JPH06306543A - High strength pc wire rod excellent in delayed fracture resistance and its production - Google Patents
High strength pc wire rod excellent in delayed fracture resistance and its productionInfo
- Publication number
- JPH06306543A JPH06306543A JP11115193A JP11115193A JPH06306543A JP H06306543 A JPH06306543 A JP H06306543A JP 11115193 A JP11115193 A JP 11115193A JP 11115193 A JP11115193 A JP 11115193A JP H06306543 A JPH06306543 A JP H06306543A
- Authority
- JP
- Japan
- Prior art keywords
- strength
- delayed fracture
- fracture resistance
- mpa
- wire
- 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.)
- Withdrawn
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、建設用等に用いられる
優れた耐遅れ破壊特性を示す高張力ＰＣ棒線とその製造
方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength PC rod wire having excellent delayed fracture resistance used for construction and the like and a method for producing the same.
【０００２】[0002]
【従来の技術】近年、構造物の大型化に伴い引張強さ１
５００ＭＰａ以上のＰＣ鋼線の開発が要求されてきてい
る。しかし、引張強度が１２００ＭＰａを超えると遅れ
破壊の危険性が高まることがよく知られており、例えば
ボルト鋼等に於いては、現在使用されている強度は１１
００ＭＰａ級が上限となっているのが現状である。2. Description of the Related Art In recent years, tensile strength has increased with the increase in size of structures.
Development of PC steel wire of 500 MPa or more has been required. However, it is well known that the risk of delayed fracture increases when the tensile strength exceeds 1200 MPa. For example, in the case of bolt steel, the strength currently used is 11
At present, the upper limit is the 00 MPa class.
【０００３】遅れ破壊の対策として、従来、高強度ボル
ト用鋼において数々の研究開発がなされているが、例え
ば、特開平３−２４３７４４号公報、特開平３−２４３
７４５号公報に、それぞれ重量％で、Ｃ＝０．３０〜
０．５０、Ｓｉ＝０．０５〜０．５０、Ｍｎ＜０．５
０、Ｃｒ＝０．１〜５．０、Ａｌ＝０．００５〜０．１
０、Ｎｂ＝０．００５〜０．２０、Ｃｕ＝０．０１〜
０．６０、Ｍｏ＝０．０１〜０．８０、Ｎ＝０．００５
〜０．３０、及びＣ＝０．３５〜０．５０、Ｓｉ＜０．
２０、Ｍｎ＜０．３５、Ｃｒ＜０．２５、Ａｌ＝０．０
０５〜０．１０、Ｖ＝０．０５〜０．５０、Ｎｂ＝０．
００５〜０．２０、Ｔｉ＜０．１０、Ｚｒ＜０．１５、
Ｃｕ＝０．０５〜０．６０、Ｎｉ＝１．０〜３．０、Ｍ
ｏ＝０．４〜１．５の化学成分を含有する高強度鋼及び
その製造方法が記載されている。これらの発明は、遅れ
破壊クラックがオーステナイト粒界を起点及び伝播径路
として発生する事に注目し、粒界偏析元素の低減、粒の
細粒化等により粒界強化を図り、耐遅れ破壊性を改善す
るものである。As measures against delayed fracture, various researches and developments have been conventionally made on steel for high-strength bolts. For example, JP-A-3-243744 and JP-A-3-243 are known.
No. 745, C = 0.30-wt%, respectively.
0.50, Si = 0.05 to 0.50, Mn <0.5
0, Cr = 0.1-5.0, Al = 0.005-0.1
0, Nb = 0.005 to 0.20, Cu = 0.01 to
0.60, Mo = 0.01 to 0.80, N = 0.005
.About.0.30, and C = 0.35 to 0.50, Si <0.
20, Mn <0.35, Cr <0.25, Al = 0.0
05 to 0.10, V = 0.05 to 0.50, Nb = 0.
005 to 0.20, Ti <0.10, Zr <0.15,
Cu = 0.05-0.60, Ni = 1.0-3.0, M
A high-strength steel containing a chemical composition of o = 0.4 to 1.5 and a manufacturing method thereof are described. These inventions pay attention to the fact that delayed fracture cracks occur at the austenite grain boundary as a starting point and a propagation path, reduce the grain boundary segregation element, strengthen the grain boundary by making the grains finer, and delay fracture resistance. It will improve.
【０００４】又、ＰＣ鋼棒の遅れ破壊特性を改善する手
段が特開昭４９−９０２０７号公報に記載されている。
この発明は、炭素含有量０．２０〜０．９０％の鋼材を
熱間圧延後あるいは熱間圧延冷却後Ａ3 変態点以上に再
加熱後強制空冷を施し、マルテンサイト量を３０％以下
に抑制し、主組織をパーライト、ベーナイトまたはフェ
ライトとする事によりＰＣ鋼棒の遅れ破壊特性の改善を
図るものである。A means for improving the delayed fracture characteristics of PC steel rods is described in Japanese Patent Application Laid-Open No. 49-90207.
According to the present invention, a steel material having a carbon content of 0.20 to 0.90% is hot-rolled or hot-rolled and cooled, and then reheated to an A 3 transformation point or higher and then forced air cooling is performed to reduce the amount of martensite to 30% or less. By suppressing and by making pearlite, bainite or ferrite the main structure, the delayed fracture property of the PC steel bar is improved.
【０００５】[0005]
【発明が解決しようとする課題】特開平３−２４３７４
４号公報及び特開平３−２４３７４５号公報記載の発明
は、窒素含有量及び窒化物を形成する合金元素の含有量
を規定する事により、再加熱時のオーステナイト粒の粗
大化を抑制するものである。しかし、この技術により得
られるオーステナイト粒径の微細化度合いには限界があ
る為、ＰＣ鋼線に応用した場合、その遅れ破壊特性の改
善にも自ずと限界がある。[Patent Document 1] Japanese Patent Application Laid-Open No. 3-24374
The inventions described in JP-A No. 4 and JP-A-3-243745 suppress the coarsening of austenite grains during reheating by defining the nitrogen content and the content of alloying elements that form nitrides. is there. However, since there is a limit to the degree of refinement of the austenite grain size obtained by this technique, when it is applied to a PC steel wire, there is also a limit to the improvement of its delayed fracture property.
【０００６】また、特開昭４９−９０２０７号公報記載
の発明の様に、遅れ破壊の起点となるマルテンサイトの
含有量を規定しても、その組織を積極的に微細化しない
のでは大幅な遅れ破壊特性改善にはつながらない。Further, even if the content of martensite, which is the starting point of delayed fracture, is regulated as in the invention described in JP-A-49-90207, it will be significant if the structure is not actively refined. It does not lead to the improvement of delayed fracture characteristics.
【０００７】[0007]
【課題を解決するための手段】本発明の要旨は以下の通
りである。The gist of the present invention is as follows.
【０００８】 化学成分として、重量％で、Ｃ：０．
１０〜０．３９％、Ｓｉ：０．１０〜３．０％、Ｍｎ：
０．２〜１．５％、Ａｌ：０．００５〜０．１０％を含
有し、残部鉄及び不可避的不純物から成り、組織がオー
ステナイト粒度番号で１０番以上及び下部ベーナイトの
比率が４０％以上である事を特徴とする１５００ＭＰａ
の強度を有する耐遅れ破壊特性に優れた高強度ＰＣ棒
線。As a chemical component, C: 0.
10 to 0.39%, Si: 0.10 to 3.0%, Mn:
0.2 to 1.5%, Al: 0.005 to 0.10%, balance iron and unavoidable impurities, the structure is austenite grain size number 10 or more and lower bainite ratio is 40% or more. 1500 MPa characterized by being
High strength PC bar wire with excellent strength and delayed fracture resistance.
【０００９】 化学成分として、重量％で、Ｃ：０．
１０〜０．３９％、Ｓｉ：０．１０〜３．０％、Ｍｎ：
０．２〜１．５％、Ａｌ：０．００５〜０．１０％を含
有し、その他強化元素としてＣｒ：０．１〜２．０％、
Ｍｏ：０．０１〜２．０％、Ｖ：０．０１〜１．０％、
Ｗ：０．０１〜２．０％、Ｎｉ：０．１〜２．０％、Ｃ
ｕ：０．１〜２．０％、Ｔｉ：０．０１〜０．５％、Ｎ
ｂ：０．０１〜０．５％、Ｂ：０．０００２〜０．００
５％の１種類または２種類以上を含有し、残部鉄及び不
可避的不純物から成り、組織がオーステナイト粒度番号
で１０番以上及び下部ベーナイトの比率が４０％以上で
ある事を特徴とする１５００ＭＰａの強度を有する耐遅
れ破壊特性に優れた高強度ＰＣ棒線。As a chemical component, C: 0.
10 to 0.39%, Si: 0.10 to 3.0%, Mn:
0.2 to 1.5%, Al: 0.005 to 0.10%, Cr: 0.1 to 2.0% as other strengthening element,
Mo: 0.01 to 2.0%, V: 0.01 to 1.0%,
W: 0.01 to 2.0%, Ni: 0.1 to 2.0%, C
u: 0.1 to 2.0%, Ti: 0.01 to 0.5%, N
b: 0.01 to 0.5%, B: 0.0002 to 0.00
Strength of 1500 MPa, characterized by containing 5% of 1 type or 2 types or more, consisting of balance iron and unavoidable impurities, and having a structure of austenite grain size number of 10 or more and lower bainite ratio of 40% or more. High strength PC bar wire with excellent delayed fracture resistance.
【００１０】 前記またはの１５００ＭＰａの強
度を有する耐遅れ破壊特性に優れた高強度ＰＣ棒線の製
造方法において、前記成分を含有する鋼片を加熱条件９
５０℃以上１２００℃以下、仕上げ温度６００℃以上９
５０℃以下で棒線に圧延後、Ｍｓ点±２００℃の範囲で
オーステンパー処理する事を特徴とする１５００ＭＰａ
の強度を有する耐遅れ破壊特性に優れた高強度ＰＣ棒線
の製造方法。In the method for producing a high-strength PC rod wire having the above-mentioned or 1500 MPa strength and excellent in delayed fracture resistance, a steel slab containing the above components is heated under a heating condition 9
50 ℃ to 1200 ℃, finishing temperature 600 ℃ to 9
1500 MPa characterized by austempering at Ms point ± 200 ° C after rolling into a bar at 50 ° C or less
And a method for producing a high-strength PC rod wire having excellent delayed fracture resistance.
【００１１】 前記またはの１５００ＭＰａの強
度を有する耐遅れ破壊特性に優れた高強度ＰＣ棒線の製
造方法において、前記成分を含有する鋼片を加熱条件９
５０℃以上１２００℃以下、仕上げ温度６００℃以上９
５０℃以下で棒線に圧延後、直ちにＭｓ点±２００℃の
範囲でオーステンパー処理し、更に２５０℃以上の温度
及び１秒以上の時間でＴ（２０＋ｌｏｇ10ｔ）≧１００
００（Ｔ：焼戻し温度（Ｋ）、ｔ：焼戻し時間（時
間））を満足する様に焼戻し処理する事を特徴とする１
５００ＭＰａの強度を有する耐遅れ破壊特性に優れた高
強度ＰＣ棒線の製造方法。In the method for producing a high-strength PC rod wire having the above-mentioned or 1500 MPa strength and excellent in delayed fracture resistance, a steel slab containing the above components is heated under a heating condition 9
50 ℃ to 1200 ℃, finishing temperature 600 ℃ to 9
Immediately after rolling into a bar at 50 ° C or less, austempering is performed within the range of Ms point ± 200 ° C, and T (20 + log 10 t) ≧ 100 at a temperature of 250 ° C or more and a time of 1 second or more.
It is characterized by performing tempering treatment so as to satisfy 00 (T: tempering temperature (K), t: tempering time (hour)) 1
A method for producing a high-strength PC rod wire having a strength of 500 MPa and excellent in delayed fracture resistance.
【００１２】ここで、ベーナイト比率は、Ｃ断面切断方
向のサンプルをＳＥＭまたは光学顕微鏡等により５００
０倍以下で観察し、単位面積当たりのベーナイト面積の
百分率と定義する。Here, the bainite ratio is 500 for a sample in the C-section cutting direction by SEM or an optical microscope.
Observed at 0 times or less, and defined as the percentage of bainite area per unit area.
【００１３】[0013]
【作用】本発明者は、耐遅れ破壊特性に優れた高張力Ｐ
Ｃ棒線とその製造方法の開発を進めた結果、鋼片から棒
線へ圧延する際の加熱温度及び仕上げ温度を制御し、イ
ンラインにてオーステンパー処理する事によりオーステ
ナイト粒を微細化した上、更にオーステナイト粒界に炭
化物の析出量が少ない下部ベーナイト組織の比率を多く
する事がＰＣ鋼棒の遅れ破壊特性改善に効果的である事
を見いだした。The present inventors have found that the high tensile strength P which is excellent in delayed fracture resistance.
As a result of advancing the development of C bar wire and its manufacturing method, the heating temperature and finishing temperature during rolling from the steel slab to the bar wire were controlled, and the austenite grains were refined by in-line austempering, Further, it has been found that increasing the ratio of the lower bainite structure in which the precipitation amount of carbide is small in the austenite grain boundary is effective in improving the delayed fracture property of the PC steel bar.
【００１４】そこでまず、ＰＣ棒線の耐遅れ破壊性を改
善するために必要なオーステナイト粒径及び下部ベーナ
イトの比率を検討した。Then, first, the austenite grain size and the ratio of lower bainite necessary for improving the delayed fracture resistance of PC rods were examined.
【００１５】例えば、０．３５％Ｃ＋２．０％Ｓｉ＋
０．８０％Ｍｎ＋０．０２０％Ｔｉ＋２０ｐｐｍＢ＋
０．０４５％Ａｌ組成の１２２角鋼片より圧延し、線径
７．０φの棒鋼線を製造するにあたり、その加熱温度及
び仕上げ温度を変え棒線のオーステナイト粒径を変化さ
せ、更に圧延終了後に３７０℃のソルトバスに浸漬する
時間をさまざまに変えて下部ベーナイトの比率を変化さ
せたＰＣ鋼線の耐遅れ破壊特性を調べた。つまり、図１
に示すように円周にノッチを設けた試験片１を作り、試
験片１のノッチ部を５０℃の２０％ＮＨ4 ＳＣＮ水溶液
中に浸漬し、試験片１に０．７σB の定引張荷重を負荷
して破断までの時間を測定し、耐遅れ破壊特性を評価し
た。For example, 0.35% C + 2.0% Si +
0.80% Mn + 0.020% Ti + 20ppmB +
In manufacturing a steel bar wire having a wire diameter of 7.0φ by rolling from a 122 square steel slab having a composition of 0.045% Al, the heating temperature and the finishing temperature are changed to change the austenite grain size of the bar wire, and further, after rolling, 370 The delayed fracture resistance characteristics of PC steel wire in which the ratio of the lower bainite was changed by changing the time of immersion in a salt bath at ℃ was investigated. That is, FIG.
As shown in Fig. 3, a test piece 1 having a notch on its circumference is made, and the notch part of the test piece 1 is immersed in a 20% NH 4 SCN aqueous solution at 50 ° C, and a constant tensile load of 0.7σ B is applied to the test piece 1. Was applied to measure the time until fracture, and evaluated the delayed fracture resistance.
【００１６】その結果を整理したのが図２である。オー
ステナイト粒度番号で１０番以上及び下部ベーナイトの
比率が４０％以上であれば、ＰＣ鋼線の遅れ破壊特性が
改善される事が判明した。特に、オーステナイト粒度番
号で１２番以上、下部ベーナイト比率で６０％以上の場
合に改善が著しく、この範囲内に制御する事が望まし
い。The results are summarized in FIG. It was found that when the austenite grain size number is 10 or more and the ratio of the lower bainite is 40% or more, the delayed fracture property of the PC steel wire is improved. In particular, when the austenite grain size number is 12 or more and the lower bainite ratio is 60% or more, the improvement is remarkable, and it is desirable to control within this range.
【００１７】次に、前述の組織を確保する圧延方法を検
討した。まず、オーステナイト粒径を１０番以上へ安定
的に制御する方法を検討した。従来の線材は、１２２角
の鋼片を１２５０℃程度に加熱し、仕上げミル直後の温
度が１１００℃程度で圧延され製造されている。しか
し、この方法では、得られる線材のオーステナイト粒度
番号は８〜１０番程度であり、それ以上のものを安定的
に製造する事は困難である。そこで、鋼片の加熱温度を
低める事により加熱炉内での鋼片のオーステナイト粒径
の粗大化を抑制し、しかもその後低温で圧延する事によ
りオーステナイト粒径の微細化を図る事とした。オース
テナイト粒径に及ぼす加熱温度と圧延仕上げ温度の影響
を検討し、整理したのが図３である。オーステナイト粒
度番号で１０番以上を確保する為には、加熱温度で１２
００℃以下、仕上げ温度で９５０℃以下とする事が必要
である。特に安定的に微細化する事を考えると、１１０
０℃以下の加熱温度及び８００℃以下の仕上げ温度が望
ましい。しかし、加熱温度９５０℃未満及び仕上げ温度
６００℃未満では熱間圧延の変形抵抗が急増し、熱間圧
延が困難となるのでこれを下限とした。Next, a rolling method for securing the above-mentioned structure was examined. First, a method for stably controlling the austenite grain size to 10 or more was examined. The conventional wire rod is manufactured by heating a 122-square steel piece to about 1250 ° C and rolling at a temperature of about 1100 ° C immediately after the finishing mill. However, according to this method, the austenite grain size number of the obtained wire is about 8 to 10, and it is difficult to stably produce more than that. Therefore, it was decided to lower the heating temperature of the steel slab to suppress coarsening of the austenite grain size of the steel slab in the heating furnace, and to further refine the austenite grain size by rolling at a low temperature thereafter. The effect of heating temperature and rolling finishing temperature on the austenite grain size was examined and arranged in FIG. To secure the austenite grain size number of 10 or more, the heating temperature is 12
It is necessary to set the temperature to 00 ° C or lower and the finishing temperature to 950 ° C or lower. Considering stable miniaturization, 110
A heating temperature of 0 ° C. or lower and a finishing temperature of 800 ° C. or lower are desirable. However, if the heating temperature is less than 950 ° C. and the finishing temperature is less than 600 ° C., the deformation resistance of hot rolling increases rapidly, and hot rolling becomes difficult, so this was made the lower limit.
【００１８】次に、圧延後の恒温変態条件を検討した結
果が図４である。Ｍｓ点より２００℃以上高い温度では
高温変態生成物を生成してしまい、下部ベーナイトを４
０％以上安定的に生成させ、強度１５００ＭＰａ以上の
鋼棒を製造する事が困難となる。また、Ｍｓ点より２０
０℃以上低い温度ではマルテンサイトの生成する量が増
大し、下部ベーナイトを４０％以上安定的に生成させる
事が困難となり、高い遅れ破壊特性を確保する事が困難
となるので、恒温変態温度をＭｓ点±２００℃の範囲に
規定した。Next, FIG. 4 shows the results of examining the isothermal transformation conditions after rolling. At a temperature higher than the Ms point by 200 ° C. or more, a high temperature transformation product is generated, and the lower bainite is converted into 4
It is difficult to stably produce 0% or more and to manufacture a steel bar having a strength of 1500 MPa or more. Also, 20 from the Ms point
At a temperature lower than 0 ° C., the amount of martensite generated increases, it becomes difficult to stably generate lower bainite by 40% or more, and it becomes difficult to secure a high delayed fracture property. It was defined in the range of Ms point ± 200 ° C.
【００１９】さらに、インラインで高周波コイル内を通
過させる、直接通電加熱する、またはソルトバス内を通
過させる事により焼戻し処理を実施すれば、工程省略及
び省エネルギーの観点からメリットが大きい。特に高周
波コイル内を通過させる急速加熱による焼戻し処理は、
炭化物を微細にオーステナイト粒内に析出させ、オース
テナイト粒界への炭化物の析出を抑制する事が可能とな
り、遅れ破壊特性を向上させる事となる。しかし、図５
に示す様に、２５０℃以上の温度及び１秒以上の時間で
Ｔ（２０＋ｌｏｇ10ｔ）≧１００００の条件を満足しな
ければ降伏比９０％以上を確保する事が困難となり、Ｊ
ＩＳＧ３１０９を満足しなくなる。Further, if the tempering process is carried out by in-line passage through a high-frequency coil, direct electric heating, or passage through a salt bath, there are great advantages from the viewpoint of process omission and energy saving. In particular, the tempering process by rapid heating that passes through the high-frequency coil is
It is possible to finely precipitate carbides in the austenite grains and suppress the precipitation of carbides in the austenite grain boundaries, thereby improving delayed fracture properties. However, FIG.
As shown in J, if the condition of T (20 + log 10 t) ≧ 10000 is not satisfied at the temperature of 250 ° C. or more and the time of 1 second or more, it becomes difficult to secure the yield ratio of 90% or more.
It no longer satisfies ISG3109.
【００２０】なお、圧延工程内でＰＣ鋼線特有の異径形
状へ加工する事により、大幅な省工程を図る事も出来
る。It should be noted that, by processing into a different diameter shape peculiar to PC steel wire in the rolling process, it is possible to achieve a great reduction in the process.
【００２１】次に成分限定理由を述べる。Next, the reasons for limiting the components will be described.
【００２２】《Ｃ》Ｃは下部ベーナイト棒線の高強度を
得るために０．１０％以上必要であるが、多すぎると靱
性とともに耐遅れ破壊特性を劣化させ、溶接性も劣化さ
せる為０．３９％以下とした。[C] C is required to be 0.10% or more in order to obtain the high strength of the lower bainite bar wire, but if it is too much, it deteriorates the toughness, delayed fracture resistance and weldability, so that it is less than 0.1%. It was set to 39% or less.
【００２３】《Ｓｉ》Ｓｉは鋼の脱酸および強度を高め
るのに必要な元素であるが、０．１％未満ではその効果
が得難い為０．１％以上とした。また３．０％を超える
とオーステナイト域加熱時に粒界に偏析する量が多くな
り過ぎ、著しく粒界を脆化させるとともに耐遅れ破壊特
性を劣化させる為３．０％以下とした。<< Si >> Si is an element necessary for deoxidizing the steel and enhancing the strength, but if it is less than 0.1%, its effect is difficult to obtain, so it is set to 0.1% or more. On the other hand, if it exceeds 3.0%, the amount segregated to the grain boundaries during heating in the austenite region becomes too large, which significantly embrittles the grain boundaries and deteriorates the delayed fracture resistance.
【００２４】《Ｍｎ》Ｍｎは鋼の脱酸および焼入れ性を
確保し、フェライト等の軟質組織の形成を抑制するのに
必要な元素であるが、０．２％未満ではその効果は得難
いので０．２％以上とした。また１．５％を超えるとオ
ーステナイト域加熱時に粒界に偏析する量が多くなり過
ぎ、著しく粒界を脆化させるとともに耐遅れ破壊特性を
劣化させる為１．５％以下とした。<< Mn >> Mn is an element necessary to secure deoxidation and hardenability of steel and suppress the formation of a soft structure such as ferrite, but if it is less than 0.2%, its effect is difficult to obtain, so 0 0.2% or more. On the other hand, if it exceeds 1.5%, the amount segregated at the grain boundaries during heating in the austenite region becomes too large, which significantly embrittles the grain boundaries and deteriorates the delayed fracture resistance, so the content was made 1.5% or less.
【００２５】《Ｎｉ》Ｎｉは、腐食環境中に素材の一部
のＦｅが溶解した後にＮｉが素材表面に残留する事によ
り素材表面をＮｉコーティングするのと同じ状況にな
り、それ以上の腐食進行を抑制する事により鋼材の耐食
性を向上させ、鋼材の耐遅れ破壊特性を向上させる元素
である。しかし、０．１％未満ではその効果が不十分で
ある為０．１％以上とした。又、２．０％を越えるとベ
ーナイト変態時間が長くなりすぎる上、腐食環境中に於
いて鋼材表面に腐食孔が著しく発生するようになり、む
しろ遅れ破壊特性が劣化するので２．０％以下とした。
ただし、Ｎｉは焼き入れ性を上げ、ベーナイト変態時間
を大幅に遅らせるので０．８％以下が望ましい。[Ni] Ni becomes the same situation as Ni coating on the surface of the material because Ni remains on the surface of the material after part of Fe of the material is dissolved in the corrosive environment, and further corrosion progresses. Is an element that improves the corrosion resistance of steel materials by suppressing the above, and improves the delayed fracture resistance of steel materials. However, if less than 0.1%, the effect is insufficient, so the content was made 0.1% or more. On the other hand, if it exceeds 2.0%, the bainite transformation time becomes too long, and in a corrosive environment, corrosion holes will remarkably occur on the surface of the steel material, and rather the delayed fracture property will deteriorate, so 2.0% or less. And
However, Ni increases the hardenability and significantly delays the bainite transformation time, so 0.8% or less is desirable.
【００２６】《Ｃｕ》Ｃｕは、腐食環境中に素材の一部
のＦｅが溶解した後にＣｕが素材表面に残留する事によ
り素材表面をＣｕコーティングするのと同じ状況にな
り、それ以上の腐食進行を抑制する事により鋼材の耐食
性を向上させ、鋼材の耐遅れ破壊特性を向上させる元素
である。しかし、０．１％未満ではその効果が不十分で
ある為０．１％以上とした。又、２．０％を越えると粒
界に偏析して粒界を脆化させ、鋼材の遅れ破壊特性が劣
化するので２．０％以下とした。ただし、Ｃｕは焼き入
れ性を上げ、ベーナイト変態時間を大幅に遅らせるので
１．０％以下が望ましい。<< Cu >> Cu is in the same condition as Cu coating on the surface of the material by leaving Cu on the surface of the material after part of Fe of the material is dissolved in a corrosive environment, and further corrosion progresses. Is an element that improves the corrosion resistance of steel materials by suppressing the above, and improves the delayed fracture resistance of steel materials. However, if less than 0.1%, the effect is insufficient, so the content was made 0.1% or more. On the other hand, if it exceeds 2.0%, it segregates at the grain boundaries to embrittle the grain boundaries and deteriorate the delayed fracture characteristics of the steel material. However, Cu increases the hardenability and significantly delays the bainite transformation time, so 1.0% or less is desirable.
【００２７】《Ａｌ》Ａｌは鋼の脱酸の安定化、均質化
及び細粒化を図るのに有効な元素であるが、０．００５
％未満ではその効果を得る事は出来ない。一方、０．１
％を越えて含有させてもその効果は飽和してしまい、ま
た介在物の増大によるきずが発生し、靱性を劣化させる
ため０．００５％以上０．１％以下とした。<< Al >> Al is an element effective for stabilizing, homogenizing, and refining the deoxidation of steel, but 0.005
If it is less than%, the effect cannot be obtained. On the other hand, 0.1
If it is contained in an amount exceeding 0.00%, the effect is saturated, and flaws are generated due to the increase of inclusions, and the toughness is deteriorated, so the content is made 0.005% to 0.1%.
【００２８】《Ｍｏ》Ｍｏは焼き入れ性を上げ、フェラ
イト等の軟質組織の形成を抑制するのに必要な元素であ
る上、腐食環境中にＭｏＯ-4イオンを形成し、素材表層
のＦｅと錯体を形成する事により耐食性の高いコーティ
ングを施し、腐食の進行を抑制する事により鋼材の耐食
性を向上させ、ＰＣ棒線の耐腐食疲労特性を向上させる
元素である。しかし、０．０１％未満ではその効果が不
十分である為０．０１％以上とした。又、２．０％を越
えるとその効果は飽和し、コストの上昇を招き実用的で
はないので２．０％以下とした。ただし、Ｍｏは焼き入
れ性を上げる元素である為、ベーナイトへの変態時間を
考えると０．５％以下が望ましい。<< Mo >> Mo is an element necessary for improving the hardenability and suppressing the formation of a soft structure such as ferrite. In addition, it forms MoO -4 ions in a corrosive environment, so that it becomes It is an element that forms a complex to form a coating having high corrosion resistance, and suppresses the progress of corrosion to improve the corrosion resistance of the steel material and to improve the corrosion fatigue resistance of the PC rod. However, if less than 0.01%, the effect is insufficient, so the content was made 0.01% or more. On the other hand, if it exceeds 2.0%, the effect is saturated and the cost increases, which is not practical. However, since Mo is an element that enhances hardenability, 0.5% or less is desirable considering the transformation time to bainite.
【００２９】《Ｗ》Ｗは焼き入れ性を上げ、フェライト
等の軟質組織の形成を抑制するのに必要な元素である
上、腐食環境中にＷＯ-4イオンを形成し、素材表層のＦ
ｅと錯体を形成する事により耐食性の高いコーテンィグ
を施し、腐食の進行を抑制する事により鋼材の耐食性を
向上させる。しかし、０．０１％未満ではその効果が不
十分である為０．０１％以上とした。又、２．０％を越
えるとその効果は飽和し、コストの上昇を招き実用的で
はないので２．０％以下とした。ただし、Ｗは焼き入れ
性を上げる元素である為、ベーナイトへの変態時間を考
えると０．５％以下が望ましい。<< W >> W is an element necessary for enhancing the hardenability and suppressing the formation of a soft structure such as ferrite. In addition, it forms WO -4 ions in a corrosive environment, and F on the surface layer of the material.
By forming a complex with e, coating with high corrosion resistance is applied, and the corrosion resistance of steel is improved by suppressing the progress of corrosion. However, if less than 0.01%, the effect is insufficient, so the content was made 0.01% or more. On the other hand, if it exceeds 2.0%, the effect is saturated and the cost increases, which is not practical. However, W is an element that enhances hardenability, so 0.5% or less is desirable in consideration of the transformation time to bainite.
【００３０】《Ｃｒ》Ｃｒは焼き入れ性を上げ、フェラ
イト等の軟質組織の形成を抑制するのに必要な元素であ
るが、効果を得る為には０．１％以上必要であり、多す
ぎると靱性を劣化させ、耐遅れ破壊特性の劣化を招く元
素であるため２．０％以下とした。<< Cr >> Cr is an element necessary for improving hardenability and suppressing the formation of a soft structure such as ferrite, but in order to obtain the effect, it is required to be 0.1% or more, which is too much. Since it is an element that deteriorates the toughness and deteriorates the delayed fracture resistance, the content is set to 2.0% or less.
【００３１】《Ｖ、Ｔｉ、Ｎｂ》Ｖ、Ｔｉ、Ｎｂは結晶
粒の微細化に寄与し、かつ水素との親和性に富み、鋼中
での水素の拡散・集積を抑制することにより耐遅れ破壊
特性向上に有効な元素であるため、Ｖ：０．０１％以
上、Ｔｉ：０．０１％以上、Ｎｂ：０．０１％以上必要
である。ただし多すぎるとその効果は飽和し、むしろ靱
性を劣化させ、耐遅れ破壊特性の劣化を招く元素である
ため、Ｖ：１．０％以下、Ｔｉ：０．５％以下、Ｎｂ：
０．５％以下とした。<< V, Ti, Nb >> V, Ti, and Nb contribute to the refinement of crystal grains and have a high affinity with hydrogen, and retardation of diffusion and accumulation of hydrogen in steel prevents delay. Since it is an element effective for improving the fracture characteristics, V: 0.01% or more, Ti: 0.01% or more, and Nb: 0.01% or more are required. However, if the amount is too large, the effect is saturated and rather the toughness is deteriorated and the delayed fracture resistance is deteriorated. Therefore, V: 1.0% or less, Ti: 0.5% or less, Nb:
It was set to 0.5% or less.
【００３２】《Ｂ》Ｂは鋼の焼入れ性を一段と向上させ
る作用があるので、特に太いＰＣ棒線でより高い強度が
要求される場合に添加するが、０．０００２％未満では
その効果を得る事は出来ない。一方、０．００５％を越
えて含有させてもその効果は飽和してしまい、しかも靱
性も劣化し、耐遅れ破壊特性が劣化する為０．０００２
％以上０．００５％以下とした。<< B >> Since B has the effect of further improving the hardenability of steel, it is added especially when higher strength is required for thick PC rods, but if it is less than 0.0002%, that effect is obtained. I can't do that. On the other hand, if the content exceeds 0.005%, the effect is saturated, the toughness also deteriorates, and the delayed fracture resistance deteriorates.
% And 0.005% or less.
【００３３】《Ｐ、Ｓ、Ｎ》Ｐ、Ｓ、Ｎに関して特に規
定はしないが、Ｐは凝固時にミクロ偏析し、さらにオー
ステナイト域加熱時に粒界に偏析し、粒界を脆化させる
とともに耐遅れ破壊特性を劣化させる元素であるため
０．０１５％以下が望ましい。Ｓは不可避的不純物であ
るが、オーステナイト域加熱時に粒界に偏析し、粒界を
脆化させるとともに耐遅れ破壊特性を劣化させる元素で
あるため０．０２％以下が望ましい。Ｎはオーステナイ
ト加熱時に粒界に偏析し、粒界を脆化させるとともに耐
遅れ破壊特性も劣化させる元素であるため０．０３％以
下が望ましい。<< P, S, N >> P, S, N are not particularly specified, but P segregates microscopically during solidification, and segregates to grain boundaries during heating in the austenite region, embrittles the grain boundaries and delays resistance. Since it is an element that deteriorates the fracture characteristics, 0.015% or less is desirable. Although S is an unavoidable impurity, it is an element that segregates at the grain boundaries during heating in the austenite region, embrittles the grain boundaries, and deteriorates the delayed fracture resistance, so 0.02% or less is desirable. N is an element that segregates at the grain boundaries during austenite heating, embrittles the grain boundaries, and deteriorates the delayed fracture resistance, so 0.03% or less is desirable.
【００３４】[0034]
【実施例】本発明の成分要件を満たす供試鋼の化学成分
を表１、表２に示す。この組成を有する１２２角の鋼片
の棒鋼を加熱炉で１２００〜９５０℃の範囲に加熱後、
７φ線材に仕上げ温度９５０〜６００℃の範囲で圧延
し、Ｍｓ点±２００℃温度範囲のソルトバスへ挿入して
オーステンパー処理を実施し、更に冷速１０℃／Ｓ以上
で冷却し焼き入れ後、高周波コイル内を通過させて２５
０〜４８０℃の範囲で焼戻し処理を実施し、強度１５０
０ＭＰａの７φＰＣ棒線を製造した。これらのＰＣ棒線
について、前述の遅れ破壊評価試験により耐遅れ破壊特
性を評価した。その結果を表３、表４に示す。また、比
較例のＰＣ棒線の遅れ破壊特性評価結果を表５、表６に
示した。[Examples] Tables 1 and 2 show the chemical composition of the sample steel satisfying the composition requirements of the present invention. After heating a steel bar of 122 square billets having this composition in the range of 1200 to 950 ° C. in a heating furnace,
7φ wire rod is rolled in the finishing temperature range of 950 to 600 ° C, inserted into a salt bath of Ms point ± 200 ° C temperature range, austempered, and further cooled at a cooling rate of 10 ° C / S or more and after quenching. , Passing through the high frequency coil 25
Tempering is performed in the range of 0 to 480 ° C and the strength is 150.
A 7MP PC rod of 0 MPa was manufactured. With respect to these PC rods, the delayed fracture resistance test was evaluated by the delayed fracture evaluation test described above. The results are shown in Tables 3 and 4. Tables 5 and 6 show the results of evaluating the delayed fracture characteristics of the PC bar wire of the comparative example.
【００３５】[0035]
【表１】 [Table 1]
【００３６】[0036]
【表２】 [Table 2]
【００３７】[0037]
【表３】 [Table 3]
【００３８】[0038]
【表４】 [Table 4]
【００３９】[0039]
【表５】 [Table 5]
【００４０】[0040]
【表６】 [Table 6]
【００４１】この表より、本発明例は比較例に比べて破
断時間が約２倍以上長く、遅れ破壊しにくい事が明らか
となった。From this table, it became clear that the breaking time of the present invention example is about twice as long as that of the comparative example, and delayed fracture is less likely to occur.
【００４２】[0042]
【発明の効果】本発明により１５００ＭＰａ級以上の引
張強度を有し、耐遅れ破壊特性の優れたＰＣ棒線が得ら
れる。これによってコンクリート構造物の寿命及び安全
性が向上する。According to the present invention, a PC bar wire having a tensile strength of 1500 MPa or more and excellent in delayed fracture resistance can be obtained. This improves the life and safety of the concrete structure.
【図１】ＰＣ遅れ破壊評価試験用試験片を示す図であ
る。FIG. 1 is a view showing a test piece for a PC delayed fracture evaluation test.
【図２】ＰＣ鋼線の組織とＰＣ鋼線の耐遅れ破壊特性と
の関係を示す図である。FIG. 2 is a diagram showing the relationship between the structure of PC steel wire and the delayed fracture resistance of PC steel wire.
【図３】ＰＣ鋼線の組織のオーステナイト粒度番号に及
ぼす加熱温度及び仕上げ温度の影響を示す図である。FIG. 3 is a diagram showing the influence of heating temperature and finishing temperature on the austenite grain size number of the structure of PC steel wire.
【図４】ＰＣ鋼線の組織の下部ベーナイト組織に及ぼす
ソルト温度の影響を示す図である。FIG. 4 is a view showing an influence of a salt temperature on a lower bainite structure of a PC steel wire structure.
【図５】ＰＣ鋼線のインライン焼戻し条件とＰＣ鋼線の
降伏比との関係を示す図である。FIG. 5 is a diagram showing a relationship between an in-line tempering condition of a PC steel wire and a yield ratio of the PC steel wire.
１ 試験片 1 test piece
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成５年５月２７日[Submission date] May 27, 1993
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】発明の名称[Name of item to be amended] Title of invention
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【発明の名称】 耐遅れ破壊特性に優れた高強度ＰＣ棒
線とその製造方法[Title of Invention] delayed high-strength PC bars and a manufacturing method thereof having excellent fracture characteristics
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】特許請求の範囲[Name of item to be amended] Claims
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【特許請求の範囲】[Claims]
【手続補正３】[Procedure 3]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】０００８[Correction target item name] 0008
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【０００８】 化学成分として、重量％で、Ｃ：０．
１０〜０．３９％、Ｓｉ：０．１０〜３．０％、Ｍｎ：
０．２〜１．５％、Ａｌ：０．００５〜０．１０％を含
有し、残部鉄及び不可避的不純物から成り、組織がオー
ステナイト粒度番号で１０番以上及び下部ベーナイトの
比率が４０％以上である事を特徴とする１５００ＭＰａ
以上の強度を有する耐遅れ破壊特性に優れた高強度ＰＣ
棒線。As a chemical component, C: 0.
10 to 0.39%, Si: 0.10 to 3.0%, Mn:
0.2 to 1.5%, Al: 0.005 to 0.10%, balance iron and unavoidable impurities, the structure is austenite grain size number 10 or more and lower bainite ratio is 40% or more. 1500 MPa characterized by being
High strength PC which is excellent in delayed fracture resistance having the above intensity
Bar line.
【手続補正４】[Procedure amendment 4]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】０００９[Correction target item name] 0009
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【０００９】 化学成分として、重量％で、Ｃ：０．
１０〜０．３９％、Ｓｉ：０．１０〜３．０％、Ｍｎ：
０．２〜１．５％、Ａｌ：０．００５〜０．１０％を含
有し、その他強化元素としてＣｒ：０．１〜２．０％、
Ｍｏ：０．０１〜２．０％、Ｖ：０．０１〜１．０％、
Ｗ：０．０１〜２．０％、Ｎｉ：０．１〜２．０％、Ｃ
ｕ：０．１〜２．０％、Ｔｉ：０．０１〜０．５％、Ｎ
ｂ：０．０１〜０．５％、Ｂ：０．０００２〜０．００
５％の１種類または２種類以上を含有し、残部鉄及び不
可避的不純物から成り、組織がオーステナイト粒度番号
で１０番以上及び下部ベーナイトの比率が４０％以上で
ある事を特徴とする１５００ＭＰａ以上の強度を有する
耐遅れ破壊特性に優れた高強度ＰＣ棒線。As a chemical component, C: 0.
10 to 0.39%, Si: 0.10 to 3.0%, Mn:
0.2 to 1.5%, Al: 0.005 to 0.10%, Cr: 0.1 to 2.0% as other strengthening element,
Mo: 0.01 to 2.0%, V: 0.01 to 1.0%,
W: 0.01 to 2.0%, Ni: 0.1 to 2.0%, C
u: 0.1 to 2.0%, Ti: 0.01 to 0.5%, N
b: 0.01 to 0.5%, B: 0.0002 to 0.00
1% or more of 5% is contained, the balance is iron and inevitable impurities, the structure is austenite grain size number 10 or more, and the ratio of lower bainite is 40% or more, 1500 MPa or more A high-strength PC bar wire with high strength and excellent delayed fracture resistance.
【手続補正５】[Procedure Amendment 5]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１０[Correction target item name] 0010
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１０】 前記またはの耐遅れ破壊特性に優
れた高強度ＰＣ棒線の製造方法において、前記成分を含
有する鋼片を加熱条件９５０℃以上１２００℃以下、仕
上げ温度６００℃以上９５０℃以下で棒線に圧延後、Ｍ
ｓ点±２００℃の範囲でオーステンパー処理する事を特
徴とする１５００ＭＰａ以上の強度を有する耐遅れ破壊
特性に優れた高強度ＰＣ棒線の製造方法。[0010] In the method of the or high-strength PC bars having excellent delayed fracture properties of the components below 1200 ° C. The heating conditions 950 ° C. or more steel strips containing, rods finishing temperature 600 ° C. or higher 950 ° C. or less After rolling to wire, M
A method for manufacturing a high-strength PC rod wire having strength of 1500 MPa or more and excellent in delayed fracture resistance, characterized by performing austempering at a s point of ± 200 ° C.
【手続補正６】[Procedure correction 6]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１１[Correction target item name] 0011
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１１】 前記またはの耐遅れ破壊特性に優
れた高強度ＰＣ棒線の製造方法において、前記成分を含
有する鋼片を加熱条件９５０℃以上１２００℃以下、仕
上げ温度６００℃以上９５０℃以下で棒線に圧延後、直
ちにＭｓ点±２００℃の範囲でオーステンパー処理し、
更に２５０℃以上の温度及び１秒以上の時間でＴ（２０
＋ｌｏｇ10ｔ）≧１００００（Ｔ：焼戻し温度（Ｋ）、
ｔ：焼戻し時間（時間））を満足する様に焼戻し処理す
る事を特徴とする１５００ＭＰａ以上の強度を有する耐
遅れ破壊特性に優れた高強度ＰＣ棒線の製造方法。[0011] bar in the manufacturing method of the or high-strength PC bars having excellent delayed fracture resistance of the steel strips containing the components heating condition 950 ° C. or higher 1200 ° C. or less, at a finishing temperature 600 ° C. or higher 950 ° C. or less Immediately after rolling into a wire, austempering at Ms point ± 200 ° C range,
Further, at a temperature of 250 ° C. or higher and a time of 1 second or longer, T (20
+ Log 10 t) ≧ 10000 (T: tempering temperature (K),
t: A method for producing a high-strength PC rod wire having strength of 1500 MPa or more and excellent in delayed fracture resistance, characterized by performing a tempering treatment so as to satisfy a tempering time (hour).
Claims (4)
０〜０．３９％、Ｓｉ：０．１０〜３．０％、Ｍｎ：
０．２〜１．５％、Ａｌ：０．００５〜０．１０％を含
有し、残部鉄及び不可避的不純物から成り、組織がオー
ステナイト粒度番号で１０番以上及び下部ベーナイトの
比率が４０％以上である事を特徴とする１５００ＭＰａ
の強度を有する耐遅れ破壊特性に優れた高強度ＰＣ棒
線。1. As a chemical component, C: 0.1% by weight,
0 to 0.39%, Si: 0.10 to 3.0%, Mn:
0.2 to 1.5%, Al: 0.005 to 0.10%, balance iron and unavoidable impurities, the structure is austenite grain size number 10 or more and lower bainite ratio is 40% or more. 1500 MPa characterized by being
High strength PC bar wire with excellent strength and delayed fracture resistance.
０〜０．３９％、Ｓｉ：０．１０〜３．０％、Ｍｎ：
０．２〜１．５％、Ａｌ：０．００５〜０．１０％を含
有し、その他強化元素としてＣｒ：０．１〜２．０％、
Ｍｏ：０．０１〜２．０％、Ｖ：０．０１〜１．０％、
Ｗ：０．０１〜２．０％、Ｎｉ：０．１〜２．０％、Ｃ
ｕ：０．１〜２．０％、Ｔｉ：０．０１〜０．５％、Ｎ
ｂ：０．０１〜０．５％、Ｂ：０．０００２〜０．００
５％の１種類または２種類以上を含有し、残部鉄及び不
可避的不純物から成り、組織がオーステナイト粒度番号
で１０番以上及び下部ベーナイトの比率が４０％以上で
ある事を特徴とする１５００ＭＰａの強度を有する耐遅
れ破壊特性に優れた高強度ＰＣ棒線。2. The chemical component, in% by weight, is C: 0.1.
0 to 0.39%, Si: 0.10 to 3.0%, Mn:
0.2 to 1.5%, Al: 0.005 to 0.10%, Cr: 0.1 to 2.0% as other strengthening element,
Mo: 0.01 to 2.0%, V: 0.01 to 1.0%,
W: 0.01 to 2.0%, Ni: 0.1 to 2.0%, C
u: 0.1 to 2.0%, Ti: 0.01 to 0.5%, N
b: 0.01 to 0.5%, B: 0.0002 to 0.00
Strength of 1500 MPa characterized by containing 5% of 1 type or 2 types or more, consisting of balance iron and unavoidable impurities, and having a structure of austenite grain size number of 10 or more and lower bainite ratio of 40% or more. High strength PC bar wire with excellent delayed fracture resistance.
の強度を有する耐遅れ破壊特性に優れた高強度ＰＣ棒線
の製造方法において、前記成分を含有する鋼片を加熱条
件９５０℃以上１２００℃以下、仕上げ温度６００℃以
上９５０℃以下で棒線に圧延後、Ｍｓ点±２００℃の範
囲でオーステンパー処理する事を特徴とする１５００Ｍ
Ｐａの強度を有する耐遅れ破壊特性に優れた高強度ＰＣ
棒線の製造方法。3. 1500 MPa according to claim 1 or 2.
In a method for producing a high-strength PC rod having excellent strength against delayed fracture, a steel slab containing the above components is formed into a rod under heating conditions of 950 ° C to 1200 ° C and finishing temperatures of 600 ° C to 950 ° C. 1500M characterized by austempering at Ms point ± 200 ° C after rolling
High strength PC with strength of Pa and excellent delayed fracture resistance
Manufacturing method of bar wire.
の強度を有する耐遅れ破壊特性に優れた高強度ＰＣ棒線
の製造方法において、前記成分を含有する鋼片を加熱条
件９５０℃以上１２００℃以下、仕上げ温度６００℃以
上９５０℃以下で棒線に圧延後、直ちにＭｓ点±２００
℃の範囲でオーステンパー処理し、更に２５０℃以上の
温度及び１秒以上の時間でＴ（２０＋ｌｏｇ10ｔ）≧１
００００（Ｔ：焼戻し温度（Ｋ）、ｔ：焼戻し時間（時
間））を満足する様に焼戻し処理する事を特徴とする１
５００ＭＰａの強度を有する耐遅れ破壊特性に優れた高
強度ＰＣ棒線の製造方法。4. 1500 MPa according to claim 1 or 2.
In a method for producing a high-strength PC rod having excellent strength against delayed fracture, a steel slab containing the above components is formed into a rod under heating conditions of 950 ° C to 1200 ° C and finishing temperatures of 600 ° C to 950 ° C. Immediately after rolling, Ms point ± 200
Austempering is performed in the range of ℃, and T (20 + log 10 t) ≧ 1 at a temperature of 250 ℃ or more and a time of 1 second or more.
Characteristic of performing tempering treatment so as to satisfy 0000 (T: tempering temperature (K), t: tempering time (hour)) 1
A method for producing a high-strength PC rod wire having a strength of 500 MPa and excellent in delayed fracture resistance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11115193A JPH06306543A (en) | 1993-04-15 | 1993-04-15 | High strength pc wire rod excellent in delayed fracture resistance and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11115193A JPH06306543A (en) | 1993-04-15 | 1993-04-15 | High strength pc wire rod excellent in delayed fracture resistance and its production |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06306543A true JPH06306543A (en) | 1994-11-01 |
Family
ID=14553758
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11115193A Withdrawn JPH06306543A (en) | 1993-04-15 | 1993-04-15 | High strength pc wire rod excellent in delayed fracture resistance and its production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06306543A (en) |
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007239051A (en) * | 2006-03-09 | 2007-09-20 | Kobe Steel Ltd | Ultrahigh strength steel with excellent workability and delayed fracture resistance, and its manufacturing method |
| JP2012088241A (en) * | 2010-10-21 | 2012-05-10 | Nippon Steel Corp | Delayed fracture characteristic evaluation method for pc steel |
| JP2013142684A (en) * | 2012-01-13 | 2013-07-22 | Neturen Co Ltd | Delayed fracture characteristics evaluation method of pc steel |
| JP2016008349A (en) * | 2014-06-26 | 2016-01-18 | 新日鐵住金株式会社 | High-strength steel material and production method thereof |
| WO2016052093A1 (en) * | 2014-09-30 | 2016-04-07 | 株式会社神戸製鋼所 | Steel for bolts, and bolt |
| KR20190078129A (en) * | 2017-12-26 | 2019-07-04 | 주식회사 포스코 | Steel wire rod for cold forging, processed good using the same, and methods for manufacturing thereof |
| KR20200025713A (en) * | 2018-08-31 | 2020-03-10 | 주식회사 포스코 | Steel wire rod for cold forging, processed good using the same, and methods for manufacturing thereof |
| WO2020093688A1 (en) * | 2018-11-08 | 2020-05-14 | 南京钢铁股份有限公司 | Weather-resistant bridge steel and smelting process |
| KR20200076540A (en) * | 2018-12-19 | 2020-06-29 | 주식회사 포스코 | Steel wire rod for cold forging with improved impact toughness, processed good using the same, and methods for manufacturing thereof |
| WO2021125555A1 (en) * | 2019-12-18 | 2021-06-24 | 주식회사 포스코 | Wire rod and component, for cold forging, each having excellent delayed fracture resistance characteristics, and manufacturing methods therefor |
| KR20210077529A (en) | 2019-12-17 | 2021-06-25 | 주식회사 포스코 | Wire rod for cold head quality steel with excellent resistance to hydrogen delayed fracture, and method for manufacturing thereof |
| CN113073258A (en) * | 2021-03-12 | 2021-07-06 | 中天钢铁集团有限公司 | High-temperature-resistant quenching chain steel wire rod suitable for continuous pass type induction heating furnace and manufacturing method |
| KR20220089179A (en) * | 2020-12-21 | 2022-06-28 | 주식회사 포스코 | Method for manufacturing a high strength wire rod |
| CN115216700A (en) * | 2022-08-01 | 2022-10-21 | 马鞍山钢铁股份有限公司 | 1700 MPa-level steel for fasteners and production method and heat treatment process thereof |
| CN115261724A (en) * | 2022-08-01 | 2022-11-01 | 马鞍山钢铁股份有限公司 | Steel for ultrahigh-strength and high-toughness fastener and production method and heat treatment process thereof |
| CN115612927A (en) * | 2022-09-27 | 2023-01-17 | 联峰钢铁（张家港）有限公司 | Vanadium-containing alloy tool steel and production process thereof |
-
1993
- 1993-04-15 JP JP11115193A patent/JPH06306543A/en not_active Withdrawn
Cited By (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007239051A (en) * | 2006-03-09 | 2007-09-20 | Kobe Steel Ltd | Ultrahigh strength steel with excellent workability and delayed fracture resistance, and its manufacturing method |
| JP2012088241A (en) * | 2010-10-21 | 2012-05-10 | Nippon Steel Corp | Delayed fracture characteristic evaluation method for pc steel |
| JP2013142684A (en) * | 2012-01-13 | 2013-07-22 | Neturen Co Ltd | Delayed fracture characteristics evaluation method of pc steel |
| JP2016008349A (en) * | 2014-06-26 | 2016-01-18 | 新日鐵住金株式会社 | High-strength steel material and production method thereof |
| WO2016052093A1 (en) * | 2014-09-30 | 2016-04-07 | 株式会社神戸製鋼所 | Steel for bolts, and bolt |
| JP2016069705A (en) * | 2014-09-30 | 2016-05-09 | 株式会社神戸製鋼所 | Steel for bolt and bolt |
| KR20190078129A (en) * | 2017-12-26 | 2019-07-04 | 주식회사 포스코 | Steel wire rod for cold forging, processed good using the same, and methods for manufacturing thereof |
| KR20200025713A (en) * | 2018-08-31 | 2020-03-10 | 주식회사 포스코 | Steel wire rod for cold forging, processed good using the same, and methods for manufacturing thereof |
| US11905571B2 (en) | 2018-08-31 | 2024-02-20 | Posco Co., Ltd | Wire rod for cold heading, processed product using same, and manufacturing methods therefor |
| WO2020093688A1 (en) * | 2018-11-08 | 2020-05-14 | 南京钢铁股份有限公司 | Weather-resistant bridge steel and smelting process |
| KR20200076540A (en) * | 2018-12-19 | 2020-06-29 | 주식회사 포스코 | Steel wire rod for cold forging with improved impact toughness, processed good using the same, and methods for manufacturing thereof |
| CN114787410A (en) * | 2019-12-17 | 2022-07-22 | 株式会社Posco | Wire rod for cold heading having excellent delayed fracture resistance characteristics, member and method for manufacturing same |
| WO2021125749A3 (en) * | 2019-12-17 | 2021-08-05 | 주식회사 포스코 | Wire rod for cold heading having excellent delayed fracture resistance characteristics, parts, and manufacturing method therefor |
| KR20210077529A (en) | 2019-12-17 | 2021-06-25 | 주식회사 포스코 | Wire rod for cold head quality steel with excellent resistance to hydrogen delayed fracture, and method for manufacturing thereof |
| CN114787410B (en) * | 2019-12-17 | 2023-09-19 | 株式会社Posco | Cold heading wire rod and part having excellent delayed fracture resistance characteristics and method for manufacturing the same |
| WO2021125555A1 (en) * | 2019-12-18 | 2021-06-24 | 주식회사 포스코 | Wire rod and component, for cold forging, each having excellent delayed fracture resistance characteristics, and manufacturing methods therefor |
| KR20220089179A (en) * | 2020-12-21 | 2022-06-28 | 주식회사 포스코 | Method for manufacturing a high strength wire rod |
| CN113073258A (en) * | 2021-03-12 | 2021-07-06 | 中天钢铁集团有限公司 | High-temperature-resistant quenching chain steel wire rod suitable for continuous pass type induction heating furnace and manufacturing method |
| CN115216700A (en) * | 2022-08-01 | 2022-10-21 | 马鞍山钢铁股份有限公司 | 1700 MPa-level steel for fasteners and production method and heat treatment process thereof |
| CN115261724A (en) * | 2022-08-01 | 2022-11-01 | 马鞍山钢铁股份有限公司 | Steel for ultrahigh-strength and high-toughness fastener and production method and heat treatment process thereof |
| CN115612927A (en) * | 2022-09-27 | 2023-01-17 | 联峰钢铁（张家港）有限公司 | Vanadium-containing alloy tool steel and production process thereof |
| CN115612927B (en) * | 2022-09-27 | 2023-07-14 | 联峰钢铁（张家港）有限公司 | Vanadium-containing alloy tool steel and production process thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6245271B2 (en) | Steel bar | |
| WO2011062012A1 (en) | Steel wire for low-temperature annealing and method for producing the same | |
| JP3898814B2 (en) | Continuous cast slab for high strength steel with excellent low temperature toughness and its manufacturing method, and high strength steel with excellent low temperature toughness | |
| EP3034643B1 (en) | Electric-resistance-welded steel pipe with excellent weld quality and method for producing same | |
| JP6212473B2 (en) | Rolled material for high-strength spring and high-strength spring wire using the same | |
| JP5846080B2 (en) | High-strength steel with excellent delayed fracture resistance | |
| JP2005290547A (en) | High carbon hot-rolled steel sheet having excellent ductility and stretch-flange formability, and production method therefor | |
| JP2007146284A (en) | High-strength steel excellent in delayed fracture resistance characteristic and metal bolt | |
| JPH06306543A (en) | High strength pc wire rod excellent in delayed fracture resistance and its production | |
| KR20210091755A (en) | Hot rolled steel strip and manufacturing method thereof | |
| JP2020504236A (en) | High-strength steel excellent in fracture initiation and propagation resistance at low temperature, and method for producing the same | |
| WO2015146173A1 (en) | High-carbon hot-rolled steel sheet and method for producing same | |
| WO2015146174A1 (en) | High-carbon hot-rolled steel sheet and method for producing same | |
| JP4507708B2 (en) | Low yield ratio high strength high toughness steel sheet manufacturing method | |
| JP5151693B2 (en) | Manufacturing method of high-strength steel | |
| JP5008879B2 (en) | High strength steel plate with excellent strength and low temperature toughness and method for producing high strength steel plate | |
| JPH06336648A (en) | High strength pc bar wire excellent in delayed fracture resistance and its production | |
| WO2011043287A1 (en) | Steel for linepipe having good strength and malleability, and method for producing the same | |
| JP6673320B2 (en) | Thick steel plate and method for manufacturing thick steel plate | |
| US5658402A (en) | High-carbon steel wire rod and wire excellent in drawability and methods of producing the same | |
| US5665182A (en) | High-carbon steel wire rod and wire excellent in drawability and methods of producing the same | |
| JPH11172374A (en) | Bent pipe with high strength and high toughness, and its production | |
| US5647918A (en) | Bainite wire rod and wire for drawing and methods of producing the same | |
| JP4265583B2 (en) | Cold-rolled steel sheet having excellent toughness after quenching and method for producing the same | |
| JP2006063425A (en) | Hot-rolled, non-heat treated steel bar and its manufacturing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20000704 |