing the plate is small, and even when left for a long time, there is little decrease in formability due to hardening due to natural aging. In addition, it has excellent forming processability (bending processability, hemming processability), has low bending anisotropy, suppresses ridging marks during forming process, and has excellent intergranular corrosion resistance. There has been proposed a method capable of manufacturing an aluminum alloy plate for industrial use reliably and stably at a low cost on a mass production scale.
Specifically, it is made of a 6000 series aluminum alloy having a specific composition, and is an average value of a cube orientation density at a position 1/10 of the plate thickness from the plate surface and a cube orientation density at a position 1/4 of the plate thickness from the plate surface. However, specific conditions such as homogenization treatment, hot rolling, solution treatment conditions, etc. are specified such that the relationship is higher than the cube orientation density at a position 1/2 the plate thickness (center position in the plate thickness direction) from the plate surface. Control as a range.
ただ、本発明が対象とする、前記したフレーム、ピラーなどの自動車構造部材では、前記特許文献1などの自動車パネル構造部材用途とは異なり、更に高強度化させることと、車体衝突時の衝撃吸収性=耐圧壊性を新たに持たせるなどの、この構造部材用途特有の新たな特性が要求される。   However, the above-described automotive structural members such as frames and pillars, which are the subject of the present invention, are different from the automotive panel structural member uses described in Patent Document 1 and the like, and are further enhanced in strength and shock absorption at the time of a vehicle collision. A new characteristic peculiar to the use of the structural member is required, such as a new property = breakdown resistance.
この一例として、近年の自動車の衝突安全基準のレベルアップ(厳格化)によって、ヨーロッパなどでは、前記フレーム、ピラーなどの自動車構造部材に、ドイツ自動車工業会(VDA)で規格化されている「VDA238−100 Plate bending test for metallic materials(以後、VDA曲げ試験と言う)」にて評価される、自動車の衝突時における衝撃吸収性(耐圧壊性、圧壊特性)を満たすことが求められるようになっている。   As an example of this, in recent years, due to the level-up (strictening) of crash safety standards for automobiles, in Europe and the like, the automobile structural members such as the frames and pillars are standardized by the German Automobile Manufacturers Association (VDA) “VDA238. -100 Plate Bending Test for Metallic Materials (hereinafter referred to as VDA bending test), which is required to satisfy the impact absorption (crush resistance, crushing characteristics) at the time of automobile collision. Yes.
このような厳しい安全基準に対して、前記した従来の自動車パネル用に板の表面と内部での集合組織を制御した6000系アルミニウム合金板では、自動車構造部材とした場合に、共通して、より高強度化させた上での耐圧壊性が不足している問題がある。   With respect to such strict safety standards, the 6000 series aluminum alloy plate in which the texture and the texture inside the plate are controlled for the above-described conventional automobile panel, more commonly in the case of an automobile structural member, There is a problem that the pressure-breaking resistance is insufficient after increasing the strength.
これに対して、特許文献2では、6000系アルミニウム合金板に、Snを新たに添加するとともに、この板の結晶粒界に存在する、円相当径が0.2〜10μmの範囲のSn系化合物の平均数密度を0.4個/μm以下(0個/μmを含む)に制御することが提案されている。
そして、このアルミニウム合金板を溶体化・焼き入れ処理および人工時効処理した後の(自動車構造部材としての)特性として、200MPa以上の0.2%耐力を有するとともに、VDA曲げ試験にて75°以上の曲げ角度となる圧壊特性を有するとしている。
On the other hand, in Patent Document 2, Sn is newly added to a 6000 series aluminum alloy plate, and an Sn series compound having an equivalent circle diameter in the range of 0.2 to 10 μm is present at the crystal grain boundary of this plate. It has been proposed to control the average number density of these to 0.4 pieces / μm 3 or less (including 0 pieces / μm 3 ).
The aluminum alloy sheet has 0.2% proof stress of 200 MPa or more as a characteristic (as an automobile structural member) after solution treatment / quenching treatment and artificial aging treatment, and 75 ° or more in a VDA bending test. It is said that it has the crushing characteristic which becomes the bending angle of.
特許第4602195号公報Japanese Patent No. 4602195 特開2016−160516号公報Japanese Patent Laid-Open No. 2006-160516
ただ、特許文献2のように、Snを新たに必要量添加すると、加工性が低下するなど、圧延板が作りにくくなる問題があり、製造工程や製造条件を変える必要も生じるので、できればSnの添加は避けたい。しかし、前記した通り、従来の6000系アルミニウム合金板の集合組織などの組織制御では、自動車構造部材としての強度と耐圧壊性の向上には大きな限界があった。   However, as in Patent Document 2, when a necessary amount of Sn is newly added, there is a problem that it becomes difficult to make a rolled plate, such as a decrease in workability, and it is also necessary to change the manufacturing process and manufacturing conditions. I want to avoid the addition. However, as described above, in the conventional structure control such as a texture of a 6000 series aluminum alloy plate, there is a great limit to the improvement of strength and pressure resistance as an automobile structural member.
したがって、6000系アルミニウム合金板からなる構造部材(以下、単に6000系アルミニウム合金構造部材とも言う)をより高強度化させた上で耐圧壊性も向上させることには、未だ開発の余地がある。   Therefore, there is still room for development in order to increase the strength of a structural member made of a 6000 series aluminum alloy plate (hereinafter also simply referred to as a 6000 series aluminum alloy structural member) and to improve the pressure resistance.
本発明では、このような事情に着目してなされたものであり、強度と耐圧壊性(衝撃吸収性)とを向上させた6000系アルミニウム合金構造部材を得るための、素材6000系アルミニウム合金板および、この素材6000系アルミニウム合金板を用いた前記構造部材の製造方法を提供することを目的とする。

The present invention has been made paying attention to such circumstances, and is a raw material 6000 series aluminum alloy plate for obtaining a 6000 series aluminum alloy structural member having improved strength and pressure resistance (shock absorption). And it aims at providing the manufacturing method of the said structural member using this raw material 6000 series aluminum alloy plate.

この目的を達成するための、構造部材用アルミニウム合金板の実施形態は、上記アルミニウム合金構造部材用のアルミニウム合金板であって、Mg:0.3〜1.5質量%、Si:0.3〜1.5質量%を含有し、残部がAlおよび不可避的不純物からなるAl−Mg−Si系アルミニウム合金からなるとともに、板厚が2mm以上、5mm以下であり、SEM−EBSD法により測定された集合組織として、板表面の5mm×5mmの矩形領域におけるCube方位の平均面積率が20%以上であるとともに、板厚の1/4厚さ位置における前記板表面と平行な面の5mm×5mmの矩形領域におけるCube方位の平均面積率が25%以上で、かつ、前記板表面のCube方位の平均面積率よりも、板厚の1/4厚さ位置におけるCube方位の平均面積率の方が大きいことである。   In order to achieve this object, an embodiment of an aluminum alloy plate for a structural member is the aluminum alloy plate for an aluminum alloy structural member, and Mg: 0.3 to 1.5 mass%, Si: 0.3 Containing ~ 1.5 mass%, the balance is made of Al-Mg-Si based aluminum alloy consisting of Al and inevitable impurities, and the plate thickness is 2 mm or more and 5 mm or less, measured by SEM-EBSD method As a texture, the average area ratio of Cube orientation in a rectangular region of 5 mm × 5 mm on the plate surface is 20% or more, and 5 mm × 5 mm of a plane parallel to the plate surface at a ¼ thickness position of the plate thickness The average area ratio of the Cube orientation in the rectangular region is 25% or more, and the Cube orientation at the 1/4 thickness position of the plate thickness is larger than the average area ratio of the Cube orientation on the plate surface. The average area ratio of the azimuth is larger.
また、前記目的を達成するための、アルミニウム合金構造部材の製造方法の実施形態は、上記アルミニウム合金板に、5〜15%の予ひずみを付加した上で、プレス成形して構造部材となし、この構造部材を人工時効処理することによって、前記構造部材表面の5mm×5mmの矩形領域におけるCube方位の平均面積率が25%以上であるとともに、前記構造部材の厚みの1/4厚さ位置における前記構造部材表面と平行な面の5mm×5mmの矩形領域におけるCube方位の平均面積率が30%以上で、かつ、前記構造部材表面のCube方位の平均面積率よりも、前記構造部材の厚みの1/4厚さ位置におけるCube方位の平均面積率の方が大きい集合組織とし、前記人工時効処理後の構造部材が220MPa以上の0.2%耐力と、VDA曲げ試験にて80°以上の曲げ角度となる圧壊特性とを有するようにしたことである。   An embodiment of a method for producing an aluminum alloy structural member for achieving the above object is to form a structural member by press forming after adding a pre-strain of 5 to 15% to the aluminum alloy plate, By subjecting this structural member to artificial aging treatment, the average area ratio of the Cube orientation in a rectangular region of 5 mm × 5 mm on the surface of the structural member is 25% or more, and at the 1/4 thickness position of the thickness of the structural member. The average area ratio of the Cube orientation in a rectangular area of 5 mm × 5 mm of the plane parallel to the surface of the structural member is 30% or more, and the thickness of the structural member is larger than the average area ratio of the Cube orientation of the structural member surface. A texture having a larger average area ratio of the Cube orientation at the 1/4 thickness position is 0.2% proof stress of the structural member after the artificial aging treatment is 220 MPa or more. Is that you have a crush properties that make VDA bending than 80 ° of bending angle in the test.
本発明者は、構造部材をより高強度化させた上で耐圧壊性を向上させるための、素材である6000系アルミニウム合金板の集合組織について検討した。
その結果、前記アルミニウム合金板が、本発明の実施形態に係る構造部材用アルミニウム合金板で規定する板厚方向および、本発明の実施形態に係る、アルミニウム合金構造部材の製造方法で規定する板の面方向の分布など、特定のCube方位の集合組織を有する場合には、より多くの予ひずみを付加された上で、構造部材としての人工時効処理を施されると、前記特定の集合組織がより発達して、構造部材の高強度化と耐圧壊性の向上が図れることを知見した。
The present inventor examined the texture of a 6000 series aluminum alloy plate as a material for improving the pressure resistance after making the structural member stronger.
As a result, the aluminum alloy plate has a plate thickness direction defined by the aluminum alloy plate for structural members according to the embodiment of the present invention, and a plate defined by the method for manufacturing an aluminum alloy structural member according to the embodiment of the present invention. In the case of having a texture of a specific Cube orientation such as a distribution in the plane direction, when the artificial aging treatment as a structural member is performed after adding more pre-strain, the specific texture is It has been found that the structural member can be further strengthened and the strength of the structural member can be improved and the pressure resistance can be improved.
すなわち、素材である6000系アルミニウム合金板の集合組織として、特にCube方位の、板厚方向および板の面方向の分布を各々制御した場合、この素材板に、より多くの予ひずみを付加した上で、構造部材としての人工時効処理を施すと、構造部材の厚み方向でのCube方位がより発達するとともに、構造部材の面方向においても、局所的にCube方位の面積率が低い箇所を無くして、Cube方位の面積率の均一化を図ることが可能となる。
このため、構造部材としての強度と曲げ性(耐圧壊性)のバランスが向上して、高強度化と耐圧壊性(衝撃吸収性)の向上が図れることとなる。
That is, as the texture of the material 6000 series aluminum alloy plate, particularly when the distribution of the Cube orientation in the plate thickness direction and the plate surface direction is controlled, more pre-strain is added to the material plate. Then, when artificial aging treatment as a structural member is performed, the Cube orientation in the thickness direction of the structural member is further developed, and even in the surface direction of the structural member, there is no portion where the area ratio of the Cube orientation is locally low. It becomes possible to make the area ratio of the Cube orientation uniform.
For this reason, the balance between strength and bendability (breakdown resistance) as a structural member is improved, and the strength can be increased and the breakup resistance (shock absorption) can be improved.
これによって、素材である6000系アルミニウム合金板の集合組織が、人工時効処理後の構造部材の高強度化と耐圧壊性の向上が図れる集合組織ほどには、Cube方位が十分発達していなかったとしても、このような素材6000系アルミニウム合金板を用いて、人工時効処理後の高強度化と耐圧壊性の向上が図れるCube方位が十分発達した集合組織の構造部材とすることが可能となる。
このため、構造部材の素材である6000系アルミニウム合金板の、Cube方位を十分発達させるための、製造工程や製造条件の特別な付加や変更が不要となり、板の製造にかかる負荷を大きく減らすことが可能となる。
As a result, the Cube orientation was not sufficiently developed so that the texture of the 6000 series aluminum alloy plate as the material could increase the strength of the structural member after the artificial aging treatment and improve the pressure fracture resistance. However, by using such a material 6000 series aluminum alloy plate, it becomes possible to make a structural member having a sufficiently developed Cube orientation capable of increasing the strength and improving the fracture resistance after artificial aging treatment. .
This eliminates the need for special additions and changes in the manufacturing process and manufacturing conditions for sufficiently developing the Cube orientation of the 6000 series aluminum alloy plate, which is the material of the structural member, and greatly reduces the load on plate manufacturing. Is possible.
以下に、本発明の実施態様について、要件毎に具体的に説明する。
本発明では、剛性が要求される自動車構造部材用であって、筒状などの複雑な立体形状を有し、素材であるアルミニウム合金板(圧延板)をプレス成形して得られる、板の成形体からなる自動車構造部材などの構造部材を主たる用途としている。したがって、以下の説明では、構造部材のうちでも、この自動車構造部材を意図して説明する。しかし、本発明は自動車構造部材に限定されるものでなく、他の構造部材に用いてよい。
Hereinafter, embodiments of the present invention will be specifically described for each requirement.
In the present invention, for automobile structural members that require rigidity, forming a plate having a complicated three-dimensional shape such as a cylindrical shape and obtained by press-forming an aluminum alloy plate (rolled plate) as a material Main uses are structural members such as automobile structural members made of body. Therefore, in the following description, among the structural members, this automobile structural member will be described. However, the present invention is not limited to automobile structural members, and may be used for other structural members.
厚み、板厚:
6000系アルミニウム合金板の実施態様として、板厚は2mm以上、5mm以下とする。厚みあるいは板厚が2mm未満では、構造部材としての強度や剛性が不足する。また、板厚が5mmを超えた場合には、板厚が厚すぎるため、素材のアルミニウム合金板の構造部材へのプレス成形ができなくなる。また、構造材として、鋼板や鋼材に代替されるべき、アルミニウム合金による軽量化の効果が損なわれる。なお、以下の説明では、構造部材の厚みや素材のアルミニウム合金板の板厚を、まとめて厚みあるいは板厚と言う。
Thickness, plate thickness:
As an embodiment of the 6000 series aluminum alloy plate, the plate thickness is 2 mm or more and 5 mm or less. When the thickness or the plate thickness is less than 2 mm, the strength and rigidity as a structural member are insufficient. Further, when the plate thickness exceeds 5 mm, the plate thickness is too thick, so that it is impossible to press-form the material aluminum alloy plate to the structural member. Moreover, the effect of weight reduction by an aluminum alloy which should be replaced with a steel plate or steel as a structural material is impaired. In the following description, the thickness of the structural member and the thickness of the aluminum alloy plate of the material are collectively referred to as thickness or plate thickness.
アルミニウム合金組成:
6000系アルミニウム合金板の化学成分組成の実施態様について、以下に説明する。
6000系アルミニウム合金板の化学成分組成は、前記自動車構造部材などの構造部材としての、あるいは構造部材用としての素材板の、成形性やBH性を含めた強度、耐圧壊性を組成面から満足し、しかも常法での圧延による板の製造条件を大きく変えないことを前提とする、なお、各元素の含有量の%表示は全て質量%の意味である。
このためのアルミニウム合金板の化学成分組成は、Al−Mg−Si系アルミニウム合金として、Mg:0.3〜1.5質量%、Si:0.3〜1.5質量%を含有し、残部がAlおよび不可避的不純物からなるものとする。
この組成に、更に、Cu:0.001〜0.7質量%、Mn:0.05〜0.5質量%、Zr:0.04〜0.20質量%、Cr:0.04〜0.20質量%、Sc:0.02〜0.1質量%、Ag:0.01〜0.2質量%、Sn:0.001〜0.1質量%の一種または二種以上を含有しても良い。
Aluminum alloy composition:
The embodiment of the chemical component composition of the 6000 series aluminum alloy sheet will be described below.
The chemical composition of the 6000 series aluminum alloy plate satisfies the composition and strength of the material plate as a structural member such as the automobile structural member or the structural member, including the formability and BH property, from the viewpoint of composition. In addition, it is assumed that the manufacturing conditions of the plate by rolling by a conventional method are not greatly changed. Note that the% display of the content of each element means mass%.
The chemical composition of the aluminum alloy plate for this purpose includes, as an Al—Mg—Si based aluminum alloy, Mg: 0.3 to 1.5 mass%, Si: 0.3 to 1.5 mass%, and the balance Is made of Al and inevitable impurities.
In addition to this composition, Cu: 0.001-0.7 mass%, Mn: 0.05-0.5 mass%, Zr: 0.04-0.20 mass%, Cr: 0.04-0. 20% by mass, Sc: 0.02-0.1% by mass, Ag: 0.01-0.2% by mass, Sn: 0.001-0.1% by mass good.
Si:0.3〜1.5質量%
SiはMgとともに、固溶強化と、塗装焼き付け処理などの人工時効処理時に、強度向上に寄与する時効析出物を形成して、時効硬化能を発揮し、自動車の構造材として必要な強度(耐力)を得るための必須の元素である。
Si含有量が0.3質量%未満では、Si含有量が少なすぎ、塗装焼付け処理前(人工時効処理前)の固溶Si量が減少し、時効析出物の生成量が不足するため、BH性が著しく低下し、強度が不足する。
一方、Si含有量が1.5質量%を超えて多すぎると、板の製造時に粗大な化合物を形成し、延性を劣化させる。従って、Si含有量は0.3〜1.5質量%、好ましくは0.7〜1.4質量%の範囲とする。
Si: 0.3 to 1.5% by mass
Si, together with Mg, forms an aging precipitate that contributes to strength improvement during solid solution strengthening and artificial aging treatment such as paint baking treatment, exhibits age-hardening ability, and strength (proof strength) required for automobile structural materials ) Is an essential element for obtaining.
If the Si content is less than 0.3% by mass, the Si content is too small, the amount of dissolved Si before paint baking (before artificial aging) decreases, and the amount of aging precipitates generated is insufficient. The properties are significantly reduced and the strength is insufficient.
On the other hand, if the Si content exceeds 1.5% by mass, a coarse compound is formed during the production of the plate, and ductility is deteriorated. Accordingly, the Si content is in the range of 0.3 to 1.5 mass%, preferably 0.7 to 1.4 mass%.
Mg:0.3〜1.5質量%
Mgも、Siとともに、固溶強化と、塗装焼き付け処理などの人工時効処理時に、Siとともに強度向上に寄与する時効析出物を形成して、時効硬化能を発揮し、自動車の構造材としての必要耐力を得るための必須の元素である。
Mg含有量が0.3質量%未満では、Mg含有量が少なすぎ、塗装焼付け処理前(人工時効処理前)の固溶Si量が減少し、時効析出物の生成量が不足するため、BH性が著しく低下し、強度が不足する。
一方、Mg含有量が1.5質量%を超えて多すぎると、板の冷間圧延時にせん断帯が形成されやすくなり、割れの原因となる。従って、Mg含有量は0.3〜1.5質量%、好ましくは0.4〜1.2質量%の範囲とする。
Mg: 0.3 to 1.5% by mass
Mg, together with Si, forms aging precipitates that contribute to strength improvement with Si during solid solution strengthening and artificial aging treatment such as paint baking treatment, and exhibits age-hardening ability and is necessary as a structural material for automobiles It is an essential element for obtaining proof stress.
If the Mg content is less than 0.3% by mass, the Mg content is too small, the amount of dissolved Si before paint baking treatment (before artificial aging treatment) decreases, and the amount of aging precipitates produced is insufficient. The properties are significantly reduced and the strength is insufficient.
On the other hand, if the Mg content exceeds 1.5% by mass, a shear band is easily formed during cold rolling of the plate, which causes cracking. Therefore, the Mg content is in the range of 0.3 to 1.5 mass%, preferably 0.4 to 1.2 mass%.
Cu、Mn、Zr、Cr、Sc、Ag、Snの一種または二種以上
Cu、Mn、Zr、Cr、Sc、Ag、Snは、共通して、素材板および構造部材を高強度化させる効果があるので、広い意味で同効元素と見なせるが、その具体的な機構には、共通する部分も、異なる部分も勿論ある。
One or more of Cu, Mn, Zr, Cr, Sc, Ag, Sn Cu, Mn, Zr, Cr, Sc, Ag, Sn are commonly effective in increasing the strength of the material plate and the structural member. It can be regarded as a synergistic element in a broad sense, but there are, of course, common parts and different parts in its specific mechanism.
Cuは、固溶強化にて強度の向上に寄与する他、人工時効処理に際して、構造部材の時効硬化を促進して強度の向上に寄与する効果も有する。選択的に含有させる場合に、Cuのこのような効果を得るためには、0.001質量%以上含むことが好ましい。一方、Cuの含有量が多過ぎると、耐食性を劣化させるおそれがあり、好ましくない。そのため、Cu含有量は、0.7質量%以下が好ましい。
また、製品への予ひずみ付与と人工時効処理の制御によって、構造部材や板の表面のCube方位の面積率をさらに増大させる場合は、Cu含有量は、好ましくは0.3質量%以下、更に好ましくは0.2質量%以下とする。Cu含有量が0.3質量%、より厳しくは0.2質量%を越えると、アルミマトリックス中に固溶するCu濃度が増大し、それが予ひずみ付与時のCube方位粒へのひずみ蓄積を増大させる方向に働き、人工時効処理後のCube方位粒の成長、面積率の増大の効果を妨げる可能性がある。
In addition to contributing to strength improvement by solid solution strengthening, Cu also has the effect of promoting age hardening of the structural member and contributing to strength improvement during artificial aging treatment. In order to acquire such an effect of Cu, when containing selectively, it is preferable to contain 0.001 mass% or more. On the other hand, when there is too much content of Cu, there exists a possibility that corrosion resistance may deteriorate, and it is unpreferable. Therefore, the Cu content is preferably 0.7% by mass or less.
In addition, when further increasing the area ratio of the Cube orientation of the surface of the structural member or plate by applying pre-strain to the product and controlling the artificial aging treatment, the Cu content is preferably 0.3% by mass or less, Preferably it is 0.2 mass% or less. If the Cu content exceeds 0.3% by mass, more strictly 0.2% by mass, the concentration of Cu dissolved in the aluminum matrix increases, which causes strain accumulation in the Cube-oriented grains during prestraining. There is a possibility that it works in the direction of increasing and hinders the effects of the growth of the Cube-oriented grains and the increase of the area ratio after the artificial aging treatment.
Mn、Zr、Cr、Scは、鋳塊及び板の結晶粒を微細化して強度を向上させる。これらの含有量が各々下限値未満では、その効果が不足する。一方、これらの含有量が多すぎ、それぞれの上限値を超えた場合には、粗大な化合物を形成して、衝撃吸収性(圧壊特性)を劣化させる。
したがって、選択的に含有させる場合には、Mn:0.05〜0.5質量%、Zr:0.04〜0.20質量%、Cr:0.04〜0.20質量%、Sc:0.02〜0.1質量%の各範囲とする。
Mn, Zr, Cr, and Sc refine crystal grains of the ingot and the plate to improve the strength. If each of these contents is less than the lower limit, the effect is insufficient. On the other hand, when these contents are too large and exceed the respective upper limit values, a coarse compound is formed, and the impact absorbability (crush characteristics) is deteriorated.
Therefore, when selectively contained, Mn: 0.05 to 0.5% by mass, Zr: 0.04 to 0.20% by mass, Cr: 0.04 to 0.20% by mass, Sc: 0 The range is 0.02 to 0.1% by mass.
Agは、構造材への成形加工(プレス成形)後の人工時効処理によって強度向上に寄与する時効析出物を緊密微細に析出させ、高強度化を促進する効果があるので、必要に応じて選択的に含有させる。Agの含有量が0.01%未満では強度向上効果が小さい。一方、Ag含有量が多すぎると、圧延性及び溶接性などの諸特性を却って低下させ、また、強度向上効果も飽和し、高価となるだけである。従って、含有させる場合のAgの含有量は0.01〜0.2質量%の範囲とする。   Ag is selected as needed because it has the effect of closely and finely precipitating aging precipitates that contribute to strength improvement by artificial aging treatment after forming processing (press molding) into a structural material, thereby promoting high strength. To be included. If the Ag content is less than 0.01%, the effect of improving the strength is small. On the other hand, if the Ag content is too large, various properties such as rollability and weldability are deteriorated, and the effect of improving the strength is saturated and only expensive. Accordingly, the Ag content in the case of inclusion is in the range of 0.01 to 0.2% by mass.
Snは室温でのクラスタ形成を抑制して、溶体化・焼き入れ処理後の板の、優れた成形加工性を長時間保持する効果を有し、更にその後に焼付け塗装処理などの人工時効処理した場合の構造部材の強度を向上させる。Sn含有量が0.001%未満ではその効果が小さく、また0.1%を超えても、その効果は飽和し、却って熱間脆性を生じて熱間加工性(熱延性)を著しく劣化させる。従って、含有させる場合のSnの含有量は0.001〜0.1質量%の範囲とする。   Sn has the effect of suppressing the cluster formation at room temperature and maintaining the excellent formability of the plate after solution treatment and quenching treatment for a long time, and further subjected to artificial aging treatment such as baking coating treatment after that. The strength of the structural member in the case is improved. If the Sn content is less than 0.001%, the effect is small, and if it exceeds 0.1%, the effect is saturated, and on the other hand, hot embrittlement occurs and the hot workability (hot ductility) is remarkably deteriorated. . Therefore, the Sn content in the case of inclusion is in the range of 0.001 to 0.1% by mass.
その他の元素:
これら記載した以外の、Ti、B、Fe、Zn、Vなどのその他の元素は不可避的な不純物であり、6000系合金としてJIS規格などで規定する範囲での各々の含有を許容する。
Other elements:
Other elements such as Ti, B, Fe, Zn, and V other than those described above are unavoidable impurities, and are allowed to be contained within the range specified by the JIS standard as a 6000 series alloy.
集合組織:
以上の厚みや組成を前提として、本発明では、構造部材用の6000系アルミニウム合金板の、特にCube方位の、板厚方向および面方向の分布を各々制御することで、構造部材とされた場合の強度と曲げ性(耐圧壊性)のバランスを向上させる。
Texture:
On the premise of the above thickness and composition, in the present invention, by controlling the distribution of the 6000 series aluminum alloy plate for the structural member, particularly in the Cube orientation, in the plate thickness direction and the surface direction, respectively, the structural member is used. Improves the balance between strength and bendability (crush resistance).
(Cube方位の厚み方向の分布制御)
このために、先ず、素材板のSEM−EBSD法により測定された集合組織として、板表面の5mm×5mmの矩形領域におけるCube方位の平均面積率を20%以上とするとともに、前記素材板の板厚の1/4厚さ位置における前記板表面と平行な面の5mm×5mmの矩形領域におけるCube方位の平均面積率を25%以上で、かつ、前記板表面のCube方位の平均面積率よりも、前記素材板の板厚の1/4厚さ位置におけるCube方位の平均面積率の方を大きくする。ここで、本発明で言う矩形領域とは、平面的に矩形の領域、または矩形な平面領域の意味である。
(Cube orientation distribution control in the thickness direction)
For this purpose, first, as the texture measured by the SEM-EBSD method of the material plate, the average area ratio of the Cube orientation in a rectangular area of 5 mm × 5 mm on the surface of the plate is set to 20% or more, and the plate of the material plate The average area ratio of the Cube orientation in a rectangular region of 5 mm × 5 mm of a plane parallel to the plate surface at a 1/4 thickness position is 25% or more, and is more than the average area ratio of the Cube orientation on the plate surface The average area ratio of the Cube orientation at the 1/4 thickness position of the thickness of the material plate is increased. Here, the rectangular area referred to in the present invention means a rectangular area in a plane or a rectangular plane area.
これが、6000系アルミニウム合金板を構造部材とした場合の、人工時効処理後の構造部材の集合組織を、高強度化と耐圧壊性(衝撃吸収性)の向上が図れるCube方位が発達した集合組織とするための必要条件となる。   When a 6000 series aluminum alloy plate is used as the structural member, the texture of the structural member after the artificial aging treatment is a texture in which the Cube orientation has been developed so as to increase the strength and improve the puncture resistance (shock absorption). This is a necessary condition.
ここで、構造部材としての高強度と耐圧壊性(衝撃吸収性)との兼備を保障するためには、構造部材のCube方位が発達した集合組織として、表面の5mm×5mmの矩形領域におけるCube方位の平均面積率が25%以上であるとともに、構造部材の厚みの1/4厚さ位置における構造部材の前記表面と平行な面の5mm×5mmの矩形領域におけるCube方位の平均面積率が30%以上であることが好ましい。そして、これに加えて、構造部材の前記表面のCube方位の平均面積率よりも、前記構造部材の厚みの1/4厚さ位置におけるCube方位の平均面積率の方が大きいことが好ましい。   Here, in order to ensure the combination of high strength and pressure proof fracture (impact absorbability) as a structural member, as a texture in which the Cube orientation of the structural member is developed, a Cube in a rectangular region of 5 mm × 5 mm on the surface is used. The average area ratio of orientation is 25% or more, and the average area ratio of Cube orientation in a rectangular region of 5 mm × 5 mm of a plane parallel to the surface of the structural member at a thickness of 1/4 of the thickness of the structural member is 30. % Or more is preferable. In addition to this, it is preferable that the average area ratio of the Cube orientation at the 1/4 thickness position of the thickness of the structural member is larger than the average area ratio of the Cube orientation of the surface of the structural member.
Cube方位を発達させた構造部材の場合、Cube方位の厚み方向の分布が、耐圧壊性=前記VDA曲げ性に与える影響を解析した結果、構造部材あるいは板の表面のCube方位粒よりも、1/4厚さ位置のCube方位(1/4t部)粒の方が耐圧壊性の向上に大きく寄与する。
すなわち、耐圧壊性の向上には、板の板厚の1/4厚さ位置における板表面と平行な面の5mm×5mmの矩形領域におけるCube方位(以下、単に1/4t部のCube方位とも言う)の面積率の方が、前記板表面の5mm×5mmの矩形領域におけるCube方位(以下、単に表面のCube方位とも言う)よりも大きく寄与する。
これは、車体衝突などの荷重負荷により、自動車構造部材として使用中の構造部材の表面に微小クラックが形成されても、この構造部材の1/4t部のCube方位が、そのクラックの進展を阻止する効果を持つからである。
この事実は、1/4t部のCube方位が必要量存在すれば、表面のCube方位が、1/4t部のCube方位よりも多くなくても、耐圧壊性が向上し、1/4t部のCube方位が少なくなって不足すれば、表面のCube方位をいくら多くしても、耐圧壊性が向上しないことを意味する。
In the case of a structural member in which the Cube orientation is developed, as a result of analyzing the influence of the distribution in the thickness direction of the Cube orientation on the fracture resistance = the VDA bendability, the result is 1 than the Cube orientation grain on the surface of the structural member or the plate. The Cube orientation (1 / 4t part) grains at the / 4 thickness position greatly contribute to the improvement of the pressure resistance.
That is, in order to improve the fracture resistance, the Cube orientation in a rectangular area of 5 mm × 5 mm of a plane parallel to the plate surface at the 1/4 thickness position of the plate thickness (hereinafter, simply referred to as a 1/4 t portion Cube orientation). The area ratio of (say) contributes more than the Cube orientation (hereinafter also simply referred to as the Cube orientation of the surface) in a 5 mm × 5 mm rectangular region on the plate surface.
This is because even if a micro crack is formed on the surface of a structural member that is being used as an automobile structural member due to a load such as a vehicle body collision, the 1/4 direction Cube orientation of this structural member prevents the crack from progressing. It is because it has the effect to do.
This fact indicates that if the required amount of 1/4 direction Cube orientation is present, the fracture resistance is improved even if the surface Cube orientation is not larger than the 1/4 t portion Cube orientation. If the Cube orientation is decreased and insufficient, it means that no matter how much the Cube orientation on the surface is increased, the pressure-breakdown resistance is not improved.
(Cube方位の発達)
6000系アルミニウム合金板の集合組織として、本発明のように、特にCube方位の、板厚方向、あるいは後述する板の面方向の分布を各々制御した場合、この素材板に、より多くの予ひずみを付加した上で、構造部材としての人工時効処理を施すと、構造部材の厚み方向でのCube方位がより発達するとともに、構造部材の面方向においても、局所的にCube方位の面積率が低い箇所を無くして、Cube方位の面積率の均一化を図ることが可能となる。
(Development of Cube orientation)
As the texture of the 6000 series aluminum alloy plate, as in the present invention, when the distribution of the Cube orientation, the plate thickness direction, or the plane direction of the plate to be described later is controlled, more prestrain When an artificial aging treatment is applied as a structural member, the Cube orientation in the thickness direction of the structural member is further developed, and the area ratio of the Cube orientation is also locally low in the plane direction of the structural member It is possible to make the area ratio of the Cube orientation uniform by eliminating the portions.
これは、素材である6000系アルミニウム合金板を、前記規定するCube方位が発達した集合組織とした場合には、より多くの予ひずみを付加された上で、構造部材として人工時効処理を施されると、前記特定の集合組織がより発達するからである。
溶体化処理などの調質後の素材板にはひずみが無いが、このひずみが無い素材板に対して、冷間加工によって新たに特定のひずみを付加した上で、更に特定条件下で人工時効処理すると、Cube方位粒の粒成長、粗大化による、構造部材の表面のCube方位や、1/4t部のCube方位の更なる増大が可能である。
溶体化処理などの調質後のひずみが無い素材板に対して、冷間加工の手段によって、新たにひずみを付加すると、ひずみが蓄積されにくいCube方位粒と、ひずみが蓄積されやすい非Cube方位粒との間に、蓄積ひずみ差がつく。この状態で、人工時効処理すると、人工時効処理時の熱履歴によって、ひずみが蓄積されていないCube方位粒が、周囲の蓄積ひずみ量の高い非Cube方位粒のひずみを低減させる駆動力でCube方位粒の粒界移動を促進し、Cube方位粒の粒成長や粗大化により、Cube方位の面積率の更なる増大が可能となる。
This is because, when a 6000 series aluminum alloy plate as a material is made into a texture in which the Cube orientation defined above is developed, it is subjected to artificial aging treatment as a structural member after adding more pre-strain. This is because the specific texture is further developed.
Although there is no distortion in the material plate after tempering such as solution treatment, a specific strain is newly added to the material plate without this strain by cold working, and artificial aging is further performed under specific conditions. When the treatment is performed, it is possible to further increase the Cube orientation of the surface of the structural member and the Cube orientation of the 1/4 t portion by the grain growth and coarsening of the Cube orientation grains.
When a new strain is applied to a material plate without strain after tempering such as a solution treatment by means of cold working, a Cube orientation grain in which strain is difficult to accumulate and a non-Cube orientation in which strain is likely to accumulate. There is a difference in accumulated strain between the grains. In this state, when the artificial aging treatment is performed, the Cube orientation grains in which strain is not accumulated due to the thermal history at the time of the artificial aging treatment is reduced by the driving force that reduces the strain of the surrounding non-Cube orientation grains having a high accumulated strain amount. The grain boundary movement of the grains is promoted and the area ratio of the Cube orientation can be further increased by the grain growth and coarsening of the Cube orientation grains.
但し、このようにCube方位をより発達させる場合でも、前記した通り、6000系アルミニウム合金板表面の5mm×5mmの矩形領域におけるCube方位の平均面積率が20%以上であるとともに、前記板の板厚の1/4厚さ位置における前記板表面と平行な面の5mm×5mmの矩形領域におけるCube方位の平均面積率が25%以上で、かつ、前記板表面のCube方位の平均面積率よりも、前記板の板厚の1/4厚さ位置におけるCube方位の平均面積率の方が大きいことが、前提として必要である。
このように、ある程度以上の量のCube方位粒が予ひずみ付加前に存在していないと(Cube方位が発達していないと)、予ひずみ+人工時効処理による前記Cube方位の増加効果が現れない。
However, even when the Cube orientation is further developed in this way, as described above, the average area ratio of the Cube orientation in a 5 mm × 5 mm rectangular region on the surface of the 6000 series aluminum alloy plate is 20% or more, and the plate of the plate The average area ratio of the Cube orientation in a rectangular region of 5 mm × 5 mm of the plane parallel to the plate surface at the 1/4 thickness position is 25% or more and more than the average area ratio of the Cube orientation on the plate surface It is necessary as a premise that the average area ratio of the Cube orientation at the 1/4 thickness position of the plate thickness is larger.
Thus, if the amount of Cube orientation grains of a certain amount or more does not exist before the prestrain is added (if the Cube orientation is not developed), the effect of increasing the Cube orientation by prestrain + artificial aging treatment does not appear. .
例えば、6000系アルミニウム合金板表面のCube方位の平均面積率が20%未満か、前記板の板厚の1/4厚さ位置におけるCube方位の平均面積率が25%未満では、冷間加工(予ひずみ)と人工時効処理時との組み合わせで、前記板(素材板)が有するCube方位よりも更に発達させても、特に、構造部材の厚み方向でのCube方位の平均面積率の規定を満たせない可能性が高い。   For example, when the average area ratio of the Cube orientation on the surface of the 6000 series aluminum alloy plate is less than 20% or the average area ratio of the Cube orientation at the 1/4 thickness position of the plate thickness is less than 25%, cold working ( Even if it is further developed from the Cube orientation of the plate (material plate) by a combination of pre-strain) and artificial aging treatment, the average area ratio of the Cube orientation in the thickness direction of the structural member can be satisfied. Most likely not.
構造部材としてのCube方位を発達させるための、冷間加工による予ひずみの付与および、塗装焼付け処理などの人工時効処理の好ましい条件については、構造部材の製造方法の箇所で詳述する。   The preferable conditions for the pre-straining by cold working and the artificial aging treatment such as paint baking treatment for developing the Cube orientation as the structural member will be described in detail in the section of the manufacturing method of the structural member.
(Cube方位の面方向の分布制御)
更に、集合組織を制御する実施態様では、素材板のCube方位の面方向(表面あるいは表面と平行な方向の面)の分布制御を行うことが好ましい。
Cube方位の面方向の分布、すなわち、素材板や構造部材の表面のCube方位および1/4t部のCube方位の面方向での分布制御、言い換えるとCube方位の面方向の局所的な分布の制御が、さらなる耐圧壊性の向上につながる。
(Cube orientation distribution control in the plane direction)
Furthermore, in the embodiment for controlling the texture, it is preferable to control the distribution of the surface direction of the Cube orientation of the material plate (the surface or a surface parallel to the surface).
Control of the distribution of the Cube orientation in the plane direction, that is, the distribution control of the Cube orientation on the surface of the material plate or the structural member and the Cub orientation of the 1 / 4t portion in the plane direction, in other words, the control of the local distribution of the Cube orientation in the plane direction. However, it leads to further improvement of the pressure resistance.
素材板や構造部材のCube方位は、その面方向(素材板の幅方向あるいは長手方向)にも変動しており、平均値としてのCube方位の面積率が高くても、局所的にCube方位の面積率が低い部位が存在すると、その部位での前記微小クラックが生じやすくなり、表面の割れの発生及びその厚み方向への伝播を助長する可能性がある。
これを抑制するためには、局所的にCube方位の面積率が低い箇所を無くして、平均の面積率からの低下の度合い(ばらつき)を小さくすることが好ましく、局所的なCube方位の面積率の下限値を一定値以上に維持することが、耐圧壊性をさらに向上させる効果を発揮するために好ましい。
The Cube orientation of the material plate or the structural member also varies in the surface direction (width direction or longitudinal direction of the material plate), and even if the area ratio of the Cube orientation as the average value is high, the Cube orientation of the material plate or the structural member is locally If there is a portion with a low area ratio, the microcracks are likely to occur at the portion, which may promote the occurrence of surface cracks and propagation in the thickness direction.
In order to suppress this, it is preferable to eliminate a portion where the area ratio of the Cube orientation is locally low, and to reduce the degree of deterioration (variation) from the average area ratio. It is preferable to maintain a lower limit value of at least a certain value in order to exhibit the effect of further improving the pressure-breakdown resistance.
具体的に、素材板の場合には、アルミニウム合金板が、前記矩形領域を1000μm×1000μmの矩形領域毎に更に各々区切った際の、これら区切られた全ての箇所における、前記板の表面のCube方位の面積率の最小値が15%以上であるとともに、前記板の板厚の1/4厚さ位置における板表面と平行な面のCube方位の面積率の最小値が20%以上であることが好ましい。
これを構造部材とした場合には、前記矩形領域を1000μm×1000μmの矩形領域毎に更に各々区切った際の、これら区切られた全ての箇所における、構造部材表面のCube方位の面積率の最小値を20%以上とするとともに、前記構造部材の厚みの1/4厚さ位置におけるCube方位の面積率の最小値を25%以上とすることが好ましい。
Specifically, in the case of a material plate, when the aluminum alloy plate further divides the rectangular region into each rectangular region of 1000 μm × 1000 μm, the Cubes on the surface of the plate at all these divided portions The minimum value of the area ratio of the orientation is 15% or more, and the minimum value of the area ratio of the Cube orientation of the plane parallel to the plate surface at the 1/4 thickness position of the plate thickness is 20% or more. Is preferred.
When this is a structural member, the minimum value of the area ratio of the Cube orientation on the surface of the structural member at all of the divided areas when the rectangular area is further divided into rectangular areas of 1000 μm × 1000 μm. Is set to 20% or more, and the minimum value of the area ratio of the Cube orientation at the ¼ thickness position of the thickness of the structural member is preferably set to 25% or more.
ちなみに、従来の組織制御では、本発明のような、Cube方位の厚み方向の分布の耐圧壊性に与える影響の解析は見当たらず、このような観点での制御はされていなかった。   Incidentally, in the conventional structure control, there is no analysis of the influence of the distribution in the thickness direction of the Cube orientation on the pressure breakdown property as in the present invention, and the control from such a viewpoint has not been performed.
(集合組織の測定方法)
以上の規定する各結晶方位は、走査電子顕微鏡(Scanning Electron Microscope:SEM)または電界放出型走査電子顕微鏡(Field Emission-Scanning Electron Microscope:FE−SEM)を使用し、SEM−EBSD法によって、測定、評価する。
測定に供する試料は、構造部材あるいは素材板の任意の位置から、前記構造部材あるいは板の表面、および前記構造部材あるいは素材板の厚みの1/4厚さ位置における前記構造部材または素材板の表面と平行な面から、測定領域(5mm×5mmの矩形領域)を含む供試材を5個採取する。
そして、その供試材の表面を機械研磨、バフ研磨した後、電解研磨を行い、供試材の測定面となる表面を調製する。
(Measuring method of texture)
Each crystal orientation defined above is measured by SEM-EBSD method using a scanning electron microscope (SEM) or a field emission scanning electron microscope (FE-SEM). evaluate.
The sample to be used for the measurement is the surface of the structural member or material plate from an arbitrary position of the structural member or material plate, and the surface of the structural member or material plate at a 1/4 thickness position of the thickness of the structural member or material plate. Five test materials including a measurement region (5 mm × 5 mm rectangular region) are collected from a plane parallel to the surface.
Then, after mechanically polishing and buffing the surface of the test material, electrolytic polishing is performed to prepare a surface to be a measurement surface of the test material.
この際、構造部材の表面の場合には、表面の塗装皮膜や酸化皮膜を除去して、これら皮膜界面のアルミマトリックスを露出させて測定面とする。
また、構造部材または板の厚みの1/4厚さ位置における供試材であれば、構造部材または板の表面と平行な面を露出させて測定面とする。
これら5個の供試材のSEM−EBSD法による測定結果を平均化して、本発明で規定する各部位のCube方位の平均面積率(%)とする。
但し、前記Cube方位の面積率の最小値だけは、平均化せずに、個々の供試材あるいはその供試材の個々の測定部位の測定値のうちの最小のものを、前記Cube方位の面積率の最小値とする。
At this time, in the case of the surface of the structural member, the coating film or oxide film on the surface is removed, and the aluminum matrix at the interface of these films is exposed to form a measurement surface.
Moreover, if it is a test material in the 1/4 thickness position of the thickness of a structural member or a board, a surface parallel to the surface of a structural member or a board will be exposed, and it will be set as a measurement surface.
The measurement results by the SEM-EBSD method of these five specimens are averaged to obtain the average area ratio (%) of the Cube orientation of each part defined in the present invention.
However, only the minimum value of the area ratio of the Cube orientation is not averaged, and the smallest one of the measured values of the individual test materials or the individual measurement sites of the test materials is calculated based on the Cube orientation. The minimum value of the area ratio.
このSEM−EBSD法は、結晶方位集合組織の測定方法として汎用され、電界放出型走査電子顕微鏡(例えば、日本電子社製JSM-7000F)に、後方散乱電子回折像(EBSD: Electron Back-Scattered Diffraction Pattern:EBSD)システムを搭載した結晶方位解析法である。
SEM−EBSD法は、前記FE−SEMの鏡筒内にセットしたAl合金板の試料に、電子線を照射して、その後方散乱電子の回折パターンをEBSD装置(例えば、TSL社製のEBSD測定・解析システム:OIM(Orientation Imaging Macrograph) Data & Analysis)に取り込み、結晶方位解析をしながら試料表面を1μmおきに走査する。これにより、各点でのEBSP(Electron Back Scatter Diffraction Pattern)を得てその指数付けを行い,電子線照射部位の結晶方位を求める。得られた結晶方位測定データを圧延方向軸周りに90°回転,さらに,圧延面法線方向に90°回転操作し,測定領域全域においてEBSDによる結晶方位測定を行った際の、結晶方位分布関数(ODF)や面積率を計算し求める。これらFE−SEMにEBSDシステムを搭載した結晶方位解析法の詳細は、神戸製鋼技報/Vol. 52 No.2(Sep. 2002)P66−70などに詳細に記載されている。
This SEM-EBSD method is widely used as a measurement method of crystal orientation texture, and is applied to a field emission scanning electron microscope (for example, JSM-7000F manufactured by JEOL Ltd.) with a backscattered electron diffraction image (EBSD). Pattern: EBSD) A crystal orientation analysis method equipped with a system.
In the SEM-EBSD method, a sample of an Al alloy plate set in the lens barrel of the FE-SEM is irradiated with an electron beam, and the diffraction pattern of the backscattered electrons is measured by an EBSD apparatus (for example, EBSD measurement manufactured by TSL).・ Analysis system: OIM (Orientation Imaging Macrograph) Data & Analysis) scans the sample surface every 1 μm while analyzing the crystal orientation. Thereby, an EBSP (Electron Back Scatter Diffraction Pattern) at each point is obtained and indexed, and the crystal orientation of the electron beam irradiation site is obtained. The crystal orientation distribution function when the obtained crystal orientation measurement data is rotated by 90 ° around the rolling direction axis and further rotated by 90 ° in the normal direction of the rolling surface and the crystal orientation is measured by EBSD in the entire measurement region. Calculate (ODF) and area ratio. Details of the crystal orientation analysis method in which the EBSD system is mounted on these FE-SEMs are described in detail in Kobe Steel Technical Report / Vol. 52 No. 2 (Sep. 2002) P66-70 and the like.
製造方法:
次に、アルミニウム合金板や、その用途である構造部材の製造方法の実施形態について、以下に説明する。
6000系アルミニウム合金板は、鋳塊を均熱処理後に熱間圧延された熱延板か、更に、この熱延板が冷間圧延された冷延板であって、更に溶体化処理などの調質が施される、常法によって製造される。即ち、工程自体は、常法により、鋳造、均質化熱処理、熱間圧延の通常の各製造工程を経て製造され、板厚が2〜10mm程度であるアルミニウム合金熱延板とされる。次いで、冷間圧延されて板厚が2mm以上、3mm以下の冷延板とされる。
Production method:
Next, an embodiment of a manufacturing method of an aluminum alloy plate or a structural member that is an application thereof will be described below.
The 6000 series aluminum alloy plate is a hot-rolled plate that is hot-rolled after soaking the ingot, or a cold-rolled plate that is cold-rolled from the hot-rolled plate, and is further subjected to tempering such as solution treatment. It is manufactured by a conventional method. That is, the process itself is manufactured by a usual method through normal manufacturing processes such as casting, homogenization heat treatment, and hot rolling to obtain an aluminum alloy hot rolled sheet having a thickness of about 2 to 10 mm. Subsequently, it is cold-rolled to obtain a cold-rolled sheet having a thickness of 2 mm or more and 3 mm or less.
したがって、素材板は、双ロール法などの薄板連続鋳造後に冷延して熱延を省略したり、温間圧延を行うような特殊な製造方法または圧延方法を用いて製造しなくてもよい。   Therefore, the material plate may not be manufactured using a special manufacturing method or a rolling method in which hot rolling is omitted by cold rolling after thin plate continuous casting such as a twin roll method, or warm rolling is performed.
(溶解、鋳造冷却速度)
先ず、溶解、鋳造工程では、上記6000系成分組成範囲内に溶解調整されたアルミニウム合金溶湯を、連続鋳造法、半連続鋳造法(DC鋳造法)等の通常の溶解鋳造法を適宜選択して鋳造する。
(Dissolution, casting cooling rate)
First, in the melting and casting process, an ordinary molten casting method such as a continuous casting method and a semi-continuous casting method (DC casting method) is appropriately selected for the molten aluminum alloy adjusted to be dissolved within the above-mentioned 6000 series component composition range. Cast.
(均質化熱処理)
次いで、前記鋳造されたアルミニウム合金鋳塊に、熱間圧延に先立って、均質化熱処理を施す。この均質化熱処理(均熱処理)は、組織の均質化、すなわち、鋳塊組織中の結晶粒内の偏析をなくすことを目的とする。この均熱処理の条件は、冷却速度も含めて、規定する集合組織には影響が無く、通常の1回だけの均熱でも良く、2回均熱あるいは2段均熱としても良い。1回の均熱では、熱延開始温度まで冷却するか、あるいは熱延開始温度か、その近傍で保持して、熱延を開始する。
(Homogenization heat treatment)
Next, the cast aluminum alloy ingot is subjected to a homogenization heat treatment prior to hot rolling. The purpose of this homogenization heat treatment (soaking) is to homogenize the structure, that is, eliminate segregation in crystal grains in the ingot structure. The conditions for this soaking process have no effect on the texture to be defined, including the cooling rate, and may be normal soaking only once, or twice soaking or two-stage soaking. In one soaking, the hot rolling is started by cooling to the hot rolling start temperature or holding at or near the hot rolling start temperature.
2回均熱とは、1回目の均熱後に、一旦室温を含む200℃以下の温度まで冷却し、更に、再加熱し、その温度で一定時間維持した後に、熱延を開始する。これに対して、2段均熱とは、1回目の均熱後に冷却はするものの、200℃以下までは冷却せず、より高温で冷却を停止した上で、その温度で維持した後に、そのままの温度か、より高温に再加熱した上で熱延を開始する。   In the second soaking, after the first soaking, the steel sheet is once cooled to a temperature of 200 ° C. or less including room temperature, reheated, and maintained at that temperature for a certain time, and then hot rolling is started. On the other hand, the two-stage soaking means cooling after the first soaking, but it is not cooled to 200 ° C. or lower, and after stopping the cooling at a higher temperature, the temperature is maintained as it is. The hot rolling is started after reheating to a higher temperature.
1回のみの均熱、あるいは2回均熱における1回目、あるいは2段均熱における1段目の均熱条件は、450℃以上、固相線温度以下の温度範囲で、2時間以上の保持時間の範囲から適宜選択する。均熱温度を450℃以上とすることで、鋳塊の未固溶析出物の固溶を促進し、最終的な構造部材としての強度の増大をもたらす。   The soaking condition for the first soaking in only one time, the first soaking in the second time, or the soaking in the second stage soaking is maintained at 450 ° C. or more and the solidus temperature for 2 hours or more. Select as appropriate from the time range. By setting the soaking temperature to 450 ° C. or higher, the solid solution of the insoluble precipitate in the ingot is promoted, and the strength as the final structural member is increased.
2回均熱では、この1回目の均熱処理後に、2回均熱のために、一旦、室温を含む200℃以下まで冷却する。また、2段均熱では、この1段目の均熱処理後に、一旦、200℃よりも高温の温度まで冷却する。2回目あるいは2段目の均熱条件は、熱延開始温度以上、500℃以下の温度範囲で2時間以上の保持時間の範囲から選択し、1回目の均熱、冷却後の鋳塊を再加熱し、熱延開始温度まで冷却するか、あるいは熱延開始温度まで再加熱してその近傍で保持すれば良い。また、1段目の均熱後の鋳塊を、熱延開始温度まで冷却して、その近傍で保持しても良い。これら、2回目あるいは2段目の均熱温度は、1回目あるいは1段目の均熱温度よりも低温とする方が好ましい。   In the second soaking, after the first soaking, the temperature is once cooled to 200 ° C. or less including room temperature for the second soaking. In the two-stage soaking, after the first stage soaking, the temperature is once cooled to a temperature higher than 200 ° C. The soaking condition for the second or second stage is selected from the range of the holding time of 2 hours or more in the temperature range of the hot rolling start temperature or higher and 500 ° C. or lower. It may be heated and cooled to the hot rolling start temperature, or reheated to the hot rolling start temperature and held in the vicinity thereof. Further, the ingot after soaking at the first stage may be cooled to the hot rolling start temperature and held in the vicinity thereof. The soaking temperature at the second or second stage is preferably lower than the soaking temperature at the first or first stage.
(熱間圧延)
この熱延において、規定する集合組織とするためには、常法とは異なる条件で、熱延開始温度(熱間粗圧延開始温度)、粗圧延の合計圧下率(%)、熱延の終了温度(熱間仕上げ圧延終了温度)を組み合わせて制御する必要がある。
(Hot rolling)
In this hot rolling, in order to obtain a specified texture, the hot rolling start temperature (hot rough rolling start temperature), the total rolling reduction (%) of the rough rolling, and the end of the hot rolling are performed under conditions different from the conventional methods. It is necessary to control the temperature (hot finish rolling end temperature) in combination.
熱間粗圧延開始温度は、好ましくは、350℃〜450℃の範囲から、前記均熱温度よりも低めとなるように選択する。
熱間粗圧延の合計の圧下率は90%以上とすることが好ましい。
熱間仕上げ圧延の終了温度は、好ましくは150〜280℃のできるだけ低温とすることが好ましい。
このように、熱間粗圧延開始温度、熱間仕上げ圧延終了温度、粗圧延の圧下率の条件を組み合わせることで、熱延中の再結晶後の粒成長を抑制し、結晶粒の粗大化を抑制できる。
また、熱延終了時の熱延材の結晶粒組織を微細なファイバー組織とし、板幅方向の組織むら(集合組織分布)をできるだけ微細にすることで、マクロ的なばらつきを抑制し、最終的な構造部材でのCube方位の面積率の局所的なばらつきを抑制できる。
熱延条件がこれらの条件を満たさない場合、熱延終了時の結晶粒組織(集合組織)がマクロ的にばらつき、耐圧壊性が低下する可能性が高い。
The hot rough rolling start temperature is preferably selected from a range of 350 ° C. to 450 ° C. so as to be lower than the soaking temperature.
The total rolling reduction of the hot rough rolling is preferably 90% or more.
The finishing temperature of hot finish rolling is preferably as low as possible, preferably 150 to 280 ° C.
In this way, by combining the conditions of hot rough rolling start temperature, hot finish rolling end temperature, rough rolling reduction ratio, grain growth after recrystallization during hot rolling is suppressed, and grain coarsening is achieved. Can be suppressed.
In addition, by making the crystal grain structure of the hot-rolled material at the end of hot-rolling a fine fiber structure and minimizing the texture unevenness (texture structure distribution) in the plate width direction as much as possible, the macro variation is suppressed and the final Local variation in the area ratio of the Cube orientation in a simple structural member can be suppressed.
When the hot rolling conditions do not satisfy these conditions, the crystal grain structure (aggregate structure) at the end of hot rolling varies macroscopically, and there is a high possibility that the pressure fracture resistance is lowered.
(冷間圧延)
冷間圧延では、上記熱延板を圧延して、構造部材用として2〜5mmの範囲の所望の最終板厚の冷延板 (コイルも含む) に製作する。この冷延工程の回数は、熱延板の板厚と冷延板の最終板厚との関係で自由に選択され、この1回当たりの冷延工程における冷間圧延機への板(コイル)のパス回数も自由に選択される。
ちなみに、熱延板の冷間圧延前の焼鈍(荒鈍)および冷間圧延途中の中間焼鈍は、施さなくても良いが、必要に応じて施しても良い。
(Cold rolling)
In cold rolling, the hot-rolled sheet is rolled to produce a cold-rolled sheet (including a coil) having a desired final sheet thickness in the range of 2 to 5 mm for a structural member. The number of cold rolling processes is freely selected according to the relationship between the thickness of the hot rolled sheet and the final thickness of the cold rolled sheet, and the sheet (coil) to the cold rolling mill in this cold rolling process. The number of passes can be freely selected.
Incidentally, the annealing (roughening) of the hot-rolled sheet before cold rolling and the intermediate annealing in the middle of cold rolling do not have to be performed, but may be performed as necessary.
(溶体化処理)
冷間圧延後は板の調質としてT4に相当する溶体化および焼入れ処理を行う。この溶体化処理については、通常の連続熱処理ラインによる加熱、冷却でよいが、各元素の十分な固溶量を得ることおよび結晶粒の微細化のためには、500℃以上、固相線温度以下の温度で、保持時間は1秒〜30分の範囲で溶体化処理することが望ましい。
ここで、20℃から、500℃〜固相線温度の溶体化温度域までの、溶体化処理時の平均昇温速度は100〜400℃/分の範囲とすることが好ましい。この平均昇温速度を上記範囲とすることで、板や構造部材の表面や1/4t部のCube方位の発達を促進する。
この平均昇温速度が、この範囲から外れて、速すぎても、板や最終的な構造部材での所望のCube方位の面積率が得られず、Cube方位の局所的なばらつきを抑制できない可能性が生じる。また、この平均昇温速度が、この範囲から外れて遅すぎると、生産性が極端に低下するため、工業的に難しい。
(Solution treatment)
After cold rolling, solution treatment and quenching treatment corresponding to T4 are performed as the tempering of the plate. For this solution treatment, heating and cooling by a normal continuous heat treatment line may be used. However, in order to obtain a sufficient amount of solid solution of each element and refinement of crystal grains, a solidus temperature of 500 ° C. or higher is required. It is desirable to perform the solution treatment at the following temperature at a holding time in the range of 1 second to 30 minutes.
Here, it is preferable that the average temperature increase rate during the solution treatment from 20 ° C. to the solution temperature range of 500 ° C. to the solidus temperature is in the range of 100 to 400 ° C./min. By making this average temperature rising rate within the above range, the surface of the plate or the structural member or the development of the Cube orientation of the 1/4 t portion is promoted.
If this average temperature rise rate is out of this range and is too fast, the area ratio of the desired Cube orientation on the plate or the final structural member cannot be obtained, and local variations in the Cube orientation cannot be suppressed. Sex occurs. In addition, if this average temperature rise rate is out of this range and is too slow, the productivity is extremely reduced, which is industrially difficult.
溶体化処理後の平均冷却(降温)速度は、粗大な化合物の粒界への形成を防止するために、200℃〜固相線温度の範囲を40℃/秒以上とすることが好ましい。このため、溶体化処理後の冷却は、ファンなどの空冷、ミスト、スプレー、浸漬等の水冷手段など、強制的な冷却手段を各々選択して用いるか、室温〜100℃の水や湯に直接焼き入れることが好ましい。   The average cooling (cooling) rate after the solution treatment is preferably set to a range of 200 ° C. to solidus temperature of 40 ° C./second or more in order to prevent formation of coarse compounds at grain boundaries. For this reason, the cooling after the solution treatment is performed by selecting and using forced cooling means such as air cooling such as a fan, water cooling means such as mist, spraying, and immersion, or directly in water or hot water at room temperature to 100 ° C. It is preferable to quench.
(予備時効処理:再加熱処理)
このような溶体化処理後に焼入れ処理して室温まで冷却した後、必要により、冷延板を予備時効処理(再加熱処理)しても良い。
(Preliminary aging treatment: reheating treatment)
After such solution treatment, quenching treatment and cooling to room temperature, the cold-rolled plate may be subjected to preliminary aging treatment (reheating treatment) if necessary.
以上の工程によって、板表面の5mm×5mmの矩形領域におけるCube方位の平均面積率が20%以上であるとともに、板の板厚の1/4厚さ位置における前記板表面と平行な面の5mm×5mmの矩形領域におけるCube方位の平均面積率が25%以上で、かつ、前記板表面のCube方位の平均面積率よりも、前記板の板厚の1/4厚さ位置におけるCube方位の平均面積率の方が大きい素材板を得る。
但し、これら素材板のCube方位を発達させる制御は、従来の溶体化処理までの素材板などの製造工程でのCube方位を発達させる制御を踏襲している。
Through the above steps, the average area ratio of the Cube orientation in a rectangular area of 5 mm × 5 mm on the plate surface is 20% or more, and 5 mm of the plane parallel to the plate surface at the 1/4 thickness position of the plate thickness. The average area ratio of the Cube orientation in a rectangular area of 5 mm is 25% or more, and the average of the Cube orientation at the 1/4 thickness position of the plate thickness of the plate than the average area ratio of the Cube orientation on the plate surface A material plate with a larger area ratio is obtained.
However, the control for developing the Cube orientation of these material plates follows the control for developing the Cube orientation in the manufacturing process of the material plates up to the conventional solution treatment.
このため、素材板の段階で、本発明の実施形態に係る構造部材としての規定を満たす、Cube方位が発達した集合組織を得ることは簡単なことではなく、前記した好ましい製造条件を満たしたとしても、必ず、前記規定を満たす、Cube方位が発達した集合組織が得られるとは限らない。
このため、素材板の集合組織を、本発明で規定する通り、できるだけCube方位が発達した集合組織としておいた上で、後述する構造部材の製造において、素材の構造部材への成形加工で加えるひずみ量、塗装焼付け処理後の人工時効処理の温度、または保持時間の条件を調整して、Cube方位を更に発達させることが好ましい。
また、これが、素材板の集合組織が、構造部材の高強度化と耐圧壊性の向上が図れるほどには、Cube方位が十分発達していなかったとしても、このような素材板を用いて、高強度化と耐圧壊性の向上が図れるCube方位が十分発達した集合組織の構造部材とすることが可能となる、本発明の利点でもある。
For this reason, it is not easy to obtain a texture in which the Cube orientation is developed, which satisfies the provisions as the structural member according to the embodiment of the present invention at the stage of the material plate. However, it is not always possible to obtain a texture in which the Cube orientation has been developed that satisfies the above-mentioned definition.
For this reason, as defined in the present invention, the texture of the material plate is set as a texture where the Cube orientation has been developed as much as possible, and in the production of the structural member described later, the strain applied by forming the material into the structural member It is preferable to further develop the Cube orientation by adjusting the amount, the temperature of the artificial aging treatment after the paint baking treatment, or the holding time.
In addition, even if the Cube orientation is not sufficiently developed so that the texture of the material plate can increase the strength of the structural member and improve the puncture resistance, using such a material plate, It is also an advantage of the present invention that it is possible to obtain a structural member having a texture in which the Cube orientation is sufficiently developed so as to increase the strength and improve the pressure resistance.
構造部材の製法:
前記調質後のアルミニウム合金板は、素材として、バーリング加工、穴拡げ加工などを含む、プレス成形や加工が施されて、特に自動車、あるいは自転車、鉄道車両などの構造部材とされる。更に必要により、電着塗装などの表面処理や塗装処理と、塗装焼付け処理などの人工時効処理(ベークハード、BH)、または塗装せずに、人工時効処理(ベークハード、BH)を施される。
この人工時効処理は、部材に成形する前の、アルミニウム合金板の段階で行うことも可能である。
また、成形性の確保の点で、これら構造部材に成形および加工された後で、別途、必要に応じて、前記人工時効硬化処理されて高強度化されても良い。
Manufacturing method of structural members:
The tempered aluminum alloy plate is subjected to press molding and processing including burring processing, hole expansion processing, and the like as a raw material, and is used as a structural member such as an automobile, a bicycle, or a railway vehicle. Furthermore, if necessary, surface treatment such as electrodeposition and coating treatment, and artificial aging treatment (bake hard, BH) such as paint baking treatment, or artificial aging treatment (bake hard, BH) without painting are performed. .
This artificial aging treatment can also be performed at the stage of the aluminum alloy plate before being formed into a member.
In addition, from the viewpoint of securing moldability, after being molded and processed into these structural members, the artificial age hardening treatment may be performed separately to increase the strength as necessary.
ここで、前記した通り、前記集合組織を有する素材板に予ひずみを与える冷間加工をした上で人工時効処理し、構造部材の表面のCube方位の平均面積率を25%以上とするとともに、1/4t部のCube方位の平均面積率が30%以上とし、かつ、前記表面のCube方位の平均面積率よりも、前記1/4t部のCube方位の平均面積率の方を大きくすることが重要となる。   Here, as described above, artificial aging treatment was performed after pre-straining the material plate having the texture, and the average area ratio of the Cube orientation of the surface of the structural member was 25% or more, The average area ratio of the Cube orientation of the 1 / 4t portion is 30% or more, and the average area ratio of the Cube orientation of the 1 / 4t portion is larger than the average area ratio of the Cube orientation of the surface. It becomes important.
このため、溶体化処理などの調質後のひずみが無い素材板に対して、プレス成形にて、あるいはプレス成形の前後に引張、冷間圧延、レベラー、ストレッチなどの冷間加工を更に加えて、成形された構造部材に、更に、新たに5〜15%の範囲のひずみを付加した上で、更に特定条件下で人工時効処理して、Cube方位の面積率の更なる増大が可能となる。   For this reason, cold working such as tension, cold rolling, leveler, stretch, etc. is further added to the material plate without any strain after tempering such as solution treatment in press molding or before and after press molding. Further, after adding a strain in the range of 5 to 15% to the molded structural member, artificial aging treatment is further performed under a specific condition, so that the area ratio of the Cube orientation can be further increased. .
ただし、これらのひずみを付加する場合には、前記調質後(製造後)のアルミニウム合金板を、前記調質後に、最低でも6時間以上室温時効させてから、前記プレス成形や冷間加工によって、5〜15%の範囲のひずみを付加することが好ましい。
これらの予ひずみは、Cube方位の面積率の更なる増大効果を十分発揮させるためには、構造材においても、素材板の圧延方向に加えることが好ましい。
溶体化処理後の上記室温時効時間経過後に、前記範囲で予ひずみを加えることで、予ひずみの効果が最大化する。上記室温時効時間および予ひずみ量が少なければ、蓄積ひずみ差がつかず、Cube方位粒の粒界移動も少なくなって、Cube方位粒の粒成長や粗大化による、Cube方位の面積率の更なる増大効果が十分発揮されない。
However, when these strains are applied, after the tempering (after manufacture), the aluminum alloy plate is aged at room temperature for at least 6 hours after the tempering, and then by the press molding or cold working. It is preferable to add a strain in the range of 5 to 15%.
These pre-strains are preferably added in the rolling direction of the material plate even in the structural material in order to sufficiently exhibit the effect of further increasing the area ratio of the Cube orientation.
By applying the pre-strain within the above range after the room temperature aging time after the solution treatment, the effect of the pre-strain is maximized. If the room temperature aging time and the amount of pre-strain are small, the accumulated strain difference cannot be obtained, the grain boundary movement of the Cube-oriented grains is also reduced, and the area ratio of the Cube-oriented is further increased by the grain growth and coarsening of the Cube-oriented grains. The increase effect is not sufficiently exhibited.
また、人工時効処理条件は、前記した予ひずみ量との関係で、170〜230℃×5〜30分の範囲とすることが好ましい。この温度範囲や保持間の範囲から外れた場合には、前記特定の範囲の予ひずみとの組み合わせで、Cube方位の面積率の更なる増大ができない可能性が生じる。   In addition, the artificial aging treatment condition is preferably set in a range of 170 to 230 ° C. × 5 to 30 minutes in relation to the above-described prestrain amount. When deviating from the temperature range or the range between holding, there is a possibility that the area ratio of the Cube orientation cannot be further increased in combination with the pre-strain of the specific range.
更に、構造部材のCube方位の平均面積率を、素材の段階のCube方位の平均面積率よりも増大させるためには、前提として、素材板の段階で予め、前記した、表面のCube方位の平均面積率を20%以上とするとともに、1/4t部のCube方位の平均面積率を25%以上とし、かつ、表面のCube方位の平均面積率よりも、1/4t部のCube方位の平均面積率の方を大きくしておく必要がある。つまり、ある程度以上の量のCube方位粒が予ひずみ付加前に存在していないと、予ひずみ+人工時効処理による前記Cube方位の増加効果が現れない。   Furthermore, in order to increase the average area ratio of the Cube orientation of the structural member more than the average area ratio of the Cube orientation at the material stage, as a precondition, the average of the above-described surface Cube orientation at the stage of the material plate is assumed. The area ratio is set to 20% or more, the average area ratio of the 1 / 4t part Cube orientation is set to 25% or more, and the average area ratio of the 1 / 4t part Cube orientation to the average area ratio of the surface Cube orientation. It is necessary to increase the rate. That is, if the amount of Cube orientation grains of a certain amount or more does not exist before the prestrain is added, the effect of increasing the Cube orientation by the prestrain + artificial aging treatment does not appear.
次に、本発明の実施例を説明する。表1に示す組成のアルミニウム合金板を、表2に示す各条件にて、均質化熱処理、熱間圧延、冷間圧延を行い、調質して素材板を製造した。
これら素材板を、構造部材を模擬して、表2に示す各条件にて、予ひずみを付加した上で人工時効処理し、各例のCube方位の発達状態を作り分け、BH後の0.2%耐力およびVDA曲げ試験による耐圧壊性を測定、評価した。これらの結果を表3に各々示す。
なお、表1中の各元素の含有量の表示において、数値を空白としている元素は、その含有量が検出限界以下であることを示す。
また表1〜3において、下線を付した数値等は、本発明の実施形態の範囲から外れていることを意味する。
Next, examples of the present invention will be described. The aluminum alloy plate having the composition shown in Table 1 was subjected to homogenization heat treatment, hot rolling, and cold rolling under the conditions shown in Table 2, and tempered to produce a material plate.
These material plates were simulated for structural members and pre-strained under the conditions shown in Table 2 and then subjected to artificial aging treatment. The 2% proof stress and the fracture resistance by the VDA bending test were measured and evaluated. These results are shown in Table 3, respectively.
In addition, in the display of the content of each element in Table 1, an element whose numerical value is blank indicates that the content is below the detection limit.
Moreover, in Tables 1-3, the numerical value etc. which attached the underline means having removed from the range of embodiment of this invention.
以下に、アルミニウム合金素材板のより具体的な製造条件を説明する。表1に示す各組成の鋳塊を、DC鋳造法にて溶製した。続いて実施した均質化熱処理は、表2に示す均質化温度(到達温度)にて、各例とも共通して4時間の熱処理を実施した。
均熱パターンが2回均熱の場合は、表2に示す1回目の均熱後に、共通して、一旦室温を含む200℃以下の温度まで冷却し、更に、表2に示す熱延開始温度まで再加熱した。 また、1回均熱の場合は、表2に示す均熱後に、熱延開始温度まで冷却し、その温度で熱延を開始した。
熱延は、表2に示す熱延(粗圧延)開始温度、粗圧延の合計の圧下率、熱延(仕上げ圧延)終了温度、で実施した。そして、各熱延板の最終板厚を2.2〜10mmとした。
Below, the more concrete manufacturing conditions of an aluminum alloy raw material board are demonstrated. Ingots having respective compositions shown in Table 1 were melted by a DC casting method. Subsequent homogenization heat treatment was performed at the homogenization temperature (attainment temperature) shown in Table 2 for 4 hours in common with each example.
When the soaking pattern is twice soaking, after the first soaking shown in Table 2, in common, once cooled to a temperature of 200 ° C. or less including room temperature, the hot rolling start temperature shown in Table 2 Until reheated. Moreover, in the case of one-time soaking, after soaking shown in Table 2, it was cooled to the hot rolling start temperature, and hot rolling was started at that temperature.
Hot rolling was carried out at the hot rolling (rough rolling) start temperature shown in Table 2, the total rolling reduction of the rough rolling, and the hot rolling (finish rolling) end temperature. And the final board thickness of each hot-rolled board was made into 2.2-10 mm.
この熱間圧延後の熱延板に対し、冷間圧延を行って共通して2mmの板厚の冷延板を得た。
この冷延板に、表2に示す平均昇温速度(℃/分)、保持温度(溶体化温度)の条件で、溶体化処理を行い、200℃〜固相線温度の範囲を40℃/秒以上の冷却速度で、室温まで冷却し、その後100℃×8時間の予備時効処理を施し、調質T4の素材板を得た。
The hot-rolled sheet after hot rolling was cold-rolled to obtain a cold-rolled sheet having a thickness of 2 mm in common.
This cold-rolled sheet is subjected to a solution treatment under the conditions of the average rate of temperature increase (° C./min) and the holding temperature (solution temperature) shown in Table 2, and the range from 200 ° C. to the solidus temperature is 40 ° C. / The plate was cooled to room temperature at a cooling rate of at least 2 seconds, and then subjected to a pre-aging treatment at 100 ° C. for 8 hours to obtain a tempered T4 blank.
この調質T4の素材板を、各例とも共通して前記調質後に表2に示す各時間(時間)だけ室温時効させてから、構造部材を模擬して、引張試験機により、表2に示す各条件で、板の圧延方向に予ひずみ(引張)を付与した後、表2に示す各条件で、人工時効処理を施した。   The material plate of this tempered T4 is aged in room temperature for each time (time) shown in Table 2 after the tempering in common with each example, and after simulating the structural members, Under each condition shown, after prestraining (tensile) was applied in the rolling direction of the plate, artificial aging treatment was performed under each condition shown in Table 2.
ここで、発明例の場合は、この予ひずみのCube方位の面積率の増大効果を確認するために、引張試験機による予ひずみを付与せずに、表2に示す各条件で、人工時効処理だけを、予ひずみの付与までの室温時効時間と同じ時間だけ経過後に施した例を、参考例として実施した。表2、3における発明例1、3、5、7、9、11がこの参考例に該当する。   Here, in the case of the invention example, in order to confirm the effect of increasing the area ratio of the Cube orientation of this pre-strain, the artificial aging treatment was performed under each condition shown in Table 2 without applying the pre-strain by the tensile tester. The example which performed only after the same time as room temperature aging time until provision of pre-strain passed was implemented as a reference example. Invention examples 1, 3, 5, 7, 9, and 11 in Tables 2 and 3 correspond to this reference example.
(機械的性質)
人工時効処理した板の引張試験は、引張方向が圧延方向と垂直となるようにJIS5号試験片に加工し、評点間距離50mmで引張速度5mm/分で、試験片が破断するまで一定の速度で行った。0.2%耐力(MPa)を測定した。機械的性質の測定に供する引張試験片は、前記供試板から引張方向が圧延方向に平行方向および直角方向となるように、JIS2201の13A号試験片(20mm×80mmGL×板厚1mm)とした。なお、これら引張試験の測定数は2回とし、0.2%耐力はその平均値で求めた。これらの結果を表3に記載する。
(mechanical nature)
The tensile test of the artificially aged plate was processed into a JIS No. 5 test piece so that the tensile direction was perpendicular to the rolling direction, and a constant speed until the test piece broke at a tensile rate of 5 mm / min with a distance between ratings of 50 mm. I went there. 0.2% yield strength (MPa) was measured. The tensile test piece used for measuring the mechanical properties was a JIS2201 No. 13A test piece (20 mm × 80 mmGL × plate thickness 1 mm) so that the tensile direction from the test plate was parallel to and perpendicular to the rolling direction. . In addition, the number of measurements of these tensile tests was set to 2 times, and 0.2% yield strength was calculated | required by the average value. These results are listed in Table 3.
(集合組織)
SEM−EBSD法により測定された集合組織として、前記調質T4の素材板と、構造部材を模擬した前記人工時効処理した板の、表面の5mm×5mmの矩形領域におけるCube方位の平均面積率(%)、厚みの1/4厚さ位置における板表面と平行な面の5mm×5mmの矩形領域におけるCube方位の平均面積率(%)、前記矩形領域を1000μm×1000μmの矩形領域毎に更に各々区切った際の、これら区切られた全ての箇所における、板表面のCube方位の面積率の最小値(%)、板の厚みの1/4厚さ位置におけるCube方位の面積率の最小値(%)を各々、前記した測定方法にて測定した。
測定条件は、視野面積800μm×800μm、結晶方位測定点間の距離(ステップサイズ)3μmとして、測定後に、前記TSL社製OIMのバージョン5を方位解析ソフトウェアとして用いて結晶方位解析を実施した。これらの結果を表3に記載する。
(Gathering organization)
As the texture measured by the SEM-EBSD method, the average area ratio of the Cube orientation in the 5 mm × 5 mm rectangular region of the surface of the tempered T4 material plate and the artificially aged plate simulating a structural member ( %), An average area ratio (%) of Cube orientation in a rectangular area of 5 mm × 5 mm of a plane parallel to the plate surface at a thickness position of ¼ thickness, and the rectangular area is further divided for each rectangular area of 1000 μm × 1000 μm. The minimum value (%) of the area ratio of the Cube orientation on the surface of the plate at all of the divided locations when divided, and the minimum value (%) of the area ratio of the Cube orientation at the 1/4 thickness position of the thickness of the plate ) Were measured by the measurement methods described above.
The measurement conditions were a visual field area of 800 μm × 800 μm and a distance (step size) between crystal orientation measurement points of 3 μm. After measurement, crystal orientation analysis was performed using OSL version 5 manufactured by TSL as orientation analysis software. These results are listed in Table 3.
衝撃吸収性を評価する曲げ試験は、VDA曲げ試験として、前記ドイツ自動車工業会(VDA)の規格の中の「VDA238−100 Plate bending test for metallic materials」に従って実施した。
試験方法は、構造部材を模擬した前記人工時効処理後の板から採取した板状試験片を、その圧延方向と、上方に垂直に立てて配置した板状の押し曲げ治具の延在方向とが、互いに平行になるように、ロールギャップ中央にその中央部が位置するよう、互いに平行に並ぶ2個のロール上に、水平で左右均等の長さに載置する。
そして、上方から前記押し曲げ治具を板状試験片の中央部に押し当てて荷重を負荷し、この板状試験片を前記狭いロールギャップに向けて押し曲げ(突き曲げ)て、曲げ変形した板状試験片中央部を前記狭いロールギャップ内に押し込む。この際に、上方からの押し曲げ治具からの荷重Fが最大となる時の、板状試験片の中央部の曲げ外側の角度を曲げ角度(°)として測定して、その曲げ角度の大きさで衝撃吸収性を評価する。
この曲げ角度が大きいほど、板状試験片は、途中で圧壊せずに、曲げ変形が持続しており、衝撃吸収性(圧壊特性)が高い。これらの結果を表3に記載する。
ここで、前記板状試験片は幅:60mm×長さ:60mmの正方形形状とし、2個のロール直径Dは各々30mm、ロールギャップは板状試験片板厚の2.0倍の4mmとした。また、板状の押し曲げ治具は、板状試験片の中央部に押し当たる下端側の辺が、その先端(下端)の半径が0.2mmφとなるように尖ったテーパ状とした。
The bending test for evaluating the impact absorbability was carried out as a VDA bending test in accordance with “VDA238-100 Plate Bending Test for Metallic Materials” in the standards of the German Automobile Manufacturers Association (VDA).
The test method consists of a plate-like test piece collected from the plate after artificial aging treatment simulating a structural member, its rolling direction, and the extending direction of a plate-like pushing and bending jig arranged vertically upright. However, they are placed horizontally on the two rolls arranged in parallel with each other so that the central portion thereof is positioned in the center of the roll gap so as to be parallel to each other.
Then, the pressing and bending jig is pressed against the center of the plate-shaped test piece from above to apply a load, and the plate-shaped test piece is bent toward the narrow roll gap (bending) to bend and deform. The center part of the plate-shaped test piece is pushed into the narrow roll gap. At this time, when the load F from the push bending jig from above is maximized, the angle of the outer side of the center of the plate-shaped test piece is measured as the bending angle (°), and the bending angle is large. Now evaluate the shock absorption.
The larger the bending angle, the more the plate-like test piece is not crushed in the middle, the bending deformation is continued, and the shock absorption (crushing property) is higher. These results are listed in Table 3.
Here, the plate-shaped test piece has a square shape of width: 60 mm × length: 60 mm, the two roll diameters D are each 30 mm, and the roll gap is 4 mm, which is 2.0 times the plate-shaped test piece plate thickness. . In addition, the plate-like pushing / bending jig had a tapered shape in which the lower end side pressed against the central portion of the plate-like test piece was pointed so that the radius of the tip (lower end) was 0.2 mmφ.
表1〜3に示すように、各発明例の(前記調質T4の)素材板は、本発明成分組成範囲内で、かつ、各製造条件が好ましい範囲で製造されている。
このため、表3に示す通り、各発明例の素材板は、本発明で規定する人工時効処理前の集合組織を有し、表面のCube方位の平均面積率が20%以上であるとともに、1/4t部のCube方位の平均面積率が25%以上で、かつ、表面のCube方位の平均面積率よりも、前記1/4t部のCube方位の平均面積率の方が大きい。
この結果、発明例は、総じて素材板を用途である構造材を模擬して人工時効処理した際の、0.2%耐力が220MPa以上であるとともに、VDA曲げ試験でも80°以上の曲げ角度となる圧壊特性を有して、強度と耐圧壊性とを兼備できている。
As shown in Tables 1 to 3, the material plate (of the tempered T4) of each invention example is manufactured within the composition range of the present invention and within the preferable range of each manufacturing condition.
For this reason, as shown in Table 3, the material plate of each invention example has a texture before the artificial aging treatment defined in the present invention, the average area ratio of the Cube orientation of the surface is 20% or more, and 1 The average area ratio of the Cube orientation of the / 4t portion is 25% or more, and the average area ratio of the Cube orientation of the 1/4 t portion is larger than the average area ratio of the Cube orientation of the surface.
As a result, the invention example generally has a 0.2% proof stress of 220 MPa or more when artificial aging treatment is performed by simulating a structural material used as a material, and a bending angle of 80 ° or more in the VDA bending test. It has the crushing characteristics, and has both strength and crushing resistance.
また、表3の発明例3、4と、5、6と、9、10と、11、12とは、前記矩形領域を1000μm×1000μmの矩形領域毎に各々区切った際の、これら区切られた全ての箇所における、板表面のCube方位の面積率の最小値が15%以上であるとともに、板の厚みの1/4厚さ位置におけるCube方位の面積率の最小値が20%以上である。
このため、板表面のCube方位の面積率の最小値が15%未満か、板の厚みの1/4厚さ位置におけるCube方位の面積率の最小値が20%未満かの、発明例1、2、7、8に比して、人工時効処理した際の、0.2%耐力やVDA曲げ試験での圧壊特性が比較的優れている。
Inventive examples 3, 4, 5, 6, 9, 10, 11, and 12 in Table 3 are divided when the rectangular area is divided into rectangular areas of 1000 μm × 1000 μm. The minimum value of the area ratio of the Cube orientation on the surface of the plate at all locations is 15% or more, and the minimum value of the area ratio of the Cube orientation at the 1/4 thickness position of the thickness of the plate is 20% or more.
For this reason, Invention Example 1 in which the minimum value of the area ratio of the Cube orientation on the plate surface is less than 15% or the minimum value of the area ratio of the Cube orientation in the 1/4 thickness position of the thickness of the plate is less than 20%. Compared to 2, 7, and 8, the 0.2% proof stress and the crushing property in the VDA bending test are relatively excellent when the artificial aging treatment is performed.
更に、構造部材を模擬し、これら素材板を、好ましい範囲で予ひずみを付与した後に人工時効処理を施した表2、3の発明例2、4、6、8、10、12は、表面のCube方位の平均面積率が25%以上であるとともに、1/4t部のCube方位の平均面積率が30%以上で、かつ、表面のCube方位の平均面積率よりも、前記1/4t部のCube方位の平均面積率の方が大きい。
また、これら発明例のうち、表2、3の発明例4、6、8、10、12は、前記矩形領域を1000μm×1000μmの矩形領域毎に各々区切った際の、これら区切られた全ての箇所における、板表面のCube方位の面積率の最小値が25%以上であるとともに、板の厚みの1/4厚さ位置におけるCube方位の面積率の最小値が25%以上である。
Furthermore, the invention members 2, 4, 6, 8, 10, 12 in Tables 2 and 3 in which the structural members were simulated and these material plates were subjected to artificial aging treatment after pre-straining in a preferable range The average area ratio of the Cube orientation is 25% or more, the average area ratio of the Cube orientation of the 1 / 4t part is 30% or more, and the average area ratio of the Cube orientation of the surface is more than that of the 1 / 4t part. The average area ratio of the Cube orientation is larger.
Of these invention examples, Invention Examples 4, 6, 8, 10, and 12 in Tables 2 and 3 are all divided when the rectangular area is divided into rectangular areas of 1000 μm × 1000 μm. The minimum value of the area ratio of the Cube orientation on the surface of the plate at the location is 25% or more, and the minimum value of the area ratio of the Cube orientation at the 1/4 thickness position of the thickness of the plate is 25% or more.
ここで、これらの発明例2、4、6、8、10、12と、予ひずみを施していない表2、3の発明例1、3、5、7、9、11との集合組織を、互いに隣り合う同士、1と2、3と4、5と6、7と8、9と10、11と12の同士で比較する。
すると、発明例2、4、6、8、10、12の方が、予ひずみを付与した人工時効処理によって、板表面と1/4t部のCube方位の平均面積率および、板表面と1/4t部のCube方位の面積率の最小値が、予ひずみを施していない発明例1、3、5、7、9、11よりも増加しており、0.2%耐力およびVDA曲げ試験での圧壊特性が比較的優れている。
したがって、前記好ましい範囲で予ひずみを付与した後に人工時効処理を施すことの効果として、構造部材の厚み方向でのCube方位がより発達するとともに、構造部材の面方向においても、局所的にCube方位の面積率が低い箇所を無くし、Cube方位の面積率の均一化できる効果が裏付けられる。
Here, the textures of these Invention Examples 2, 4, 6, 8, 10, 12 and Invention Examples 1, 3, 5, 7, 9, and 11 of Tables 2 and 3 that are not pre-strained, Next to each other, 1 and 2, 3 and 4, 5 and 6, 7 and 8, 9 and 10, and 11 and 12 are compared.
Then, Invention Examples 2, 4, 6, 8, 10, and 12 were subjected to an artificial aging treatment with a pre-strain, and the average surface area ratio of the plate surface and the 1/4 t part Cube orientation, and the plate surface and 1 / The minimum value of the area ratio of the Cube orientation of the 4t part is increased from those of Invention Examples 1, 3, 5, 7, 9, and 11 that are not pre-strained, and in 0.2% proof stress and VDA bending test. The crushing property is relatively excellent.
Therefore, as an effect of applying the artificial aging treatment after prestraining in the preferred range, the Cube orientation in the thickness direction of the structural member is further developed, and the Cube orientation is also locally localized in the plane direction of the structural member. This eliminates the area where the area ratio is low and supports the effect of making the area ratio of the Cube orientation uniform.
これに対して、比較例13〜19は、表1〜3に示すように、素材板は、本発明成分組成範囲内であるが、製造条件が好ましい範囲を外れて製造されている。
このため、表3に示す通り、これら比較例の素材板は、前記1/4t部のCube方位の平均面積率の方が表面のCube方位の平均面積率よりも小さくなったり、表面のCube方位の平均面積率が20%未満か、1/4t部のCube方位の平均面積率が25%未満で、本発明で規定する集合組織から外れている。
また、構造部材を模擬し、調質T4の素材板を、予ひずみを付与した後に人工時効処理を施した場合も、前記1/4t部のCube方位の平均面積率の方が表面のCube方位の平均面積率よりも小さくなったり、表面のCube方位の平均面積率が25%未満か、1/4t部のCube方位の平均面積率が30%未満で、本発明で規定する集合組織から外れている。
この結果、素材板を用途である構造材を模擬して人工時効処理した際の、0.2%耐力が220MPa未満か、VDA曲げ試験でも80°未満であり、強度と耐圧壊性とを兼備できていない。
In contrast, in Comparative Examples 13 to 19, as shown in Tables 1 to 3, the material plate is manufactured within the composition range of the present invention, but the manufacturing conditions are out of the preferable range.
For this reason, as shown in Table 3, in the material plates of these comparative examples, the average area ratio of the Cube orientation of the 1/4 t part is smaller than the average area ratio of the Cube orientation of the surface, or the Cube orientation of the surface The average area ratio is less than 20%, or the average area ratio in the Cube orientation of the 1/4 t portion is less than 25%, which is out of the texture defined in the present invention.
In addition, when an artificial aging treatment is performed after pre-straining a material plate of tempered T4 by simulating a structural member, the average area ratio of the Cub azimuth of the ¼ t portion is the Cube azimuth of the surface The average area ratio of the Cube orientation of the surface is less than 25%, or the average area ratio of the Cube orientation of the 1 / 4t part is less than 30%, which is outside the texture defined by the present invention. ing.
As a result, the 0.2% proof stress is less than 220 MPa or less than 80 ° in the VDA bending test when simulating the structural material used for the material plate and artificial aging treatment, and it has both strength and pressure resistance. Not done.
比較例13は、均質化温度が低すぎる。
比較例14は、熱延開始温度(粗圧延)が高すぎる。
また、比較例14、15は、人工時効処理温度が高すぎる。
比較例15、16は、熱延終了温度(仕上げ圧延)が高すぎる。
比較例17は、粗圧延の合計圧下率が低すぎ、予ひずみを付与するまでの経過時間が短すぎる。
比較例18、19は、溶体化処理時の平均昇温速度が速すぎ、溶体化温度が低すぎる。
In Comparative Example 13, the homogenization temperature is too low.
In Comparative Example 14, the hot rolling start temperature (rough rolling) is too high.
In Comparative Examples 14 and 15, the artificial aging treatment temperature is too high.
In Comparative Examples 15 and 16, the hot rolling end temperature (finish rolling) is too high.
In Comparative Example 17, the total rolling reduction of rough rolling is too low, and the elapsed time until pre-strain is applied is too short.
In Comparative Examples 18 and 19, the average temperature increase rate during the solution treatment is too fast, and the solution temperature is too low.
また、比較例20、21は、表1に示すように、合金番号7、8のMg、Siの含有量が少なすぎて、製造条件が好ましい範囲で、素材板は、本発明で規定する集合組織を有しているにもかかわらず、構造材を模擬して人工時効処理した際の、0.2%耐力が220MPa未満であり、強度と耐圧壊性とを兼備できていない。   In Comparative Examples 20 and 21, as shown in Table 1, the Mg and Si contents of Alloy Nos. 7 and 8 are too small, and the production conditions are in a preferable range. In spite of having a structure, the 0.2% proof stress is less than 220 MPa when artificial aging treatment is performed by simulating a structural material, and it does not have both strength and pressure resistance.
以上の結果から、強度と耐圧壊性とを兼備するための、本発明において規定する組成や集合組織の意義、そして、これらを得るための好ましい製造条件の意義が裏付けられる。   From the above results, the significance of the composition and texture defined in the present invention for combining strength and pressure resistance, and the significance of preferred production conditions for obtaining these are supported.
本発明によれば、6000系アルミニウム合金組織的な工夫によって、圧延によって製造される板や、この板を成形素材とした構造部材の、強度と耐圧壊性(衝撃吸収性)を向上させることが可能となる。この結果、自動車などの構造部材として、6000系アルミニウム合金板の適用を拡大できる。   According to the present invention, it is possible to improve the strength and puncture resistance (impact absorbability) of a plate manufactured by rolling and a structural member made of this plate as a molding material by systematic innovation of a 6000 series aluminum alloy. It becomes possible. As a result, the application of a 6000 series aluminum alloy plate can be expanded as a structural member for automobiles and the like.

Claims (5)

  1. Mg:0.3〜1.5質量%、Si:0.3〜1.5質量%を含有し、残部がAlおよび不可避的不純物からなり、板厚が2mm以上、5mm以下であるAl−Mg−Si系アルミニウム合金板であって、
    SEM−EBSD法により測定された集合組織として、板表面の5mm×5mmの矩形領域におけるCube方位の平均面積率が20%以上であるとともに、板厚の1/4厚さ位置における前記板表面と平行な面の5mm×5mmの矩形領域におけるCube方位の平均面積率が25%以上で、かつ、前記板表面のCube方位の平均面積率よりも、前記板厚の1/4厚さ位置におけるCube方位の平均面積率の方が大きいことを特徴とする、構造部材用アルミニウム合金板。
    Al—Mg containing Mg: 0.3 to 1.5 mass%, Si: 0.3 to 1.5 mass%, the balance being made of Al and inevitable impurities, and having a plate thickness of 2 mm or more and 5 mm or less -Si-based aluminum alloy plate,
    As the texture measured by the SEM-EBSD method, the average area ratio of the Cube orientation in a rectangular area of 5 mm × 5 mm on the plate surface is 20% or more, and the plate surface at the 1/4 thickness position of the plate thickness The average area ratio of Cube orientation in a rectangular area of 5 mm × 5 mm on a parallel surface is 25% or more, and the Cube orientation at the 1/4 thickness position of the plate thickness is larger than the average area ratio of Cube orientation on the plate surface. An aluminum alloy plate for a structural member, characterized in that the average area ratio of orientation is greater.
  2. 前記アルミニウム合金板が、前記矩形領域を1000μm×1000μmの矩形領域毎に各々区切った際の、これら区切られた全ての箇所における、表面のCube方位の面積率の最小値が15%以上であるとともに、板厚の1/4厚さ位置における板表面と平行な面のCube方位の面積率の最小値が20%以上である集合組織を有する請求項1に記載の構造部材用アルミニウム合金板。   When the aluminum alloy plate divides the rectangular area into rectangular areas each having a size of 1000 μm × 1000 μm, the minimum value of the area ratio of the surface Cube orientation at each of the divided areas is 15% or more. The aluminum alloy plate for a structural member according to claim 1, having a texture in which the minimum value of the area ratio of the Cube orientation of a plane parallel to the plate surface at a 1/4 thickness position of the plate thickness is 20% or more.
  3. 前更に、Cu:0.001〜0.7質量%、Mn:0.05〜0.5質量%、Zr:0.04〜0.20質量%、Cr:0.04〜0.20質量%、Sc:0.02〜0.1質量%、Ag:0.01〜0.2質量%、Sn:0.001〜0.1質量%の一種または二種以上を含有する、請求項1または2に記載の構造部材用アルミニウム合金板。   In addition, Cu: 0.001 to 0.7 mass%, Mn: 0.05 to 0.5 mass%, Zr: 0.04 to 0.20 mass%, Cr: 0.04 to 0.20 mass% Or Sc: 0.02 to 0.1% by mass, Ag: 0.01 to 0.2% by mass, Sn: 0.001 to 0.1% by mass, or one or two or more thereof. 2. The aluminum alloy plate for structural members according to 2.
  4. 5〜15%の予ひずみを付加されるとともに、170〜230℃×5〜30分の人工時効処理を施された後の集合組織が、板表面の5mm×5mmの矩形領域におけるCube方位の平均面積率が25%以上であるとともに、板厚の1/4厚さ位置における前記板表面と平行な面の5mm×5mmの矩形領域におけるCube方位の平均面積率が30%以上で、かつ、前記板表面のCube方位の平均面積率よりも、前記板の板厚の1/4厚さ位置におけるCube方位の平均面積率の方が大きい集合組織を有し、220MPa以上の0.2%耐力とVDA曲げ試験にて80°以上の曲げ角度となる圧壊特性とを有している請求項1乃至3のいずれか1項に記載の構造部材用アルミニウム合金板。   The texture after adding a pre-strain of 5 to 15% and being subjected to artificial aging treatment at 170 to 230 ° C. × 5 to 30 minutes is the average of the Cube orientation in a rectangular region of 5 mm × 5 mm on the plate surface The area ratio is 25% or more, the average area ratio of the Cube orientation in a rectangular area of 5 mm × 5 mm of the plane parallel to the plate surface at the 1/4 thickness position of the plate thickness is 30% or more, and It has a texture in which the average area ratio of the Cube orientation at the 1/4 thickness position of the plate thickness of the plate surface is larger than the average area ratio of the Cube orientation on the plate surface, and 0.2% proof stress of 220 MPa or more The aluminum alloy plate for a structural member according to any one of claims 1 to 3, wherein the aluminum alloy plate has a crushing characteristic that gives a bending angle of 80 ° or more in a VDA bending test.
  5. 請求項1から4のいずれかのアルミニウム合金板に、5〜15%の予ひずみを付加した上で、プレス成形して構造部材となし、この構造部材を人工時効処理することによって、前記構造部材表面の5mm×5mmの矩形領域におけるCube方位の平均面積率が25%以上であるとともに、前記構造部材の厚みの1/4厚さ位置における前記構造部材表面と平行な面の5mm×5mmの矩形領域におけるCube方位の平均面積率が30%以上で、かつ、前記構造部材表面のCube方位の平均面積率よりも、前記構造部材の厚みの1/4厚さ位置におけるCube方位の平均面積率の方が大きい集合組織とし、前記人工時効処理後の構造部材が220MPa以上の0.2%耐力と、VDA曲げ試験にて80°以上の曲げ角度となる圧壊特性とを有するようにしたことを特徴とするアルミニウム合金構造部材の製造方法。   The aluminum alloy plate according to any one of claims 1 to 4, wherein a pre-strain of 5 to 15% is added to the aluminum alloy plate, press forming to form a structural member, and the structural member is subjected to artificial aging treatment, thereby the structural member An average area ratio of Cube orientation in a rectangular area of 5 mm × 5 mm on the surface is 25% or more, and a 5 mm × 5 mm rectangle parallel to the surface of the structural member at a quarter thickness position of the structural member The average area ratio of the Cube orientation in the region is 30% or more, and the average area ratio of the Cube orientation at the 1/4 thickness position of the thickness of the structural member is larger than the average area ratio of the Cube orientation on the surface of the structural member. A larger texture, the structural member after the artificial aging treatment has a 0.2% proof stress of 220 MPa or more, and a crushing characteristic that gives a bending angle of 80 ° or more in the VDA bending test. A method for producing an aluminum alloy structural member, comprising:
JP2017148116A 2017-07-31 2017-07-31 Aluminum alloy sheet for structural member, and manufacturing method of aluminum alloy structural member Pending JP2019026897A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107794419A (en) * 2017-06-13 2018-03-13 湖南东方钪业股份有限公司 A kind of aluminium alloy polynary intermediate alloy and preparation method thereof
CN109972004A (en) * 2019-04-09 2019-07-05 广西大学 A kind of rare earth Sc Modification on Al-Si-Mg alloy and preparation method thereof
CN111041291A (en) * 2019-12-25 2020-04-21 广东凤铝铝业有限公司 High-strength aluminum alloy material and preparation method thereof
CN112760528A (en) * 2020-12-24 2021-05-07 亚太轻合金(南通)科技有限公司 Aluminum alloy for improving crushing performance of 6008 energy-absorbing box and preparation method thereof

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107794419A (en) * 2017-06-13 2018-03-13 湖南东方钪业股份有限公司 A kind of aluminium alloy polynary intermediate alloy and preparation method thereof
CN109972004A (en) * 2019-04-09 2019-07-05 广西大学 A kind of rare earth Sc Modification on Al-Si-Mg alloy and preparation method thereof
CN111041291A (en) * 2019-12-25 2020-04-21 广东凤铝铝业有限公司 High-strength aluminum alloy material and preparation method thereof
CN111041291B (en) * 2019-12-25 2021-02-19 佛山市三水凤铝铝业有限公司 High-strength aluminum alloy material and preparation method thereof
CN112760528A (en) * 2020-12-24 2021-05-07 亚太轻合金(南通)科技有限公司 Aluminum alloy for improving crushing performance of 6008 energy-absorbing box and preparation method thereof

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