JPH03130345A - Steel stock excellent in non-ageing characteristic and having low yield ratio and its production - Google Patents
Steel stock excellent in non-ageing characteristic and having low yield ratio and its productionInfo
- Publication number
- JPH03130345A JPH03130345A JP26809089A JP26809089A JPH03130345A JP H03130345 A JPH03130345 A JP H03130345A JP 26809089 A JP26809089 A JP 26809089A JP 26809089 A JP26809089 A JP 26809089A JP H03130345 A JPH03130345 A JP H03130345A
- Authority
- JP
- Japan
- Prior art keywords
- less
- steel
- yield ratio
- low yield
- cooling
- 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 57
- 239000010959 steel Substances 0.000 title claims abstract description 57
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 230000032683 aging Effects 0.000 title abstract description 6
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 12
- 238000001816 cooling Methods 0.000 claims abstract description 11
- 238000005096 rolling process Methods 0.000 claims abstract description 11
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 10
- 239000012535 impurity Substances 0.000 claims abstract description 9
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 8
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 8
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 7
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 7
- 238000010438 heat treatment Methods 0.000 claims abstract description 6
- 239000000463 material Substances 0.000 claims description 22
- 230000003679 aging effect Effects 0.000 claims description 14
- 229910052802 copper Inorganic materials 0.000 claims description 5
- 229910052742 iron Inorganic materials 0.000 claims description 5
- 229910052804 chromium Inorganic materials 0.000 claims description 4
- 229910052750 molybdenum Inorganic materials 0.000 claims description 4
- 229910052759 nickel Inorganic materials 0.000 claims 2
- 238000005482 strain hardening Methods 0.000 abstract description 10
- 238000000034 method Methods 0.000 abstract description 4
- 239000000203 mixture Substances 0.000 abstract description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000005728 strengthening Methods 0.000 description 4
- 229910000532 Deoxidized steel Inorganic materials 0.000 description 3
- 239000010953 base metal Substances 0.000 description 3
- 238000005266 casting Methods 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 230000003749 cleanliness Effects 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 229910000885 Dual-phase steel Inorganic materials 0.000 description 1
- 229910000746 Structural steel Inorganic materials 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000003712 anti-aging effect Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は非時効性に優れた低降伏比鋼材およびその製造
方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a low yield ratio steel material with excellent non-aging properties and a method for producing the same.
（従来の技術）
近年、建築用構造物に使用される鋼材（鋼板、鋼管ある
いは形鋼ほか）をはじめとする構造用鋼材において、耐
震性に優れた低降伏比鋼が要求されており、種々の低降
伏比鋼材ならびにその製造方法の提案がなされている。(Prior art) In recent years, low yield ratio steel with excellent earthquake resistance has been required for structural steel materials, including steel materials (steel plates, steel pipes, steel sections, etc.) used in architectural structures. Low yield ratio steel materials and their manufacturing methods have been proposed.
その解決の手段は、軟質相と硬質相の組合せ、すなわち
２相鋼化によるものが殆どであり、たとえば、フェライ
ト−マルテンサイト（あるいはベイナイト）２相鋼化に
よる低降伏比化の例として、特公平１−１６８８８号、
特公昭５８−１０４４２号公報が上げられる。The solution to this problem is mostly by combining a soft phase and a hard phase, that is, by creating a dual-phase steel. Hei 1-16888,
Japanese Patent Publication No. 58-10442 is mentioned.
しかしながら、これらの鋼材は圧延まま（製造まま）で
は良好な低降伏比を有するが、曲げ加工あるいは造管加
工等の冷間加工を受けると歪時効により降伏比が著しく
増大し、所期の特性（低降伏比）を満足し得なくなると
いう問題点があった。However, although these steel materials have a good low yield ratio when rolled (as manufactured), when subjected to cold working such as bending or pipe forming, the yield ratio increases significantly due to strain aging, and the desired properties are lost. There was a problem that it became impossible to satisfy (low yield ratio).
（発明が解決しようとする課題）
本発明の目的は、冷間加工によっても時効を起こさない
、すなわち冷間加工後も良好な低降伏比を確保できる、
非時効性に優れた高強度低降伏比鋼材ならびにその製造
方法を提供するものである。(Problems to be Solved by the Invention) The object of the present invention is to provide a system that does not cause aging even after cold working, that is, can maintain a good low yield ratio even after cold working.
The present invention provides a high-strength, low-yield ratio steel material with excellent non-aging properties and a method for manufacturing the same.
（課題を解決するための手段）
本発明の要旨とするところは重量％で、Ｃ：０．０２〜
０．０５％、Ｓ ｉ：２．５％以下、Ｍｎ：２．０％以
下、Ｐ ： ０．０３％以下、Ｓ ： ０．０１％以下
、Ａρ： ０．１０％以下、Ｎ ：０．００１〜０．０
１０％でかつＴｉを（Ｔｉ−３，４Ｎ）／Ｃ−４〜６と
し、必要に応じてこれにＮｉ：Ｌ、０％以下、Ｃｕ：１
．０％以下、Ｃｒ：１．０％以下、Ｍｏ：１．０％以下
、Ｃａ：ｏ、０００５〜０．００５％のうちいずれか１
８ｉ１または２種以上をさらに含有し、残部がＦｅおよ
び不可避的不純物からなることを特徴とする非時効性に
優れた低降伏比鋼材である。(Means for Solving the Problems) The gist of the present invention is C: 0.02 to 0.02% by weight.
0.05%, Si: 2.5% or less, Mn: 2.0% or less, P: 0.03% or less, S: 0.01% or less, Aρ: 0.10% or less, N: 0. 001~0.0
10% and Ti (Ti-3,4N)/C-4~6, if necessary, add Ni:L, 0% or less, Cu:1
．． 0% or less, Cr: 1.0% or less, Mo: 1.0% or less, Ca: o, any one of 0005 to 0.005%
This is a low yield ratio steel material with excellent non-aging properties, which further contains 8i1 or 2 or more, with the remainder consisting of Fe and unavoidable impurities.
更に本発明は重量％で、Ｃ： ０．０２〜０．０５％、
Ｓ ｉ：２．５％以下、Ｍｎ：２．０％以下、Ｐ ：
０．０３％以下、Ｓ ： ０．０１％以下、Ａｎ：ｏ、
ｔｏ％以下、Ｎ：０．００１〜ｏ、ｏｔｏ％でかつＴｉ
を（Ｔｉ−３，４Ｎ）／Ｃ−４〜６とし、必要に応じて
これにＮ ｉ：１．０％以下、Ｃｕ：１．０％以下、Ｃ
ｒ：１．０％以下、ＭＯ：１．０％以下、Ｃａ：０．ｏ
ｏ０５〜０．００５％のうちいずれか１種、または２種
以上をさらに含有し、残部がＦｅおよび不可避的不純物
からなる鋼片を９００℃以上の温度に加熱後、７００℃
以上の温度で圧延を終了し、以後空冷ないしは加速冷却
することを特徴とする非時効性に優れた低降伏比鋼材の
製造方法である。Further, in the present invention, C: 0.02 to 0.05% by weight,
Si: 2.5% or less, Mn: 2.0% or less, P:
0.03% or less, S: 0.01% or less, An: o,
to% or less, N: 0.001 to o, oto% and Ti
(Ti-3,4N)/C-4 to 6, and if necessary, Ni: 1.0% or less, Cu: 1.0% or less, C
r: 1.0% or less, MO: 1.0% or less, Ca: 0. o
A steel piece further containing any one or more of O05 to 0.005%, with the balance consisting of Fe and unavoidable impurities, is heated to a temperature of 900°C or higher, and then heated to 700°C.
This is a method for producing a low yield ratio steel material with excellent non-aging properties, which is characterized in that rolling is finished at the above temperature and then air cooling or accelerated cooling is performed.
（作 用）
本発明の低降伏比鋼材は冷間加工後も良好な低降伏比を
有することを特徴とする非時効性に優れた高強度低降伏
比鋼材である。従来の低降伏比鋼材では、圧延ままでは
良好な低降伏比を示すものの、ひとたび冷間加工を加え
ると歪時効効果により降伏点が著しく上昇し、冷間加工
ままでは所期の低降伏比を達成し得ないという問題点が
あった。(Function) The low yield ratio steel material of the present invention is a high strength low yield ratio steel material with excellent non-aging properties, which is characterized by having a good low yield ratio even after cold working. Conventional low yield ratio steel exhibits a good low yield ratio when rolled, but once cold worked, the yield point increases significantly due to the strain aging effect, making it difficult to achieve the desired low yield ratio when cold worked. The problem was that it could not be achieved.
この問題点を解決するため、非時効性に優れ、かつ低降
伏比を満足するとともに所要の強度レベルを確保すると
いう観点からフェライト単相鋼の有する特性を最大限に
活用することを試みた。In order to solve this problem, we attempted to make the most of the characteristics of ferritic single phase steel from the viewpoint of having excellent non-aging properties, satisfying a low yield ratio, and securing the required strength level.
以下、本発明鋼材における化学成分の限定理由について
説明する。The reason for limiting the chemical components in the steel material of the present invention will be explained below.
まず、非時効性に関しては、時効を生じる原因となる侵
入型固溶原子であるＣならびにＮの固定化が必須である
。本発明においてはＴ１によるＣ１Ｎの固定化を試みた
。すなわち、ＴｉをＣ，Ｎの当量以上添加することによ
りＣ，Ｎの固定化を計った（（Ｔｉ−３，４Ｎ）／Ｃ≧
４）。First, regarding non-aging properties, it is essential to immobilize C and N, which are interstitial solid solution atoms that cause aging. In the present invention, an attempt was made to immobilize C1N using T1. That is, the immobilization of C and N was attempted by adding Ti in an amount equal to or more than that of C and N ((Ti-3,4N)/C≧
4).
一方、Ｔｉを過量に添加するとＴｉＣの粗大化が起こり
、ＴｉＣによる析出強化が利用できなくなるため、高強
度化が困難となる。そこで、ＴｉとＣ，Ｈの適正なバラ
ンス域を（Ｔｉ−３，４Ｎ）／Ｃ−４〜６とした。On the other hand, if an excessive amount of Ti is added, the TiC will become coarse, making it impossible to utilize precipitation strengthening by TiC, making it difficult to increase the strength. Therefore, the appropriate balance range for Ti, C, and H was set as (Ti-3,4N)/C-4 to 6.
Ｃ量は非時効性という観点からは少ない方が好ましい。The smaller the amount of C, the better from the viewpoint of non-aging properties.
しかしながら、溶接性の観点から、その下限を０．０２
％とした。また、ＣＭＬが多くなるとＣを固定するため
のＴｉの添加量が増大し、溶接性を阻害する。そのため
Ｃ量の上限を０．０５％とした。However, from the viewpoint of weldability, the lower limit is set to 0.02
%. Furthermore, as CML increases, the amount of Ti added to fix C increases, which impedes weldability. Therefore, the upper limit of the amount of C was set to 0.05%.
Ｓｌは脱酸上鋼に含まれる元素である。また、固溶強化
によるフェライトマトリックス強化の点で有用である。Sl is an element contained in deoxidized steel. It is also useful in strengthening the ferrite matrix by solid solution strengthening.
一般の炭素鋼ではＳｌの過剰添加は溶接性、ＨＡＺ靭性
を阻害するが、本発明鋼ではＣをＴｉで固定しているた
め、その添加量は２．５％まで可能である。In general carbon steel, excessive addition of Sl impairs weldability and HAZ toughness, but in the steel of the present invention, since C is fixed with Ti, the addition amount can be up to 2.5%.
Ｍｎは脱酸上鋼に含まれる元素である。また、強度、靭
性を確保する上で有用である。しかしＭｎｆｆ１が多す
ぎると溶接性、ＨＡＺ靭性の劣化を招くためその上限を
２．０％とした。Mn is an element contained in deoxidized steel. It is also useful in ensuring strength and toughness. However, too much Mnff1 causes deterioration of weldability and HAZ toughness, so the upper limit was set at 2.0%.
Ｐ、Ｓは不可避的不純物として鋼中に含まれる。P and S are contained in steel as inevitable impurities.
これらは母材ならびに溶接部の靭性を劣化させるため、
その量は極力少ない方が好ましく、本発明鋼ではＰ、Ｓ
の上限量をそれぞれ０．０３％、 ０．０１％以下とし
た。These deteriorate the toughness of the base metal and weld, so
It is preferable that the amount is as small as possible, and in the steel of the present invention, P, S
The upper limit amounts of these are set to 0.03% and 0.01%, respectively.
Ａｌは一般に脱酸上鋼に含まれる元素であるが、Ｓｌお
よびＭｎあるいはＴｉによっても脱酸は行なわれるので
、本発明ではＡρについては下限を限定しない。しかし
、Ａｌ量が多くなると鋼の清浄度が悪くなり、ＨＡＺ靭
性が劣化するので上限を０．１％とした。Al is generally an element contained in deoxidized steel, but since deoxidation is also performed by Sl, Mn, or Ti, the present invention does not limit the lower limit of Aρ. However, if the amount of Al increases, the cleanliness of the steel will deteriorate and the HAZ toughness will deteriorate, so the upper limit was set at 0.1%.
Ｎは一般に不可避的不純物として鋼中に含まれるが、非
時効性の観点からはＮｊｌは少ないことが好ましい。し
かしながら、本発明鋼ではＴｉをＮに対して当量以上添
加しており、Ｎの固定化はＴｉによって十分に行える。Although N is generally contained in steel as an unavoidable impurity, from the viewpoint of anti-aging properties, it is preferable that Njl be small. However, in the steel of the present invention, Ti is added in an amount equal to or more than N, and N can be sufficiently fixed by Ti.
従って、ＴｉＮによるＨＡＺ靭性向上のための必要最小
量として、Ｎ量の下限を０．００１％とした。また、Ｎ
の過量添加はＨＡＺ靭性の劣化を招くため、その上限を
０．０１％とした。Therefore, the lower limit of the amount of N was set at 0.001% as the minimum amount necessary for improving the HAZ toughness by TiN. Also, N
Since excessive addition of C leads to deterioration of HAZ toughness, the upper limit was set at 0.01%.
本発明鋼においては、さらに必要によりＮ目０．０５〜
０．５％、Ｃｕ ： ０．０５〜０．５％、Ｃｒ：１．
０％以下、Ｍｏ：１．０％以下、Ｃａ：ｏ、０００５〜
０．００５％のうちいずれか１種、または２種以上を含
有させる。In the steel of the present invention, if necessary, N mesh 0.05 to
0.5%, Cu: 0.05-0.5%, Cr: 1.
0% or less, Mo: 1.0% or less, Ca: o, 0005~
One or more of these 0.005% are included.
これらの元素を含有させる主たる目的は本発明鋼の特徴
を損なうことなく、強度、靭性の向上および製造板厚の
拡大を可能にするところにあり、その添加量は溶接性お
よびＨＡＺ靭性等の面から自ずと制限されるべき性質の
ものである。The main purpose of containing these elements is to improve the strength and toughness of the steel of the present invention and to increase the thickness of the manufactured plate without impairing the characteristics of the steel.The amount of addition should be determined depending on aspects such as weldability and HAZ toughness. Therefore, it is a property that should naturally be restricted.
ＮｉはＨＡＺの硬化性および靭性に悪影響を与えること
なく母材の強度、靭性を向上させる特性をもつが、１．
０％を超えるとＨＡＺの硬化性および靭性上好ましくな
いため、上限を１．０％とした。Ni has the property of improving the strength and toughness of the base material without adversely affecting the hardenability and toughness of HAZ.
If it exceeds 0%, it is unfavorable in terms of hardenability and toughness of the HAZ, so the upper limit was set at 1.0%.
ＣｕはＮｉとほぼ同様の効果を持つとともに、耐食性、
耐水素誘起割れ特性にも効果がある。しかし、１．０％
を超えると圧延中にＣｕ−クラックが発生し製造が困難
になる。このため、上限を１．０％とした。Cu has almost the same effect as Ni, and also has corrosion resistance,
It is also effective against hydrogen-induced cracking resistance. However, 1.0%
If it exceeds this amount, Cu-cracks will occur during rolling, making manufacturing difficult. Therefore, the upper limit was set at 1.0%.
Ｃｒは母材の強度を高める元素であるが、Ｃ「量が１％
を超えると溶接性やＨＡＺ靭性を劣化させるため、上限
を１．０％とした。Cr is an element that increases the strength of the base metal, but the amount of C is 1%.
If it exceeds 1.0%, weldability and HAZ toughness deteriorate, so the upper limit was set at 1.0%.
Ｍｏは母材の強度、靭性を共に向上させる元素であるが
、１．０％を超えると溶接部靭性および溶接性の劣化を
招き好ましくないため、上限を１．０％とした。Mo is an element that improves both the strength and toughness of the base metal, but if it exceeds 1.0%, it undesirably deteriorates the toughness and weldability of the weld zone, so the upper limit was set at 1.0%.
Ｃａは硫化物の形態を制御し、シャルピー吸収エネルギ
ーを増加させ低温靭性を向上させるほか、耐水素誘起割
れ性の改善にも効果を発揮する。しかし、Ｃａｊｉｌは
０．０００５％未満では実用上効果がなく、また、０．
００５％を超えるとＣａＳ、ＣａＯが多量に生成して大
型介在物となり、鋼の靭性のみならず清浄度も害し、さ
らに溶接性にも悪影響を与えるので、Ｃａ添加量の範囲
を０．０００５〜０．００５％とした。Ca controls the morphology of sulfides, increases Charpy absorbed energy, improves low-temperature toughness, and is also effective in improving hydrogen-induced cracking resistance. However, Cajil has no practical effect at less than 0.0005%;
If it exceeds 0.005%, a large amount of CaS and CaO will be generated and become large inclusions, which will impair not only the toughness but also the cleanliness of the steel, as well as the weldability. It was set to 0.005%.
以上の成分系を有する本発明鋼は、非時効性に優れ、か
つ低降伏比を満足するとともに所要の強度レベルを確保
し得る画期的な低降伏比鋼材である。The steel of the present invention having the above-mentioned composition system is an epoch-making low yield ratio steel material that has excellent non-aging properties, satisfies a low yield ratio, and can secure the required strength level.
次に、以上のような成分系を有する鋼材の製造法につい
て述べる。Next, a method for producing steel having the above-mentioned composition system will be described.
まず、鋼片の加熱温度は９００℃以上とする必要がある
。加熱温度が９００℃未満になると、圧延終了が低くな
りすぎるため、所要の材質が得られなくなる。そこで加
熱温度の下限を９００℃とする必要がある。First, the heating temperature of the steel piece needs to be 900°C or higher. If the heating temperature is less than 900°C, the end of rolling will be too low, making it impossible to obtain the desired material quality. Therefore, it is necessary to set the lower limit of the heating temperature to 900°C.
加熱温度の上限については特に制約されるものではない
が、母材靭性という観点からは１２５０℃以下程度とす
ることが好ましい。なお、鋼片鋳造後Ａ ｒ ａ温度以
下に冷却後再加熱することなく、すなわち鋼片鋳造後直
ちにあるいは鋼片鋳造後Ａ ｒ ａ温度以上での保熱過
程を経た後直ちに圧延を行なってもよい。The upper limit of the heating temperature is not particularly limited, but from the viewpoint of base material toughness, it is preferably about 1250° C. or lower. In addition, even if rolling is carried out without reheating after cooling to below the A ra temperature after casting the billet, that is, immediately after casting the billet or immediately after undergoing a heat retention process at the A ra temperature or higher after casting the billet. good.
圧延終了温度を７００℃以上とする理由は、この温度よ
り低い温度で圧延を行なうとフェライトの加工が過度に
行なわれ、母材靭性が劣化するためである。また、圧延
終了温度の上限は特に制約されるものではないが、靭性
確保の観点からは１０００℃以下とすることが好ましい
。なお圧延後の鋼材の冷却は空冷あるいは加速冷却のい
ずれのプロセスを適用してもよい。The reason why the rolling end temperature is set to 700° C. or higher is that if rolling is performed at a temperature lower than this temperature, the ferrite will be processed excessively and the toughness of the base material will deteriorate. Further, the upper limit of the rolling end temperature is not particularly limited, but from the viewpoint of ensuring toughness, it is preferably 1000° C. or less. Note that the steel material after rolling may be cooled by either air cooling or accelerated cooling.
なお、本発明は種々の鋼材に適用が可能であるが、主と
して引張強度５０〜８０ｋｇ ｆ ／ １１１１１％板
厚ｉｏ。Although the present invention can be applied to various steel materials, it is mainly applicable to tensile strength of 50 to 80 kg f/11111% plate thickness io.
關以下の厚鋼板並びに熱延鋼板に適用されることが好ま
しい。It is preferable to apply this method to thick steel plates and hot rolled steel plates.
（実 施 例）
第１表に供試鋼の化学成分を、第２表に６鋼の製造条件
と、圧延まま並びに冷間加工後の６鋼の機械的性質を示
す。(Example) Table 1 shows the chemical composition of the test steels, and Table 2 shows the manufacturing conditions of the six steels and the mechanical properties of the six steels as rolled and after cold working.
第１．第２表において、鋼Ａ−Ｉは本発明鋼、Ｊ −に
は比較鋼を示す。1st. In Table 2, steel A-I indicates the steel of the present invention, and J- indicates the comparative steel.
本発明鋼Ａ−１は高強度を有するとともに、圧延ままの
みならず１０％の冷間加工後においても８０％以下の極
めて良好な低降伏比を有する。Inventive steel A-1 has high strength and an extremely low yield ratio of 80% or less not only as rolled but also after 10% cold working.
これに対して、比較鋼Ｊは圧延ままでは良好な低降伏比
を示すものの、Ｔｌ量の不足により（ｅＴｌ−３，８）
、Ｃ，Ｎの固定が不十分であり、冷間加工後の降伏比が
９７％と極めて高くなっている。また、比較鋼にはｅＴ
ｉ−７，１とＴｉＪＩが過剰なため、ＴｉＣの粗大化が
生じ強度が著しく低い。比較鋼りはＴｌ量が低く、Ｔｉ
Ｃによる析出強化効果がないため強度が低い。また、Ｃ
，Ｎの固定が不十分なため、冷間加工後の降伏比が９６
％と極めて高くなっている。On the other hand, comparative steel J shows a good low yield ratio as rolled, but due to the lack of Tl (eTl-3,8)
, C, and N are insufficiently fixed, and the yield ratio after cold working is extremely high at 97%. In addition, the comparative steel has eT
Since i-7,1 and TiJI are excessive, TiC becomes coarse and the strength is extremely low. Comparative steel has low Tl content and Ti
Since there is no precipitation strengthening effect due to C, the strength is low. Also, C
, due to insufficient fixation of N, the yield ratio after cold working was 96.
%, which is extremely high.
（発明の効果）
本発明鋼の降伏比は冷間加工後においても極めて低く（
非時効性に優れ）、従来鋼にはない優れた低降伏比特性
を有する。(Effect of the invention) The yield ratio of the steel of the invention is extremely low even after cold working (
It has excellent low yield ratio characteristics not found in conventional steels.
代 理 人teenager Reason Man
Claims (1)
する非時効性に優れた低降伏比鋼材。 ２、重量％で、 Ｎｉ：１．０％以下、 Ｃｕ：１．０％以下、 Ｃｒ：１．０％以下、 Ｍｏ：１．０％以下、 Ｃａ：０．０００５〜０．００５％、 のうちいずれか１種、または２種以上を含有し、残部が
Ｆｅおよび不可避的不純物からなることを特徴とする請
求項１記載の非時効性に優れた低降伏比鋼材。 ３、重量％で、 Ｃ：０．０２〜０．０５％、 Ｓｉ：２．５％以下、 Ｍｎ：２．０％以下、 Ｐ：０．０３％以下、 Ｓ：０．０１％以下、 Ａｌ：０．１０％以下、 Ｎ：０．００１〜０．０１０％、 Ｔｉを（Ｔｉ−３．４Ｎ）／Ｃ＝４〜６、 残部がＦｅおよび不可避的不純物からなる鋼片を９００
℃以上の温度に加熱後、７００℃以上の温度で圧延を終
了し、以後空冷ないしは加速冷却することを特徴とする
非時効性に優れた低降伏比鋼材の製造方法。 ４、重量％で、 Ｎｉ：１．０％以下、 Ｃｕ：１．０％以下、 Ｃｒ：１．０％以下、 Ｍｏ：１．０％以下、 Ｃａ：０．０００５〜０．００５％、 のうちいずれか１種、または２種以上をさらに含有し、
残部がＦｅおよび不可避的不純物からなる鋼片であるこ
とを特徴とする請求項３記載の非時効性に優れた低降伏
比鋼材の製造方法。[Claims] 1. In weight%, C: 0.02 to 0.05%, Si: 2.5% or less, Mn: 2.0% or less, P: 0.03% or less, S: 0 .01% or less, Al: 0.10% or less, N: 0.001 to 0.010%, Ti (Ti-3.4N)/C = 4 to 6, the balance consisting of Fe and inevitable impurities. A low yield ratio steel material with excellent non-aging properties. 2. In weight%, Ni: 1.0% or less, Cu: 1.0% or less, Cr: 1.0% or less, Mo: 1.0% or less, Ca: 0.0005 to 0.005%. 2. The low yield ratio steel material with excellent non-aging properties according to claim 1, characterized in that it contains one or more of these, with the remainder consisting of Fe and unavoidable impurities. 3. In weight%, C: 0.02 to 0.05%, Si: 2.5% or less, Mn: 2.0% or less, P: 0.03% or less, S: 0.01% or less, Al : 0.10% or less, N: 0.001 to 0.010%, Ti (Ti-3.4N)/C = 4 to 6, and the balance is Fe and inevitable impurities.
A method for producing a low yield ratio steel material with excellent non-aging properties, which comprises heating to a temperature of 700°C or higher, finishing rolling at a temperature of 700°C or higher, and then air-cooling or accelerated cooling. 4. In weight%, Ni: 1.0% or less, Cu: 1.0% or less, Cr: 1.0% or less, Mo: 1.0% or less, Ca: 0.0005 to 0.005%. further containing any one or two or more of them,
4. The method for producing a low yield ratio steel material with excellent non-aging properties according to claim 3, wherein the remaining portion is a steel piece consisting of Fe and unavoidable impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1268090A JP2599466B2 (en) | 1989-10-17 | 1989-10-17 | Low yield ratio structural steel excellent in non-aging property and method of manufacturing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1268090A JP2599466B2 (en) | 1989-10-17 | 1989-10-17 | Low yield ratio structural steel excellent in non-aging property and method of manufacturing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03130345A true JPH03130345A (en) | 1991-06-04 |
| JP2599466B2 JP2599466B2 (en) | 1997-04-09 |
Family
ID=17453752
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1268090A Expired - Fee Related JP2599466B2 (en) | 1989-10-17 | 1989-10-17 | Low yield ratio structural steel excellent in non-aging property and method of manufacturing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2599466B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013088692A1 (en) * | 2011-12-12 | 2013-06-20 | Ｊｆｅスチール株式会社 | Steel sheet with excellent aging resistance, and method for producing same |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56142852A (en) * | 1980-04-09 | 1981-11-07 | Nippon Steel Corp | High strength cold rolled steel plate of low yield ratio for deep drawing |
| JPS63206451A (en) * | 1987-02-23 | 1988-08-25 | Nisshin Steel Co Ltd | Cold rolled soft steel sheet having superior weldability |
-
1989
- 1989-10-17 JP JP1268090A patent/JP2599466B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56142852A (en) * | 1980-04-09 | 1981-11-07 | Nippon Steel Corp | High strength cold rolled steel plate of low yield ratio for deep drawing |
| JPS63206451A (en) * | 1987-02-23 | 1988-08-25 | Nisshin Steel Co Ltd | Cold rolled soft steel sheet having superior weldability |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013088692A1 (en) * | 2011-12-12 | 2013-06-20 | Ｊｆｅスチール株式会社 | Steel sheet with excellent aging resistance, and method for producing same |
| JP5569657B2 (en) * | 2011-12-12 | 2014-08-13 | Ｊｆｅスチール株式会社 | Steel sheet with excellent aging resistance and method for producing the same |
| JPWO2013088692A1 (en) * | 2011-12-12 | 2015-04-27 | Ｊｆｅスチール株式会社 | Steel sheet with excellent aging resistance and method for producing the same |
| US9828648B2 (en) | 2011-12-12 | 2017-11-28 | Jfe Steel Corporation | Steel sheet with excellent aging resistance property and method for producing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2599466B2 (en) | 1997-04-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4022958B2 (en) | High toughness thick steel plate with excellent weld heat affected zone toughness and method for producing the same | |
| JPH0823048B2 (en) | Method for producing hot rolled steel sheet with excellent bake hardenability and workability | |
| JPH10195591A (en) | High strength hot rolled steel sheet for thermal hardening excellent in stretch-flanging property and its production | |
| JPH05105957A (en) | Production of heat resistant high strength bolt | |
| JP3290595B2 (en) | Method for manufacturing high-tensile steel plate with excellent toughness and weldability | |
| JPH06128631A (en) | Production of high manganese ultrahigh tensile strength steel excellent in low temperature toughness | |
| JP3218442B2 (en) | Manufacturing method of mechanical structural steel with excellent delayed fracture resistance | |
| JP3635803B2 (en) | Method for producing high-tensile steel with excellent toughness | |
| JP2828755B2 (en) | Manufacturing method of low yield ratio 80 ▲ kgｆf / ▲ mm ▼▼ 2 上 class steel sheet with excellent weldability | |
| JPH03130345A (en) | Steel stock excellent in non-ageing characteristic and having low yield ratio and its production | |
| JPH02163341A (en) | Steel material for structural purposes having excellent fire resistance and its manufacture | |
| JPH0717947B2 (en) | Low yield ratio high strength steel sheet manufacturing method | |
| JPH02240242A (en) | Stainless steel wire having excellent high strength characteristics and its manufacture | |
| JPS61124524A (en) | Manufacture of bar steel for steel reinforced concrete | |
| JPH0215145A (en) | Working and heating hardened hot rolled steel plate | |
| JPH11209823A (en) | Manufacture of high strength steel sheet excellent in press formability | |
| JP3956634B2 (en) | Steel sheet with excellent toughness and method for producing the same | |
| JP2000096137A (en) | Production of steel having fine crystal grain structure | |
| JPH06293913A (en) | Production of steel plate excellent in toughness at low temperature | |
| JPH0641633A (en) | Method for working high tensile strength steel small in rise of yield ratio | |
| JPH07207334A (en) | Production of high tension steel having excellent weldability and plastic deformability | |
| JPH06256845A (en) | Production of high-strength electric resistance welded tube | |
| JPH04314823A (en) | Production of high tensile strength steel excellent in plastic deformability and having high young's modulus | |
| JPH042718A (en) | Production of medium strength steel plate having high yield point and high toughness | |
| JPH1088277A (en) | Non-heat treated high tensile strength thick steel material and its production |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090109 Year of fee payment: 12 |
|
| LAPS | Cancellation because of no payment of annual fees |