JP2009233708A - Multi-layer steel - Google Patents
Multi-layer steel Download PDFInfo
- Publication number
- JP2009233708A JP2009233708A JP2008083453A JP2008083453A JP2009233708A JP 2009233708 A JP2009233708 A JP 2009233708A JP 2008083453 A JP2008083453 A JP 2008083453A JP 2008083453 A JP2008083453 A JP 2008083453A JP 2009233708 A JP2009233708 A JP 2009233708A
- Authority
- JP
- Japan
- Prior art keywords
- layer
- steel
- strength
- tensile strength
- ductility
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 167
- 239000010959 steel Substances 0.000 title claims abstract description 167
- 239000010410 layer Substances 0.000 claims abstract description 193
- 229910000975 Carbon steel Inorganic materials 0.000 claims abstract description 21
- 239000010962 carbon steel Substances 0.000 claims abstract description 21
- 229910000851 Alloy steel Inorganic materials 0.000 claims abstract description 15
- 239000002344 surface layer Substances 0.000 claims abstract description 7
- 229910000734 martensite Inorganic materials 0.000 claims abstract description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 12
- 239000012535 impurity Substances 0.000 claims description 6
- 229910052742 iron Inorganic materials 0.000 claims description 6
- 238000010030 laminating Methods 0.000 claims description 5
- 229910000859 α-Fe Inorganic materials 0.000 claims description 5
- 239000000463 material Substances 0.000 description 25
- 238000005096 rolling process Methods 0.000 description 21
- 229910045601 alloy Inorganic materials 0.000 description 9
- 239000000956 alloy Substances 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 238000005098 hot rolling Methods 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 229910052804 chromium Inorganic materials 0.000 description 5
- 229910052802 copper Inorganic materials 0.000 description 5
- 239000011572 manganese Substances 0.000 description 5
- 229910052750 molybdenum Inorganic materials 0.000 description 5
- 229910052759 nickel Inorganic materials 0.000 description 5
- 229910052719 titanium Inorganic materials 0.000 description 5
- 229910052720 vanadium Inorganic materials 0.000 description 5
- 238000005097 cold rolling Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 229910000617 Mangalloy Inorganic materials 0.000 description 3
- 229910052748 manganese Inorganic materials 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910052758 niobium Inorganic materials 0.000 description 3
- 239000002436 steel type Substances 0.000 description 3
- 229910001369 Brass Inorganic materials 0.000 description 2
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 2
- 229910000677 High-carbon steel Inorganic materials 0.000 description 2
- 239000010951 brass Substances 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000013585 weight reducing agent Substances 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 229910000861 Mg alloy Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 229910000963 austenitic stainless steel Inorganic materials 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 229910001105 martensitic stainless steel Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
Images
Landscapes
- Metal Rolling (AREA)
- Laminated Bodies (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
Description
本発明は、高強度を有すると同時に高延性を備える強度−延性バランスにすぐれた複層鋼に関するものである。 The present invention relates to a multilayer steel having high strength and at the same time having a high ductility and a good balance between strength and ductility.
近年、自動車用材料には、省エネ化、高性能化、環境対策等の観点から軽量化が求められており、その主たる方策として、比重の小さい非鉄材料の利用による軽量化あるいは自動車用鋼材の高強度化による薄肉軽量化等の研究開発が行われている。
しかし、鋼材の代わりに比重の小さい非鉄材料、例えば、Ａｌ合金やＭｇ合金などの合金、を用いると、鋼材に比して、強度や剛性等の機械的特性が十分でないため、鋼材と同等の機械的特性を得るためには、板厚を大にしなければならず、また、断面形状を複雑にしなければならないため、成形性の低下、異材接合における脆化、腐食などの問題も発生し、期待に応えられるほどに十分な軽量化効果を得ることができなかった。
一方、自動車用鋼材を高強度化することにより薄肉化を図った場合には、鋼を高強度化することに付随して派生する諸特性（延性、靭性、剛性、加工性、脆化特性、耐腐食性、耐環境性等）の低下という問題点を解消することが必要とされるが、特に、高強度化と高延性化は一般的に相反する特性であるため、高強度を有すると同時に高延性を備える所謂強度−延性バランスにすぐれた鋼材が強く求められてきた。
In recent years, automotive materials have been required to be lighter from the viewpoint of energy saving, high performance, environmental measures, etc. The main measures are to reduce the weight by using non-ferrous materials with low specific gravity or to increase the steel materials for automobiles. Research and development has been conducted to reduce the thickness and weight by increasing strength.
However, if a non-ferrous material with a low specific gravity is used instead of steel, for example, an alloy such as an Al alloy or Mg alloy, the mechanical properties such as strength and rigidity are not sufficient compared to steel, so it is equivalent to steel. In order to obtain mechanical properties, the plate thickness must be increased, and the cross-sectional shape must be complicated, resulting in problems such as reduced formability, embrittlement in dissimilar material joining, and corrosion. It was not possible to obtain a light weight effect sufficient to meet expectations.
On the other hand, when thinning is achieved by increasing the strength of steel for automobiles, various properties derived from increasing the strength of steel (ductility, toughness, rigidity, workability, embrittlement characteristics, It is necessary to eliminate the problem of deterioration in corrosion resistance, environmental resistance, etc.), but in particular, increasing strength and increasing ductility are generally contradictory properties, so having high strength At the same time, there has been a strong demand for a steel material having a high ductility and a so-called strength-ductility balance.
そのための一つの方策としては、特性の異なる複数の材料の複層化による材料の強度−延性バランスの改善が試みられている。本発明者らの一部は、鋼と他の材料との複層化材料として、組織、機械的特性の異なる鋼（炭素鋼、合金鋼、ステンレス鋼、高マンガン鋼等）を層状に複数層重ねあわせて圧延し、必要に応じ熱処理することにより、強度および延性をともに向上させた複層鋼を提案している（例えば、特許文献１）。
また、例えば、高炭素鋼と黄銅を、複数層重ねあわせて圧接、圧延して得た複層材料においても、高強度、高延性を示す複層材料が得られること（例えば、非特許文献１）が知られている。
In addition, for example, even in a multilayer material obtained by pressing and rolling a plurality of layers of high carbon steel and brass, a multilayer material exhibiting high strength and high ductility can be obtained (for example, Non-Patent Document 1). )It has been known.
上記特許文献１記載の従来技術（以下、従来技術１という）においては、鋼材の組み合わせ、積層層数、積層プロセスを工夫することにより、高強度・高延性の複層鋼が得られることが示されており、例えば、第１の層としてオーステナイト系ステンレス鋼を、また、第２の層としてマルテンサイト系ステンレス鋼を用い、第１の層と第２の層を合計で１１層積層し、温間圧延および熱処理を行うことにより、強度（引張強さＴＳ）が１２２０ＭＰａ、延性（伸びＥＬ）が２５％の複層鋼が得られることが示され、さらに、第１の層として高マンガン鋼を、また、第２の層として炭素鋼を用い、第１の層と第２の層を合計で１１層積層し、熱間圧延および熱処理を行うことにより、強度（引張強さＴＳ）が１１５０ＭＰａ、延性（延びＥＬ）が３４％の複層鋼が得られることが示されている。
しかし、上記従来技術１においては、第１の層及び第２の層がいずれもステンレス鋼同士の組み合わせからなる複層鋼、あるいは、第２の層が高マンガン鋼からなる複層鋼であって、いわば、特殊鋼材同士の組み合わせで高強度・高延性を達成するものである。これらの特殊鋼材は、製造プロセスの厳密な調整・管理が必要とされ、添加成分元素の価格も高価であることから、製造コストが高いという欠点がある。
In the prior art described in Patent Document 1 (hereinafter referred to as Prior Art 1), it is shown that a multilayer steel having high strength and high ductility can be obtained by devising a combination of steel materials, the number of laminated layers, and a lamination process. For example, austenitic stainless steel is used as the first layer, martensitic stainless steel is used as the second layer, and a total of 11 layers of the first layer and the second layer are laminated. By performing hot rolling and heat treatment, it is shown that a multi-layer steel having a strength (tensile strength TS) of 1220 MPa and a ductility (elongation EL) of 25% can be obtained. Further, a high manganese steel is used as the first layer. In addition, carbon steel is used as the second layer, and the first layer and the second layer are laminated in total 11 layers, and by performing hot rolling and heat treatment, the strength (tensile strength TS) is 1150 MPa, Ductility (elongation EL) 34% of the multilayered steel is indicated to be obtained.
However, in the above
一方、上記非特許文献１記載の従来技術（以下、従来技術２という）においては、高炭素鋼と黄銅との組み合わせからなる複層材料として、確かに、強度（７００ＭＰａ程度）および延性（６０％）の高い材料が得られているが、自動車用材料として要求される特性を満足するものであるか否かを考えた場合には、延性は十分であったとしても、７００ＭＰａ程度の引張強さでは、強度特性が極めて不十分であるといわざるを得ず、これを自動車用材料として用いることは非常に難しい。また、従来技術２は、鋼材同士の組み合わせからなる複層鋼ではなく、材料コストも高くなる。
したがって、製造プロセスの簡易化を図ると同時に材料コストの低減を図るためにも、より安価かつ一般的な炭素鋼を用いて、高強度とともに高延性を有し、強度−延性バランスにすぐれた複層鋼の開発が強く望まれている。
On the other hand, in the conventional technology described in Non-Patent Document 1 (hereinafter referred to as Conventional Technology 2), as a multi-layer material composed of a combination of high carbon steel and brass, it certainly has strength (about 700 MPa) and ductility (60% ) Is obtained, but when considering whether or not it satisfies the characteristics required for automobile materials, even if the ductility is sufficient, a tensile strength of about 700 MPa Then, it must be said that the strength characteristics are extremely insufficient, and it is very difficult to use this as an automobile material. Moreover, the
Therefore, in order to simplify the manufacturing process and at the same time reduce the material cost, cheaper and more general carbon steel is used, which has high strength and high ductility, and has a good balance between strength and ductility. Development of layer steel is strongly desired.
本発明の複層鋼は、上記の要請に応えるべく開発されたものであって、
「（１） フェライト組織が最大の体積分率を占める引張強さＴＳ１の炭素鋼または低合金鋼からなる第１の層と、マルテンサイト組織が最大の体積分率を占める引張強さＴＳ２が１２００ＭＰａ以上の炭素鋼または低合金鋼からなる第２の層を互いに積層し、さらに、上記第１の層を表層として合計３層以上を積層一体化して構成してなり、第１の層の層厚ｔ１と第２の層の層厚ｔ２の比（ｔ１／ｔ２）が１．２を超え、かつ、第２の層の引張強さＴＳ２と第１の層の引張強さＴＳ１の比（ＴＳ２／ＴＳ１）が１．２以上６以下であり、複層鋼全体としての引張強さが１０５０ＭＰａ以上、引張強さと全伸びの積が２１０００ＭＰａ・％以上であることを特徴とする複層鋼。
（２） 第１の層のそれぞれの層厚ｔ１が０．０４ｍｍ以上であり、第２の層のそれぞれの層厚ｔ２が０．１ｍｍ以下であることを特徴とする前記（１）記載の複層鋼。
（３） 複層鋼の合計層厚が３．０ｍｍ以下であることを特徴とする前記（１）、（２）記載の複層鋼
（４） 第１の層が、質量％で、
Ｃ：０．０００１〜０．２０％、
Ｓｉ：０．０１〜２．０％、
Ｍｎ：０．０１〜２．０％
を含有し、残部鉄及び不可避的不純物からなる炭素鋼であり、
第２の層が、質量％で、
Ｃ：０．０５〜０．４％、
Ｓｉ：０．０５〜３．０％、
Ｍｎ：０．０５〜３．０％
を含有し、残部鉄及び不可避的不純物からなる炭素鋼であることを特徴とする前記（１）〜（３）記載の複層鋼。
（５） 第１の層が、質量％で、
Ｎｂ：０．００１〜０．１％、
Ｔｉ：０．００１〜０．１％、
Ｖ：０．００１〜０．５％、
Ｃｒ：０．００１〜０．０１％、
Ｎｉ：０．００１〜０．０１％、
Ｍｏ：０．０１〜３．０％、
Ｃｕ：０．０１〜１．０％、
の１種又は２種以上をさらに含有する低合金鋼であることを特徴とする前記（４）記載の複層鋼。
（６） 第２の層が、質量％で、
Ｎｂ：０．００１〜０．１％、
Ｔｉ：０．００１〜０．１％、
Ｖ：０．００１〜０．５％、
Ｃｒ：０．００１〜２．０％、
Ｎｉ：０．００１〜２．５％、
Ｍｏ：０．０１〜１．０％、
Ｃｕ：０．０１〜１．０％、
の１種又は２種以上をさらに含有する低合金鋼であることを特徴とする前記（４）、（５）記載の複層鋼。」
を特徴とするものである。
The multi-layer steel of the present invention was developed to meet the above requirements,
“(1) Tensile strength TS 2 in which the ferrite structure occupies the maximum volume fraction, and a tensile strength TS 2 in which the martensite structure occupies the maximum volume fraction. Is formed by laminating a second layer made of carbon steel or low alloy steel of 1200 MPa or more, and further laminating and integrating a total of three or more layers with the first layer as a surface layer. The ratio (t 1 / t 2 ) of the layer thickness t 1 and the layer thickness t 2 of the second layer exceeds 1.2, and the tensile strength TS 2 of the second layer and the tensile strength of the first layer The ratio of TS 1 (TS 2 / TS 1 ) is 1.2 or more and 6 or less, the tensile strength of the multilayer steel as a whole is 1050 MPa or more, and the product of tensile strength and total elongation is 21000 MPa ·% or more. Multi-layer steel characterized by
(2) The above-mentioned (1), wherein each layer thickness t 1 of the first layer is 0.04 mm or more, and each layer thickness t 2 of the second layer is 0.1 mm or less. Multi-layer steel.
(3) The multilayer steel according to (1) and (2) above, wherein the total thickness of the multilayer steel is 3.0 mm or less.
C: 0.0001 to 0.20%,
Si: 0.01 to 2.0%,
Mn: 0.01 to 2.0%
Is a carbon steel composed of the balance iron and inevitable impurities,
The second layer is, by weight,
C: 0.05-0.4%
Si: 0.05-3.0%,
Mn: 0.05 to 3.0%
The multilayer steel according to any one of (1) to (3) above, characterized in that it is a carbon steel comprising the balance iron and inevitable impurities.
(5) The first layer is mass%,
Nb: 0.001 to 0.1%,
Ti: 0.001 to 0.1%,
V: 0.001 to 0.5%,
Cr: 0.001 to 0.01%,
Ni: 0.001 to 0.01%
Mo: 0.01 to 3.0%,
Cu: 0.01 to 1.0%,
The multi-layer steel according to (4) above, which is a low alloy steel further containing one or more of the above.
(6) The second layer is mass%,
Nb: 0.001 to 0.1%,
Ti: 0.001 to 0.1%,
V: 0.001 to 0.5%,
Cr: 0.001 to 2.0%,
Ni: 0.001 to 2.5%,
Mo: 0.01 to 1.0%,
Cu: 0.01 to 1.0%,
The multilayer steel according to (4) and (5) above, which is a low alloy steel further containing one or more of the above. "
It is characterized by.
以下、本発明について詳細に説明する。 Hereinafter, the present invention will be described in detail.
本発明の複層鋼は、第１の層と第２の層がそれぞれ炭素鋼（普通鋼あるいは普通炭素鋼ともいう）または低合金鋼（Ｎｂ，Ｔｉ，Ｖ，Ｃｒ，Ｎｉ，Ｍｏ，Ｃｕの１種又は２種以上の合金元素の含有量の合計が５％以下の合金鋼をいう）からなり、第１の層と第２の層が、合計で３層以上積層一体化された構造として構成されている。
そして、第１の層は、フェライト組織が最大の体積分率を占める炭素鋼または低合金鋼（以下、「α鋼」で示す）からなり、一方、第２の層はマルテンサイト組織が最大の体積分率を占める炭素鋼または低合金鋼（以下、「Ｍａｒ鋼」で示す）からなっている。
さらに、複層鋼全体としての高強度化を図るために、第２の層の構成材料として高い引張強さを有するＭａｒ鋼を用いるばかりでなく、複層鋼の第1の層および表層を構成するα鋼としても、少なくとも所定値以上の引張強さを備えなければならない。ここで、α鋼の引張強さをＴＳ１で示し、Ｍａｒ鋼の引張強さをＴＳ２で示した場合、ＴＳ２は１２００ＭＰａ以上で、かつ、Ｍａｒ鋼の引張強さＴＳ２とα鋼の引張強さＴＳ１の比の値（ＴＳ２／ＴＳ１）が１．２以上でかつ６以下を満足するようなＴＳ１の値でなければならない。
その一方で、本発明の複層鋼は単に強度を向上させるばかりでなく、同時にその延性も高めることが必要であるところ、第１の層および表層を構成するα鋼の層厚をｔ１、また、第２の層を構成するＭａｒ鋼の層厚をｔ２とした場合、第１の層（α鋼）の層厚ｔ１と第２の層（Ｍａｒ鋼）の層厚ｔ２は、
ｔ１／ｔ２＞１．２
の関係を満足していなければならない。
つまり、第１の層（α鋼）の層厚ｔ１が第２の層（Ｍａｒ鋼）の層厚ｔ２の１．２倍を超えない限り、仮に、複層鋼の高強度化が図れたとしても、複層鋼全体としての伸びの値（ＥＬ値）が著しく低下し、引張強さと全伸びの積は２１０００ＭＰａ・％未満にとどまるため、複層鋼にすぐれた強度−延性バランスを具備せしめることができないからである。
上記のとおり、本発明の複層鋼は、第１の層を層厚ｔ１のα鋼で構成し、また、第２の層を層厚ｔ２のＭａｒ鋼で構成し、ｔ１／ｔ２＞１．２となるように第１の層および第２の層の層厚をそれぞれ定め、さらに、α鋼の引張強さをＴＳ１、Ｍａｒ鋼の引張強さをＴＳ２とした場合に、１．２≦ＴＳ２／ＴＳ１≦６となるような鋼種の組み合せ等の調整によって、複層鋼全体としての引張強さが１０５０ＭＰａ以上、引張強さと全伸びの積が２１０００ＭＰａ・％以上である高強度、高延性かつ強度−延性バランスにすぐれた複層鋼を得ることができる。
In the multilayer steel of the present invention, the first layer and the second layer are made of carbon steel (also called ordinary steel or ordinary carbon steel) or low alloy steel (Nb, Ti, V, Cr, Ni, Mo, Cu, respectively). The total content of one or more alloy elements is 5% or less), and the first layer and the second layer are laminated and integrated in a total of three or more layers. It is configured.
The first layer is made of carbon steel or low alloy steel (hereinafter referred to as “α steel”) in which the ferrite structure occupies the maximum volume fraction, while the second layer has the largest martensite structure. It consists of carbon steel or low alloy steel (hereinafter referred to as “Mar steel”) occupying a volume fraction.
Furthermore, in order to increase the strength of the multilayer steel as a whole, not only Mar steel having high tensile strength is used as the constituent material of the second layer, but also the first layer and the surface layer of the multilayer steel are constructed. The α steel to be used must have at least a predetermined tensile strength. Here, the tensile strength of the α steel shown in TS 1, if the tensile strength of the Mar steel shown in TS 2, TS 2 in the above 1200 MPa, and the Mar steel tensile strength TS 2 and the α steel The ratio of the tensile strength TS 1 (TS 2 / TS 1 ) must be a value of TS 1 that satisfies 1.2 or more and 6 or less.
On the other hand, the multi-layer steel of the present invention not only simply improves the strength, but at the same time it is necessary to increase the ductility, the layer thickness of the α steel constituting the first layer and the surface layer is t 1 , in addition, when the thickness of the Mar steel constituting the second layer was t 2, the thickness t 1 of the first layer (alpha steel) thickness t 2 of the second layer (Mar steel) is
t 1 / t 2 > 1.2
Must be satisfied with the relationship.
That is, as long as the layer thickness t1 of the first layer (α steel) does not exceed 1.2 times the layer thickness t2 of the second layer (Mar steel), the strength of the multilayer steel can be increased. Even so, the elongation value (EL value) of the multilayer steel as a whole is significantly reduced, and the product of the tensile strength and the total elongation is less than 21000 MPa ·%, so that the multilayer steel has an excellent strength-ductility balance. This is because they cannot be squeezed.
As described above, the multi-layer steel of the present invention includes a first layer made of α-steel having a layer thickness t 1, and a second layer made of Mar steel having a layer thickness t 2 , wherein t 1 / t When the thicknesses of the first layer and the second layer are determined so that 2 > 1.2, and the tensile strength of α steel is TS 1 and the tensile strength of Mar steel is TS 2 , 1.2 ≦ TS 2 / TS 1 ≦ 6 By adjusting the combination of steel types, etc., the tensile strength of the multilayer steel as a whole is 1050 MPa or more, and the product of tensile strength and total elongation is 21000 MPa ·% or more. It is possible to obtain a multilayer steel having a certain high strength, high ductility and excellent strength-ductility balance.
そして、前記複層鋼は、例えば、以下の製造法によって製造することができる。
まず、相対的に強度ＴＳ２は高いが延性の低いＭａｒ鋼からなる層厚ｔ２の第２の層を、相対的に延性に優れるが強度ＴＳ１の低いα鋼からなる層厚ｔ１の第１の層で挟み、その上に、上記第２の層を積層し、この上に更に上記第１の層を積層し、このような積層工程を順次繰り返し、合計層数Ｎ層（但し、Ｎ≧３）であって、かつ、表層が延性に富む上記第１の層（α鋼）からなる積層体を形成する（なお、ｔ１／ｔ２＞１．２、かつ、１．２≦ＴＳ２／ＴＳ１≦６の条件を満たすことが必要）。
その後、上記積層体に対して熱間圧延、冷間圧延等の圧延を行うことにより、積層体を一体化し複層鋼を得る。圧延温度、圧下率等の圧延条件については、上記積層体を圧延で一体化できる条件であれば良く、特に限定されるものではないが、各層間の密着強度を強固なものにするという点からは、熱間圧延温度は６５０〜１１５０℃、圧下率（圧延前の層の厚さに対する圧延後の層の厚さの減少率）は４０〜６０％とすることが望ましい。
And the said multilayer steel can be manufactured with the following manufacturing methods, for example.
First, relatively strength TS 2 is high but the second layer of the layer thickness t 2 consisting of low Mar steel ductility is excellent relatively ductile layer thickness t 1 consisting of lower α steel strength TS 1 Sandwiched between the first layers, the second layer is stacked thereon, the first layer is further stacked thereon, and the stacking process is sequentially repeated until the total number of layers is N (however, N ≧ 3) and a laminate composed of the first layer (α steel) whose surface layer is rich in ductility is formed (note that t 1 / t 2 > 1.2 and 1.2 ≦ TS 2 / TS 1 ≦ 6 must be satisfied).
Thereafter, the laminated body is integrated by rolling such as hot rolling and cold rolling to obtain the multilayer steel. About rolling conditions, such as rolling temperature and rolling reduction, what is necessary is just the conditions which can integrate the said laminated body by rolling, Although it does not specifically limit, From the point of making the adhesive strength between each layer strong. The hot rolling temperature is preferably 650 to 1150 ° C., and the rolling reduction (the reduction rate of the layer thickness after rolling with respect to the layer thickness before rolling) is preferably 40 to 60%.
本発明の複層鋼の層厚については、高強度、高延性を有するとともに軽量化を図るという観点から、第１の層（α鋼）のそれぞれの層厚ｔ１が０．０４ｍｍ以上であり、第２の層（Ｍａｒ鋼）のそれぞれの層厚ｔ２が０．１ｍｍ以下であることが望ましく、また、複層鋼の合計層厚は３．０ｍｍ以下とすることが望ましい。 As for the layer thickness of the multilayer steel of the present invention, each layer thickness t 1 of the first layer (α steel) is 0.04 mm or more from the viewpoint of high strength, high ductility and weight reduction. , it is desirable each of the thickness t 2 of the second layer (Mar steel) is 0.1mm or less, the total layer thickness of the multilayered steel is preferably set to 3.0mm or less.
本発明の複層鋼の第１の層を構成するα鋼、あるいは、第２の層を構成するＭａｒ鋼については、いずれも製造が容易でかつ安価な炭素鋼（普通鋼あるいは普通炭素鋼ともいう）または低合金鋼を使用する。
第１の層を構成するα鋼としては、引張強さは十分でないが延性にすぐれた鋼を用いることが必要であり、具体的には、Ｃ：０．０００１〜０．１０％、Ｓｉ：０．０１〜２．０％、Ｍｎ：０．０１〜２．０％（いずれも質量%）、残部鉄及び不可避的不純物からなる成分組成を有する炭素鋼であって、その組織の主要相をフェライト組織とすることにより、例えば、引張強さがほぼ４００〜１０００ＭＰａの特性を有する鋼である。後述するように更に合計量が５％以下のＮｂ，Ｔｉ，Ｖ，Ｃｒ，Ｎｉ，Ｍｏ，Ｃｕの１種又は２種以上からなる合金元素を含有してもよい。
一方、第２の層を構成するＭａｒ鋼としては、延性は低くても高引張強さを有する鋼を用いることが必要であり、具体的には、Ｃ：０．１２〜０．４％、Ｓｉ：０．０５〜３．０％、Ｍｎ：０．０５〜３．０％（いずれも質量%）、残部鉄及び不可避的不純物からなる成分組成を有する炭素鋼であって、上記α鋼に比してＣ含有量の高い炭素鋼、あるいは更に、α鋼に比してＳｉ、Ｍｎ成分の含有量を相対的に増加させて、その組織の主要相をマルテンサイト組織とすることにより、引張強さを１２００ＭＰａ以上に調整した鋼である。後述するように更に合計量が５％以下のＮｂ，Ｔｉ，Ｖ，Ｃｒ，Ｎｉ，Ｍｏ，Ｃｕの１種又は２種以上からなる合金元素を含有してもよい。
なお、上記α鋼およびＭａｒ鋼のいずれにおいても、その延性（伸び）は、成分組成、熱処理条件等によって影響されるが、概ね、α鋼については、伸びは２０〜４５％、また、Ｍａｒ鋼については、伸びは３〜１０％のものとなる。
そして、本発明においては、引張強さ（ＴＳ１）は十分でないが延性にすぐれたα鋼と、延性は低くてもすぐれた引張強さ（ＴＳ２）を有するＭａｒ鋼（但し、１．２≦ＴＳ２／ＴＳ１≦６）とを、α鋼の層厚ｔ１とＭａｒ鋼の層厚ｔ２が、ｔ１／ｔ２＞１．２となるように積層し、一体化することにより、α鋼とＭａｒ鋼がそれぞれ有する特性を相兼ね備えたすぐれた特性、すなわち、すぐれた高強度、高延性と強度−延性バランス、の複層鋼を得ることができる。
As for the α steel constituting the first layer of the multi-layer steel of the present invention or the Mar steel constituting the second layer, carbon steel that is easy to manufacture and inexpensive (both ordinary steel and ordinary carbon steel) Or low alloy steel.
As the α steel constituting the first layer, it is necessary to use a steel which is not sufficient in tensile strength but has excellent ductility. Specifically, C: 0.0001 to 0.10%, Si: 0.01 to 2.0%, Mn: 0.01 to 2.0% (both mass%), carbon steel having a composition composed of the balance iron and inevitable impurities, the main phase of the structure By using a ferrite structure, for example, the steel has a tensile strength of approximately 400 to 1000 MPa. As will be described later, a total amount of 5% or less of Nb, Ti, V, Cr, Ni, Mo, and Cu may be included as an alloy element.
On the other hand, as Mar steel constituting the second layer, it is necessary to use steel having high tensile strength even if ductility is low. Specifically, C: 0.12 to 0.4%, Si: 0.05-3.0%, Mn: 0.05-3.0% (both mass%), carbon steel having a composition composed of the balance iron and unavoidable impurities, Carbon steel with a higher C content than that of α steel, and further, by relatively increasing the content of Si and Mn components as compared with α steel, the main phase of the structure is a martensitic structure. Steel whose strength is adjusted to 1200 MPa or more. As will be described later, a total amount of 5% or less of Nb, Ti, V, Cr, Ni, Mo, and Cu may be included as an alloy element.
In both the α steel and the Mar steel, the ductility (elongation) is influenced by the component composition, heat treatment conditions, etc., but the elongation is generally 20 to 45% for the α steel, and the Mar steel. The elongation is between 3 and 10%.
In the present invention, an α steel having an excellent tensile strength (TS 1 ) but excellent ductility, and a Mar steel having an excellent tensile strength (TS 2 ) even if ductility is low (1.2 ≦ TS 2 / TS of 1 ≦ 6) and, by a layer thickness t 2 of the thickness t 1 and Mar steel α steel, laminated so that t 1 /
さらに、本発明の複層鋼の第１の層を構成するα鋼は、合計量が５％以下の合金成分（Ｎｂ：０．００１〜０．１％、Ｔｉ：０．００１〜０．１％、Ｖ：０．００１〜０．５％、Ｃｒ：０．００１〜０．０１％、Ｎｉ：０．００１〜０．０１％、Ｍｏ：０．０１〜３．０％、Ｃｕ：０．０１〜１．０％の１種又は２種以上。いずれも質量％）を更に含有することができる。
これらの合金成分を、それぞれ上記のごとく定められた所定量含有することによって、α鋼それ自体の有する強度、延性、靭性等の機械的特性を調整することができる。ただ、引張強さＴＳ１については、１．２≦ＴＳ２／ＴＳ１≦６を満足させることが必要であり、この値が６を超えたような場合には、例え、延性、靭性にすぐれた複層鋼が得られたとしても、強度−延性バランスを欠く好ましくない複層鋼が形成されることとなるので注意が必要であり、一方、良好な延性を確保するためには、ＴＳ２／ＴＳ１≧１．２とすることが必要である。
Further, the α steel constituting the first layer of the multilayer steel of the present invention has a total amount of alloy components (Nb: 0.001 to 0.1%, Ti: 0.001 to 0.1). %, V: 0.001 to 0.5%, Cr: 0.001 to 0.01%, Ni: 0.001 to 0.01%, Mo: 0.01 to 3.0%, Cu: 0.00. 01-1.0% of 1 type or 2 types or more.
By containing these alloy components in predetermined amounts as defined above, mechanical properties such as strength, ductility and toughness of the α steel itself can be adjusted. However, it is necessary for the tensile strength TS 1 to satisfy 1.2 ≦ TS 2 / TS 1 ≦ 6. If this value exceeds 6, the ductility and toughness are excellent. Even if a multilayer steel is obtained, it is necessary to be careful because an undesirable multilayer steel lacking the strength-ductility balance is formed. On the other hand, in order to ensure good ductility, TS 2 / TS 1 ≧ 1.2 is required.
また、本発明の複層鋼の第２の層を構成するＭａｒ鋼としては、合計量が５%以下の合金成分（Ｎｂ：０．００１〜０．１％、Ｔｉ：０．００１〜０．１％、Ｖ：０．００１〜０．５％、Ｃｒ：０．００１〜２．０％、Ｎｉ：０．００１〜２．５％、Ｍｏ：０．０１〜１．０％、Ｃｕ：０．０１〜１．０％の１種又は２種以上。いずれも質量％）を添加含有することができる。
これらの合金成分を、それぞれ上記のごとく定められた所定量含有することによって、Ｍａｒ鋼の有する強度、延性、靭性等の機械的特性を調整することができるが、多量に添加含有させた場合には、鋼種が合金鋼の範疇となり、製造コストも高くなることから、添加含有する合金成分とその含有量を上記の如く定めた。
Moreover, as Mar steel which comprises the 2nd layer of the multilayer steel of this invention, a total amount is 5% or less of an alloy component (Nb: 0.001-0.1%, Ti: 0.001-0. 1%, V: 0.001 to 0.5%, Cr: 0.001 to 2.0%, Ni: 0.001 to 2.5%, Mo: 0.01 to 1.0%, Cu: 0 0.01% to 1.0% or two or more, both of which are added by mass%).
The mechanical properties such as strength, ductility, and toughness of Mar steel can be adjusted by containing these alloy components in the prescribed amounts determined as described above. Since the steel type falls into the category of alloy steel and the manufacturing cost increases, the alloy components to be added and the content thereof are determined as described above.
本発明の複層鋼は、第１の層を層厚ｔ１のα鋼で構成し、また、第２の層を層厚ｔ２のＭａｒ鋼で構成し、ｔ１／ｔ２＞１．２となるように第１の層および第２の層の層厚をそれぞれ定め、さらに、α鋼の引張強さをＴＳ１、Ｍａｒ鋼の引張強さをＴＳ２とした場合に、１．２≦ＴＳ２／ＴＳ１≦６となるように、鋼種を組み合わせる等によって強度比を調整することにより、第１の層および第２の層がそれぞれ有するすぐれた特性（即ち、第１層の有するすぐれた延性および第２層の有する高強度）を相兼ね備え、かつ、強度−延性バランスにすぐれた複層鋼を得ることができる。そして、複層鋼全体としては、引張強さが１０５０ＭＰａ以上、引張強さと全伸びの積が２１０００ＭＰａ・％以上を示すことから、例えば高強度、高延性が要求され、軽量化が求められる自動車用材料として好適な材料であるといえる。 In the multi-layer steel of the present invention, the first layer is composed of α-steel having a layer thickness t 1 , and the second layer is composed of Mar steel having a layer thickness t 2 , where t 1 / t 2 > 1. When the layer thicknesses of the first layer and the second layer are respectively determined to be 2, and the tensile strength of the α steel is TS 1 and the tensile strength of the Mar steel is TS 2 , By adjusting the strength ratio by combining steel types so that ≦ TS 2 / TS 1 ≦ 6, excellent characteristics that each of the first layer and the second layer have (that is, excellent characteristics of the first layer) In addition, it is possible to obtain a multilayer steel having a good balance between strength and ductility and a high strength of the second layer. And as a whole multi-layer steel, since the tensile strength is 1050 MPa or more and the product of tensile strength and total elongation is 21000 MPa ·% or more, for example, high strength and high ductility are required, and the weight reduction is required. It can be said that the material is suitable as a material.
本発明は、組織および機械的特性の異なるα鋼とＭａｒ鋼とを組み合わせて複層化してなる複層鋼であり、α鋼とＭａｒ鋼の強度の比および層厚の比を適正なものとすることにより、強度−延性バランスにすぐれ、しかも複層鋼全体としての高強度化・高延性化を図ることができる。 The present invention is a multi-layer steel formed by combining α steel and Mar steel having different structures and mechanical properties, and has a proper strength ratio and layer thickness ratio of α steel and Mar steel. By doing so, the strength-ductility balance is excellent, and the strength and ductility of the multilayer steel as a whole can be increased.
本発明者らは、まず、α鋼とＭａｒ鋼の強度の比ＴＳ２／ＴＳ１と、引張強さと全伸びの積ＴＳ×Ｅｌとの関係について検討を行った。その結果、図１に示すように、ＴＳ２／ＴＳ１が６以下になると、ＴＳ×Ｅｌが２１０００ＭＰａ・％以上になることがわかった。これは、Ｍａｒ鋼の強度に対してα鋼の強度が低すぎると、強度−延性バランスが低下することを意味する。
次に、本発明者らは、α鋼とＭａｒ鋼の層厚の比ｔ１／ｔ２と、引張強さと全伸びの積ＴＳ×Ｅｌとの関係について検討を行った。その結果、図２に示すように、ｔ１／ｔ２が１．２を超えると、ＴＳ×Ｅｌが２１０００ＭＰａ・％以上になることがわかった。これは、Ｍａｒ鋼の層厚よりも、α鋼の層厚を大きくすることによって、強度−延性バランスが向上することを意味する。
したがって、Ｍａｒ鋼をα鋼によって拘束し、変形時のＭａｒ鋼のネッキングを回避するためには、各層の強度の差が大き過ぎないこと、軟質のα鋼の層厚を大きくすること、が必要である。
The inventors first examined the relationship between the strength ratio TS 2 / TS 1 of α steel and Mar steel and the product TS × El of tensile strength and total elongation. As a result, as shown in FIG. 1, it was found that when TS 2 / TS 1 was 6 or less, TS × El was 21000 MPa ·% or more. This means that the strength-ductility balance decreases if the strength of the α steel is too low relative to the strength of the Mar steel.
Next, the present inventors examined the relationship between the layer thickness ratio t 1 / t 2 of α steel and Mar steel and the product TS × El of tensile strength and total elongation. As a result, as shown in FIG. 2, it was found that when t 1 / t 2 exceeds 1.2, TS × El is 21000 MPa ·% or more. This means that the strength-ductility balance is improved by increasing the thickness of the α steel compared to the thickness of the Mar steel.
Therefore, in order to constrain Mar steel with α steel and avoid necking of Mar steel at the time of deformation, it is necessary that the difference in strength of each layer is not too large and that the thickness of soft α steel is increased. It is.
本発明の複層鋼は、強度ＴＳ２は高いが延性の低いＭａｒ鋼からなる層厚ｔ２の第２の層を、相対的に延性に優れるが強度ＴＳ１の低いα鋼からなる層厚ｔ１の第１の層で挟み、その上に、上記第２の層を積層し、この上に更に上記第１の層を積層し、このような積層工程を順次繰り返し、合計層数３〜２１層で、かつ、表層を延性に富む上記第１の層（α鋼）からなる積層体とし、その後、これを圧延により一体化することにより形成した複層鋼である。 The multi-layer steel of the present invention has a layer thickness t 2 made of Mar steel having high strength TS 2 but low ductility, and a layer thickness made of α steel having relatively high ductility but low strength TS 1. sandwiched between the first layers of t 1 , the second layer is laminated thereon, the first layer is further laminated thereon, and such a laminating step is sequentially repeated, for a total number of layers of 3 It is a multi-layer steel formed by forming a laminate composed of the above-mentioned first layer (α steel) having 21 layers and having a high ductility, and then integrating these by rolling.
本発明では、積層一体化された複層鋼を製造するために、第１の層と第２の層とからなる積層体を形成した後、例えば、熱間圧延、冷間圧延、温間圧延、熱間圧延及び冷間圧延を併用した圧延、熱間圧延及び温間圧延を併用した圧延等、適宜の圧延方法により積層体を一体化する。特に、熱間圧延を用いた場合には、圧延時に、第１の層と第２の層との層間に拡散が生じ、その結果として、各層間の層間密着強度が向上するようになる。
なお、冷間圧延、温間圧延を行った場合であっても、圧延後に所定の熱処理を施すことにより、前記同様、層間に拡散が生じる結果、各層間の層間密着強度が向上し、複層鋼の強度の向上、延性の向上が図られるが、その際の熱処理温度の下限は６００℃以上であることが望ましい。強度を高めるためには、圧延後、第２の層の組織がオーステナイトになる温度域以上、例えば、８００℃以上に加熱し、水冷することが好ましい。
In the present invention, in order to produce a multi-layer steel that is laminated and integrated, after forming a laminate composed of a first layer and a second layer, for example, hot rolling, cold rolling, warm rolling The laminated body is integrated by an appropriate rolling method such as rolling using both hot rolling and cold rolling, rolling using both hot rolling and warm rolling. In particular, when hot rolling is used, diffusion occurs between the first layer and the second layer during rolling, and as a result, the interlayer adhesion strength between the layers is improved.
Even when cold rolling or warm rolling is performed, by performing a predetermined heat treatment after rolling, as described above, diffusion occurs between the layers. The strength and ductility of the steel can be improved, but the lower limit of the heat treatment temperature is preferably 600 ° C. or higher. In order to increase the strength, it is preferable that after rolling, the second layer is heated to a temperature range or higher, for example, 800 ° C. or higher, where the second layer structure becomes austenite, and then water-cooled.
以下、具体的な実施例により本発明をさらに詳細に説明する。 Hereinafter, the present invention will be described in more detail with reference to specific examples.
本発明では、第１の層として表１に示す３種のα鋼を用い、また、第２の層として同じく表１に示す４種のＭａｒ鋼を用いた。なお、それぞれの鋼の引張強さを同じく表１に示す。 In the present invention, three types of α steel shown in Table 1 were used as the first layer, and four types of Mar steel shown in Table 1 were used as the second layer. Table 1 also shows the tensile strength of each steel.
表１に示す第１の層と第２の層を、表３（表２のつづき）に示す組み合わせ、各層層厚、積層層数、合計層厚となるように積層して積層体を形成し、さらに、これらの積層体を、表２に示す条件で圧延及び／または熱処理し一体化することにより、実施例１〜１２として示す本発明の複層鋼を製造した。 The first layer and the second layer shown in Table 1 are laminated so as to have the combinations shown in Table 3 (continued in Table 2), the thickness of each layer, the number of laminated layers, and the total layer thickness to form a laminate. Furthermore, these laminated bodies were rolled and / or heat-treated under the conditions shown in Table 2 to integrate them, thereby producing multilayer steels of the present invention shown as Examples 1 to 12.
例えば、実施例１では、表１に示す第１の層として、厚さ１．３ｍｍのα鋼、また、第２の層として、厚さ１．０ｍｍのＭａｒ鋼を用い、第１の層を９層、第２の層を８層交互に積層し、表層が第１の層となるようにして、合計積層数１７層、合計層厚１９．７ｍｍの積層体を形成した。
次いで、上記積層体を、表３に示す各層層厚、積層層数、合計層厚となるように、表２に示す条件で熱間圧延し、さらに、同じく表２に示す条件で熱処理することにより、実施例１の複層鋼を作製した。
そして、作製した実施例１の複層鋼の各層の層厚方向中心位置を光学顕微鏡で観察したところ、第１の層は、フェライト組織がほぼ１００体積％を占めるα鋼であり、一方、第２の層はマルテンサイト組織がほぼ１００体積％を占めるＭａｒ鋼であることを確認した。
For example, in Example 1, α steel having a thickness of 1.3 mm is used as the first layer shown in Table 1, and Mar steel having a thickness of 1.0 mm is used as the second layer. Nine layers and eight second layers were alternately laminated so that the surface layer was the first layer, and a laminate having a total number of layers of 17 and a total layer thickness of 19.7 mm was formed.
Next, the laminate is hot-rolled under the conditions shown in Table 2 so as to have each layer thickness, the number of laminated layers, and the total layer thickness shown in Table 3, and further heat-treated under the conditions shown in Table 2. Thus, the multilayer steel of Example 1 was produced.
And when the layer thickness direction center position of each layer of the produced multilayer steel of Example 1 was observed with an optical microscope, the first layer is α steel in which the ferrite structure occupies almost 100% by volume, It was confirmed that the second layer was Mar steel in which the martensite structure accounted for almost 100% by volume.
得られた実施例１〜１２の本発明複層鋼についての、ｔ１／ｔ２の値、ＴＳ２／ＴＳ１の値、さらに、複層鋼全体としての引張強さ（ＭＰａ）、伸び（％）および強度−延性バランス指標値（引張強さ（ＭＰａ）×伸び（％）の値）を、表３に示す。
表３の結果からも明らかなように、実施例１〜１２の本発明複層鋼は、高強度とともに高延性を有し、しかも、強度−延性バランスに優れる複層鋼であることが確認された。
Regarding the obtained multilayer steels of Examples 1 to 12, the value of t 1 / t 2 , the value of TS 2 / TS 1 , and the tensile strength (MPa) and elongation as a whole of the multilayer steel ( %) And strength-ductility balance index values (value of tensile strength (MPa) × elongation (%)) are shown in Table 3.
As is clear from the results in Table 3, it is confirmed that the present invention multilayer steels of Examples 1 to 12 are multilayer steels having high strength and high ductility and excellent strength-ductility balance. It was.
比較のため、表１および４に示す成分組成、金属組織、引張強さの鋼を、表５に示す組み合わせで第１の層および第２の層とし、これを表６(表５のつづき)に示す各層層厚、積層層数、合計層厚となるように積層体を形成し、この積層体を、表５に示す条件で圧延及び／または熱処理し一体化することにより、比較例２１〜２５として示す比較例の複層鋼を製造した。
得られた比較例２１〜２５の比較例複層鋼についての、ｔ１／ｔ２の値、ＴＳ２／ＴＳ１の値、さらに、複層鋼全体としての引張強さ（ＭＰａ）、伸び（％）および強度−延性バランス指標値（引張強さ（ＭＰａ）×伸び（％）の値）を、表６に示す。
For comparison, steels having the composition, metallographic structure, and tensile strength shown in Tables 1 and 4 were used as the first layer and the second layer in the combinations shown in Table 5, and this is shown in Table 6 (continued in Table 5). By forming a laminate so that each layer layer thickness, the number of laminated layers, and the total layer thickness shown in FIG. 1 are obtained, and by integrating the laminate by rolling and / or heat treatment under the conditions shown in Table 5, Comparative Examples 21 to 21 were performed. A comparative multilayer steel shown as 25 was produced.
Obtained for Comparative Example multilayered steel of Comparative Example 21 to 25 was a value of t 1 / t 2, TS 2 /
実施例１〜１２の結果と、比較例２１〜２５の結果を対比してみると、
比較例２１は、実施例１とｔ１／ｔ２が異なるだけであるが、ｔ１／ｔ２が１．２以下になると、低強度で強度−延性バランスが劣っていることがわかる。また比較例２２は、実施例１と比較して第１の層の強度が低く、ＴＳ２／ＴＳ１が６超であるため、強度に対して延性の低下が大きく、強度−延性バランスが低下している。比較例２３は、実施例４と比較して、ｔ１／ｔ２が低いため、高強度ではあるものの、延性が低下し、強度−延性バランスが低下している。
When comparing the results of Examples 1 to 12 with the results of Comparative Examples 21 to 25,
Comparative Example 21, although Example 1 and t 1 / t 2 is different only if
以上の結果からわかるように、本発明の複層鋼は、すぐれた高強度およびすぐれた延性を相兼ね備え、しかも、強度−延性バランスにすぐれたものであることから、例えば、自動車用材料のように軽量でかつ高強度、良加工性が要求される材料としては好適なものといえる。 As can be seen from the above results, the multi-layer steel of the present invention has excellent high strength and excellent ductility, and also has an excellent balance between strength and ductility. Therefore, it can be said that it is suitable as a material that is lightweight, requires high strength and good workability.
Claims (6)
Ｃ：０．０００１〜０．１０％、
Ｓｉ：０．０１〜２．０％、
Ｍｎ：０．０１〜２．０％
を含有し、残部鉄及び不可避的不純物からなる炭素鋼であり、
第２の層が、質量％で、
Ｃ：０．１２〜０．４％、
Ｓｉ：０．０５〜３．０％、
Ｍｎ：０．０５〜３．０％
を含有し、残部鉄及び不可避的不純物からなる炭素鋼であることを特徴とする請求項１〜３のいずれか一項に記載の複層鋼。 The first layer is, by weight,
C: 0.0001 to 0.10%,
Si: 0.01 to 2.0%,
Mn: 0.01 to 2.0%
Is a carbon steel composed of the balance iron and inevitable impurities,
The second layer is, by weight,
C: 0.12-0.4%
Si: 0.05-3.0%,
Mn: 0.05 to 3.0%
The multi-layer steel according to any one of claims 1 to 3, wherein the steel is a carbon steel made of iron and inevitable impurities.
Ｎｂ：０．００１〜０．１％、
Ｔｉ：０．００１〜０．１％、
Ｖ：０．００１〜０．５％、
Ｃｒ：０．００１〜０．０１％、
Ｎｉ：０．００１〜０．０１％、
Ｍｏ：０．０１〜３．０％、
Ｃｕ：０．０１〜１．０％、
の１種又は２種以上をさらに含有する低合金鋼であることを特徴とする請求項４記載の複層鋼。 The first layer is, by weight,
Nb: 0.001 to 0.1%,
Ti: 0.001 to 0.1%,
V: 0.001 to 0.5%,
Cr: 0.001 to 0.01%,
Ni: 0.001 to 0.01%
Mo: 0.01 to 3.0%,
Cu: 0.01 to 1.0%,
The multi-layer steel according to claim 4, which is a low alloy steel further containing one or more of the following.
Ｎｂ：０．００１〜０．１％、
Ｔｉ：０．００１〜０．１％、
Ｖ：０．００１〜０．５％、
Ｃｒ：０．００１〜２．０％、
Ｎｉ：０．００１〜２．５％、
Ｍｏ：０．０１〜１．０％、
Ｃｕ：０．０１〜１．０％、
の１種又は２種以上をさらに含有する低合金鋼であることを特徴とする請求項４または５記載の複層鋼。 The second layer is, by weight,
Nb: 0.001 to 0.1%,
Ti: 0.001 to 0.1%,
V: 0.001 to 0.5%,
Cr: 0.001 to 2.0%,
Ni: 0.001 to 2.5%,
Mo: 0.01 to 1.0%,
Cu: 0.01 to 1.0%,
The multilayer steel according to claim 4 or 5, wherein the steel is a low alloy steel further containing one or more of the following.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008083453A JP4960289B2 (en) | 2008-03-27 | 2008-03-27 | Double layer steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008083453A JP4960289B2 (en) | 2008-03-27 | 2008-03-27 | Double layer steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2009233708A true JP2009233708A (en) | 2009-10-15 |
| JP4960289B2 JP4960289B2 (en) | 2012-06-27 |
Family
ID=41248338
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2008083453A Active JP4960289B2 (en) | 2008-03-27 | 2008-03-27 | Double layer steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4960289B2 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104401063A (en) * | 2014-12-04 | 2015-03-11 | 常熟宝成五金制品有限公司 | High-intensity stainless spring steel |
| CN104441837A (en) * | 2014-12-04 | 2015-03-25 | 常熟市佳泰金属材料有限公司 | Flange forging piece without easy conduction for ship |
| JP2017512247A (en) * | 2013-12-20 | 2017-05-18 | ティッセンクルップ スチール ヨーロッパ アーゲーＴｈｙｓｓｅｎｋｒｕｐｐ Ｓｔｅｅｌ Ｅｕｒｏｐｅ Ａｇ | Steel plate products, steel parts manufactured from these steel plate products, and automobile bodies |
| JP2017535668A (en) * | 2014-10-02 | 2017-11-30 | ティッセンクルップ スチール ヨーロッパ アクチェンゲゼルシャフトＴｈｙｓｓｅｎＫｒｕｐｐ Ｓｔｅｅｌ Ｅｕｒｏｐｅ ＡＧ | Multi-layer flat steel products and components made from multi-layer flat steel products |
| WO2018210574A1 (en) * | 2017-05-16 | 2018-11-22 | Thyssenkrupp Steel Europe Ag | Three-layer high-strength steel or ballistic steel, method for producing a component, and use thereof |
| WO2019130914A1 (en) * | 2017-12-28 | 2019-07-04 | Ｊｆｅスチール株式会社 | Cladded steel plate |
| JP2019519674A (en) * | 2016-04-26 | 2019-07-11 | 宝山鋼鉄股▲分▼有限公司 | Protective steel plate having excellent cold bending performance and method of manufacturing the same |
| JPWO2021186510A1 (en) * | 2020-03-16 | 2021-09-23 |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102017208251A1 (en) * | 2017-05-16 | 2018-11-22 | Thyssenkrupp Ag | Safety steel or wear-resistant steel and use |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05156355A (en) * | 1991-12-04 | 1993-06-22 | Nippon Steel Corp | Manufacture of double-layered steel having low yield ratio |
| JPH05245656A (en) * | 1992-03-09 | 1993-09-24 | Sumitomo Metal Ind Ltd | Manufacture of isotropic metallic laminated body from anisotropic blank |
| JPH06264180A (en) * | 1993-03-09 | 1994-09-20 | Nippon Steel Corp | Cold rolled steel sheet excellent in dent resistance, surface distortion resistance, and workability and its production |
| WO2007138752A1 (en) * | 2006-06-01 | 2007-12-06 | Honda Motor Co., Ltd. | High-strength steel sheet and process for producing the same |
-
2008
- 2008-03-27 JP JP2008083453A patent/JP4960289B2/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05156355A (en) * | 1991-12-04 | 1993-06-22 | Nippon Steel Corp | Manufacture of double-layered steel having low yield ratio |
| JPH05245656A (en) * | 1992-03-09 | 1993-09-24 | Sumitomo Metal Ind Ltd | Manufacture of isotropic metallic laminated body from anisotropic blank |
| JPH06264180A (en) * | 1993-03-09 | 1994-09-20 | Nippon Steel Corp | Cold rolled steel sheet excellent in dent resistance, surface distortion resistance, and workability and its production |
| WO2007138752A1 (en) * | 2006-06-01 | 2007-12-06 | Honda Motor Co., Ltd. | High-strength steel sheet and process for producing the same |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2017512247A (en) * | 2013-12-20 | 2017-05-18 | ティッセンクルップ スチール ヨーロッパ アーゲーＴｈｙｓｓｅｎｋｒｕｐｐ Ｓｔｅｅｌ Ｅｕｒｏｐｅ Ａｇ | Steel plate products, steel parts manufactured from these steel plate products, and automobile bodies |
| JP2017535668A (en) * | 2014-10-02 | 2017-11-30 | ティッセンクルップ スチール ヨーロッパ アクチェンゲゼルシャフトＴｈｙｓｓｅｎＫｒｕｐｐ Ｓｔｅｅｌ Ｅｕｒｏｐｅ ＡＧ | Multi-layer flat steel products and components made from multi-layer flat steel products |
| CN104401063A (en) * | 2014-12-04 | 2015-03-11 | 常熟宝成五金制品有限公司 | High-intensity stainless spring steel |
| CN104441837A (en) * | 2014-12-04 | 2015-03-25 | 常熟市佳泰金属材料有限公司 | Flange forging piece without easy conduction for ship |
| JP2019519674A (en) * | 2016-04-26 | 2019-07-11 | 宝山鋼鉄股▲分▼有限公司 | Protective steel plate having excellent cold bending performance and method of manufacturing the same |
| US10894388B2 (en) | 2016-04-26 | 2021-01-19 | Baoshan Iron & Steel Co., Ltd. | Protective steel plate with excellent cold-bend processing performance and method for manufacturing same |
| WO2018210574A1 (en) * | 2017-05-16 | 2018-11-22 | Thyssenkrupp Steel Europe Ag | Three-layer high-strength steel or ballistic steel, method for producing a component, and use thereof |
| WO2019130914A1 (en) * | 2017-12-28 | 2019-07-04 | Ｊｆｅスチール株式会社 | Cladded steel plate |
| JP6573060B1 (en) * | 2017-12-28 | 2019-09-11 | Ｊｆｅスチール株式会社 | Clad steel plate |
| JPWO2021186510A1 (en) * | 2020-03-16 | 2021-09-23 | ||
| WO2021186510A1 (en) * | 2020-03-16 | 2021-09-23 | 日本製鉄株式会社 | Steel plate |
| JP7273354B2 (en) | 2020-03-16 | 2023-05-15 | 日本製鉄株式会社 | steel plate |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4960289B2 (en) | 2012-06-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4960289B2 (en) | Double layer steel | |
| JP5221348B2 (en) | Multi-layer steel and method for producing multi-layer steel | |
| CN105829095B (en) | Flat steel product, steel member and body of a motor car made of this flat steel product | |
| JP2009235492A (en) | Multilayer steel, and method for producing the same | |
| US20170297304A1 (en) | Multi-layer flat steel product and component produced therefrom | |
| JP2006176843A (en) | High-strength and low-density steel sheet superior in ductility and manufacturing method therefor | |
| JP2014501841A (en) | Steel strip composite material and manufacturing method thereof | |
| CN109382411B (en) | Clad material and method for producing clad material | |
| JP6033757B2 (en) | Aluminum alloy clad plate and method for producing aluminum alloy clad structure member | |
| JP2013122072A (en) | High-yield-ratio high-strength cold-rolled steel sheet of excellent elongation and stretch-flangeability, and method of producing the same | |
| US20080251389A1 (en) | Metal Laminate | |
| WO2016152944A1 (en) | Aluminum-alloy-clad plate and aluminum-alloy-clad structural member | |
| WO2020004410A1 (en) | Clad steel sheet and production method thereof | |
| JP2006200020A (en) | Steel member for vehicle and manufacturing method therefor | |
| JP5094325B2 (en) | High strength composite metal material and manufacturing method thereof | |
| KR102098483B1 (en) | Low density steel clad sheet having excellent formability and fatigue property, and method for manufacturing the same | |
| JP6390567B2 (en) | Manufacturing method of stainless clad steel plate | |
| KR20230029693A (en) | Multi-layer composite cold-rolled steel sheet and manufacturing method thereof | |
| WO2018099347A1 (en) | Martensitic stainless steel rolled composite steel plate and method of manufacturing same | |
| JP5114672B2 (en) | Laminated steel sheet and manufacturing method thereof | |
| JP2005248320A (en) | 600-1,200 MPa-CLASS HIGH-STRENGTH MEMBER FOR AUTOMOBILE WHICH IS EXCELLENT IN STRENGTH HOMOGENEITY WITHIN THE MEMBER AND ITS MANUFACTURING METHOD | |
| JP2020519765A (en) | Hot forming materials, components, and uses | |
| JP6542649B2 (en) | Aluminum alloy clad plate and aluminum alloy clad structural member | |
| KR20180070383A (en) | High strength clad steel having good delayed fracture resistance | |
| JP5326097B2 (en) | Multi-layer steel with excellent strength-ductility balance without interfacial debonding fracture and necking fracture |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A711 | Notification of change in applicant |
Free format text: JAPANESE INTERMEDIATE CODE: A711 Effective date: 20091106 |
|
| RD02 | Notification of acceptance of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7422 Effective date: 20091109 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20091110 |
|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20100203 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20100518 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20120223 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20120322 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20150330 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4960289 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20150330 Year of fee payment: 3 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |