JPS58174523A - Manufacture of very fine-grained high-strength hot-worked steel material - Google Patents
Manufacture of very fine-grained high-strength hot-worked steel materialInfo
- Publication number
- JPS58174523A JPS58174523A JP5564982A JP5564982A JPS58174523A JP S58174523 A JPS58174523 A JP S58174523A JP 5564982 A JP5564982 A JP 5564982A JP 5564982 A JP5564982 A JP 5564982A JP S58174523 A JPS58174523 A JP S58174523A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- cooling
- temperature range
- fine
- hot
- 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
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/002—Bainite
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/008—Martensite
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
本発明線熱延ま＼で極微細な７工２イト結晶組織管有す
る延性の優れた細粒組織鋼材の製造方法に関するもので
ある。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a fine-grained steel having excellent ductility and having an ultra-fine 7-item crystal structure tube by wire hot rolling.
ここで言う細粒７工２イト組織は大部分、通常７０〜８
０％以上が微細フェライト結晶粒よシ成り、所望の機械
的性質によって祉７エ２イト相以外に他の微＃Ｉな組織
１例えにパー２イト、マルテンサイト、残留オーステナ
イト等のうち一′：＋ｔたけ二つ以上を有しても良いし
、カーバイド中ナイト２イド等の析出物を有しても良い
。Most of the fine-grained 7-2ite structures mentioned here are usually 70 to 8
0% or more is composed of fine ferrite crystal grains, and depending on the desired mechanical properties, in addition to the ferrite phase, other fine structures such as peroxide, martensite, retained austenite, etc. : +t may have two or more, or may have precipitates such as nite 2 in carbide.
本発明で細粒フェライトと呼ぶ組織紘、粒の形の着しい
伸長を伴わず、はぼ等方的であり、また原則としていわ
ゆる大傾角粒界で囲まれた結晶粒からなる組織を指し、
亜結晶粒界（小領内粒界）は粒界として見なしていない
、ただし、このような粒の内部に多少の転位密度の増加
と亜粒界Ｏ形成はあシ得る。The structure called fine-grained ferrite in the present invention is almost isotropic without any elongation of the grain shape, and in principle refers to a structure consisting of crystal grains surrounded by so-called high-angle grain boundaries.
Subgrain boundaries (grain boundaries within small regions) are not regarded as grain boundaries; however, some increase in dislocation density and formation of subgrain O may occur inside such grains.
鋼０１ａ々の強化方法のうちで結晶粒の黴細化社強度と
共に靭性をも高くする唯一〇方法として知られてお９％
％に熱延壕まで使用される鉄鋼材料の材質向上を針る際
Ｋａ殆んどの場合に先ず考慮されねばならない重要な技
術である。従来の細粒化技術で工業的に達成されている
のは小さくて４〜６声ｇ度である。これは通常制御圧延
法と呼ばれる方法で行われておりｂ Ｎｂｌの合金元素
を含む鋼を比較的低温域で強い圧延を行う技術である。Among the methods for strengthening steel 01a, it is known as the only method to increase toughness as well as strength by refining the crystal grains.
Ka is an important technology that must be considered first in most cases when trying to improve the quality of steel materials used in hot rolling trenches. The particle size that has been achieved industrially using conventional refining techniques is as small as 4 to 6 g degrees. This is usually carried out by a method called controlled rolling, which is a technique in which steel containing the bNbl alloying element is subjected to strong rolling at a relatively low temperature.
この場合Ｎｂが圧延ま＼で同浴している必要がｓｌｈの
で、圧延前に例えばｌ、２００℃以上という高温でカロ
熱を竹ってＮｂｔ固溶させ、しかるＯちに仕上圧延は８
００℃以下とり低温−で行うので、鋼板の＋１１１ｊＬ
低下を待つため生産効率が著しく低下し。In this case, it is necessary for Nb to be in the same bath as before rolling, so for example, before rolling, heat is applied at a high temperature of 200°C or higher to dissolve Nbt as a solid solution, and then finish rolling is carried out at 8
Since it is carried out at a low temperature below 00℃, +111jL of steel plate
As we wait for the decline, production efficiency drops significantly.
また圧延時の変形抵抗が着しく高くなるため、圧姑機に
対する負荷が大であるなど工業的に欠点がある。この他
に低温域で加熱して圧延を行う方法、あるいは圧延後強
制冷却を行う方法など種々考案されているが、いずれも
上記粒径範囲内に貿っておシ１本発明で云う超微細粒（
３〜４Ｊ以下）を工業的に得るに至っていない。In addition, since the deformation resistance during rolling becomes relatively high, there are industrial disadvantages such as a heavy load on the compaction machine. In addition, various methods have been devised, such as heating and rolling in a low-temperature range, or forced cooling after rolling, but none of them can produce particles within the above-mentioned particle size range. grain(
3 to 4 J) has not yet been obtained industrially.
一方、超微細粒組織を実験的に得る方法が最近検討され
ている０例えは、ＮＩ鋼などで、変態点前後で数回縁り
返し焼鈍を行う方法などである６、シかしこのような熱
処理は、経済性から見て工業的に実施することは困難で
あることは明らかである。On the other hand, a method of experimentally obtaining an ultrafine grain structure has recently been studied.An example is a method of performing edge-reverse annealing several times before and after the transformation point for NI steel. It is clear that heat treatment is difficult to implement industrially from an economic point of view.
本発明は実際に工業的に得られたこのような画期的な超
細粒鋼に関するものであり、とくに特殊な合金元素を用
いず０を主成分とする亜共析鋼で、しかも熱間加工ま＼
で得られる鋼に関するものである。The present invention relates to such an epoch-making ultra-fine-grained steel that has actually been obtained industrially, and in particular is a hypo-eutectoid steel whose main component is zero without using any special alloying elements. Processing
This relates to steel obtained in
即ち１本発明Ｂ、ｃｓ％以下、０以外の合金含有ｊ１１
３％以下であって実質的にＮｂ、 Ｔａ、 ＭＯ，Ｗを
含有しない鋼を、ｋｆＬ’８変態点以上の温度から冷却
する過程において、熱間加工を行い、その終段において
（Ａｒ１＋５Ｑ℃） 〜（Ａｒ３＋１００℃）の温贋域
で１秒以内に１ノリまたは２ノ臂ス以上の合針減向率が
５０Ｘ以上最も望壇しくは７ＩＮ以上であるような圧下
を加えることを特徴とする極ｉｌＩ度域において、２０
℃／秒以上の冷却速ＪＩＦの強制冷却を行うことによｐ
％性性向上線かることができる。That is, 1 Invention B, cs% or less, alloy content other than 0 j11
In the process of cooling steel containing 3% or less of Nb, Ta, MO, and W from a temperature above the kfL'8 transformation point, hot working is performed, and at the final stage (Ar1 + 5Q ° C.) It is characterized by applying such a reduction that the rate of declination of the combined needles of 1 or 2 arms or more is 50X or more, most preferably 7IN or more, within 1 second in the temperature range of ~ (Ar3 + 100℃). In the polar ilI degree range, 20
By performing forced cooling at a cooling rate of JIF of ℃/sec or more, p
% sexual improvement line can be seen.
以下に本発明の限足塩由について説明する。The limitations of the present invention will be explained below.
本発明で銅の化学成分を規定した塩山は次の通りである
。The chemical components of copper specified in the present invention are as follows.
ａ ＜ ｏ、 ３ｘ ニ一般にＣＩ！ｉ１が大暑くなる
とフェライト鷲が減少し、パーライトが主体の鋼となる
。a < o, 3x d CI in general! When i1 gets very hot, the ferrite content decreases and the steel becomes pearlite-based.
しかし本発明鋼では同−Ｃ量でも通常の場合よｐはるか
にフェライト量を増すことができるので。However, in the steel of the present invention, even with the same -C content, the ferrite content can be increased much more than in the normal case.
０：０．３Ｘｔでは７工２イト主体の組織を得ることが
できるが、こ、れｔ超えるとノ臂ンライト等の量が多く
なジノエフイト主体の！ｌＩを祷ることは−しくなる。At 0:0.3Xt, you can get a structure that is mainly composed of 7x2 and 2xt, but if you exceed this, you can get a structure that is mainly composed of 7xx and 2xxt, but if you exceed this, there will be a large amount of armpit light, etc. Praying for lI becomes -.
その他の合金元素の合計３Ｘ以下二本発明鋼紘原則とし
て０以外の合金元素の有無に拘らず得られるが、熱間加
工の最適温度が７００〜９００℃の間であってしかもＡ
ｒ５ｉ態点に対し、Ａｒｌ＋５０〜人ｒ！＋１００℃の
間が望ましいという関係があるので、 Ａｒｓ変態点を
合金元素でｄＪ４節した方が望ましい場合が多い、しか
し合金元素の合計量が３Ｘを超えるとＡｒ３が低くなシ
すぎて細粒が得られにくくなる。In principle, the steel according to the invention can be obtained with or without alloying elements other than 0, but if the optimum temperature for hot working is between 700 and 900°C, and A
For r5i point, Arl+50 ~ person r! Since there is a relationship that a temperature between +100°C and dJ4 is desirable, it is often desirable to set the Ars transformation point at dJ4 by alloying elements. However, if the total amount of alloying elements exceeds 3X, Ar3 is too low and fine grains are formed. It becomes difficult to obtain.
Ｎｂｅ Ｔ”ｓ ＭＯ＊ Ｗ’を実質的に含有しないこ
と：Ｎｂ、 Ｔａ、 Ｍｏ、 ＷはいずれもＳ結晶を遅
らせる元素として知られている。本発明鋼では熱間加工
時には含まれてはならない。Nbe T"s MO* W' should not be substantially contained: Nb, Ta, Mo, and W are all known as elements that retard S crystallization. In the steel of the present invention, they must not be included during hot working. .
本発明鋼の終段の加工に至る工程にはとくに制限はない
、すなわち通常に浴製された溶鋼は連続鉤造によってス
ラブにされても良いし、造塊−分塊工ｓＫよってスラブ
にされても良い、スラブは高温のまｔＨ延工楊に持ち来
たされても良いし、一旦冷却したものを再加熱しても良
い。スラブの加熱。加工条件としてはスラブが本発明の
加工工程直前にそのオーステナイト粒径が小さｉ程良く
なるものが一般的に望ましいと言えるが、本発明の加工
工程以前の条件は通常のもので良いので制限は設けない
。There are no particular restrictions on the process leading to the final processing of the steel of the present invention; in other words, the molten steel normally made in a bath may be made into a slab by continuous hammering, or it may be made into a slab by an ingot-blowing process. The slab may be brought to a hot rolling mill, or it may be cooled and then reheated. Heating the slab. It can be said that it is generally desirable that the austenite grain size of the slab immediately before the processing step of the present invention be improved as the austenite grain size decreases, but the processing conditions before the processing step of the present invention may be normal conditions, so there are no restrictions. Not provided.
本発明の特徴は該鋼を通常の１１５ｇｇ点（鋼がオース
テナイトであるａｍ域から徐冷途中でフェライト変態を
開始する温ｆｔ−指し、以下単にＡｒＡと百９）とＡｒ
ｊ変態点（同様に徐冷途中でバーライ）ｆ態ｆ：開始す
る温度を指し、以下単にＡｒ１と言う）を基準として（
Ａｒ１＋５０℃）〜（Ａｒ１＋５０℃）の温度域におい
て、短時間内に大圧下を加えることである。The feature of the present invention is that the steel can be used at the normal 115gg point (refers to the temperature at which ferrite transformation starts in the middle of slow cooling from the am range where the steel is austenite, hereinafter simply referred to as ArA) and the Ar
j transformation point (similarly, during slow cooling) f state f: refers to the starting temperature, hereinafter simply referred to as Ar1)
The purpose is to apply a large pressure within a short period of time in a temperature range of (Ar1+50°C) to (Ar1+50°C).
本発明者等は従来研究の殆んどなされていなかった大圧
下加工の熱間加工組織に対する効果を詳細に研死し、従
来全く知られてい□、なかった新らし、１：
い知見を得ｆｃ、その結果を模式的゛一式鯖１図に示す
。The present inventors investigated in detail the effect of large reduction on the hot-worked structure, which had not been studied in the past, and obtained new knowledge that was completely unknown in the past. fc, and the results are schematically shown in Figure 1.
この図で減閣率５０％以下の領域については比較的よく
知られていたし、ｔた大圧下でも比較的為ｔｍ城ではオ
ーステナイトが動的丹結晶を起すことは最近知られてき
た。しかじＡｒＳ前後で、大圧下を加えると加工時に変
態が起ることが今回はじめて明らかになつ友、またこれ
と一部重複して７工２図に示したように７工２イト粒が
著しく細粒化されることを知見した０本発明の熱間加工
条件の範囲ｒｉ＊ｔ５Ａおよび第２図から明らかに示さ
れている。即ち、適切な温度域において減面率が５０％
を超えると動的変態が生じて、３〜４μ以下の平均フェ
ライト粒径が得られるようになるが、減面率をさらに増
すと細粒化りさらに著しくなり、７５％程度では恐らく
フェライトの動的再結晶も加わシ、２ｊＩまたはそれ以
下という超微細粒となり、これ以上では細粒化効果はや
＼飽和する。これから−減面率は少なくとも５０％以上
で望ましくは７５％以上が最適であることがわかる。In this figure, the area where the reduction rate is less than 50% is relatively well known, and it has recently been known that austenite causes dynamic red crystals even under relatively large pressures. This is the first time that it has become clear that transformation occurs during processing when a large reduction is applied before and after ArS.Also, partially overlapping this, as shown in Figure 7-2, the 7-2ite grains are significantly The range of hot working conditions ri*t5A of the present invention, which was found to result in grain refinement, is clearly shown from FIG. 2. In other words, the area reduction rate is 50% in an appropriate temperature range.
If it exceeds 75%, dynamic transformation will occur and an average ferrite grain size of 3 to 4μ or less will be obtained, but if the area reduction rate is further increased, the grains will become finer and even more significant, and at around 75%, the ferrite grain size will probably be reduced. With the addition of natural recrystallization, ultrafine grains of 2JI or less are obtained, and above this the grain refining effect is somewhat saturated. From this, it can be seen that the optimal area reduction rate is at least 50%, preferably 75% or more.
なお、この圧下はｌノｅスで加えるのが最もよいが、第
２図に示したように短時間で多ノぞスで加えた累積歪で
４ｈハぼこれに近い効果があるという知見を得た。この
短時間は通常の圧延においては１抄機度以内であればよ
いことも知見し良、従って上の圧下率は累積され九合針
の減面率で置き換えることができる。Although it is best to apply this reduction in one nozzle, as shown in Figure 2, we have found that cumulative strain applied over a short period of time with many nozzles can have almost the same effect over 4 hours. Obtained. It is also known that this short time may be within one machine degree in normal rolling, and therefore the above rolling reduction ratio can be accumulated and replaced by the area reduction ratio of a nine-gouge needle.
なお、このような短時間Ｏ累積圧下は第＊＊の土部に示
すように線材圧延の仕上段階、ホットストリップ圧延の
後半で実際に実現が可能である。Incidentally, such a short-time O cumulative reduction can actually be realized in the finishing stage of wire rod rolling or in the latter half of hot strip rolling, as shown in the part **.
上記の熱間加工は全体の加工の最＃！段に行われること
が望ましいが、場合により圧延材の形状調整のための少
量の熱間または冷間の変形を与えても大きくその特性を
損うものではない。The above hot processing is the highest of all processing! Although it is preferable to perform the deformation in stages, if necessary, a small amount of hot or cold deformation may be applied to adjust the shape of the rolled material without significantly impairing its properties.
加工後の粒成長を抑制するためには大なる冷却速度で冷
却する事が望ましい、減面率が十分に大きいときや加工
仕上温度が適正な温度域内で低温情のときは鋼材断面が
小さければ放冷しても一粒が倚られるので特に限定する
必要はないが、減面率が下限に近いときや、製品鋼材断
面が大なる場合、ま念仕上濃度の高い場合祉加逮冷却が
必要であり、その下限は第３図に示すように２０ Ｃ／
ｓｅｃとなる。冷却速度の上限を限定する理由は無いが
、冷速か大きくて、少しでも未変態オーステナイトが残
存する場合はその部分が硬い第二相となシ。In order to suppress grain growth after processing, it is desirable to cool at a high cooling rate.When the area reduction rate is sufficiently large or when the finishing temperature is within the appropriate temperature range and the temperature is low, it is preferable to cool the steel material with a small cross section. Even if left to cool, each grain will be crushed, so there is no need to limit it in particular, but additional cooling is necessary when the area reduction rate is close to the lower limit, when the cross section of the product steel is large, or when the finish concentration is high. , and its lower limit is 20 C/ as shown in Figure 3.
sec. There is no reason to limit the upper limit of the cooling rate, but if the cooling rate is large and even a small amount of untransformed austenite remains, that part will become a hard second phase.
さらに強ｆ：を向上する効果がある。このように目的に
よっては加速冷却で材質、とくに強［を向上することが
できる。加速冷却を行なう温度域については、フェライ
トの粒成長、あるい祉圧処時に変態しなかった部分が冷
却中にフェライトまたはバーライ）Ｋ変態する６００℃
以上の温度域を含むべきであるのは当然である。Furthermore, there is an effect of improving the strong f:. In this way, depending on the purpose, accelerated cooling can improve material quality, especially strength. The temperature range for accelerated cooling is 600°C, where the grain growth of ferrite or the part that did not transform during the pressure treatment transforms into ferrite or barley during cooling.
It is natural that the above temperature range should be included.
本発明鋼は棟々の熱間加工法で提供できる。たとえは厚
板圧延、ホットストリップ圧延、線材圧延などであシ、
熱間押出おるいは熱間鍛造などの圧延以外の加工法でも
可能である。The steel of the present invention can be provided by various hot working methods. Examples include thick plate rolling, hot strip rolling, wire rod rolling, etc.
Hot extrusion or hot forging is also possible using processing methods other than rolling.
次に本発明の効果について述べる。Next, the effects of the present invention will be described.
前述のように細粒化すると強度靭性が向上することはよ
く知られているが、これまで４μ以下という１ｈ＃１粒
でその効果ｔ−ｉｘべた例はない、第４図社本発明で得
られ几細粒鋼（黒丸）のデータを従来鋼のデータととも
に示したものである。従来のデータ（白丸）はいわゆる
Ｐｅｔｃｌ＋の関係式によりよく整理できるが、本発明
による鋼はこの延長線からさらに向−トする傾向を示し
ている。ｔた、第５図は本発明鋼の延性を強度に対して
示したもので本発明鋼は従来鋼と同一強度レベルでより
高い延性が得られることがわかる。そのほかに％２〜３
μ以下の超細粒鋼では６００℃以上て著しく延性が向上
する超塑性現象を示すなどの％像のある特性を示す。As mentioned above, it is well known that strength and toughness improve with grain refinement, but so far there has been no example of a 1h #1 grain of 4 μ or less achieving the same T-ix effect. The data for fine-grained steel (black circles) are shown together with the data for conventional steel. Although the conventional data (white circles) can be well organized by the so-called Petcl+ relational expression, the steel according to the present invention shows a tendency to move further away from this extension line. Furthermore, FIG. 5 shows the ductility of the steel of the present invention relative to its strength, and it can be seen that the steel of the present invention has higher ductility than the conventional steel at the same strength level. Besides that,%2~3
Ultrafine-grained steel of μ or less exhibits certain characteristics such as a superplastic phenomenon in which ductility significantly increases at temperatures above 600°C.
このように本発明鋼では従来鋼をはるかに上回る特性を
示すので本発明の効果はきわめて莫大で、非常に低コス
トで合金元素等を添加せずに高品質の高張力鋼環を容易
に製造できるのである。In this way, the steel of the present invention exhibits properties that far exceed those of conventional steel, so the effects of the present invention are extremely large, and high-quality, high-strength steel rings can be easily manufactured at extremely low cost without adding alloying elements. It can be done.
実施例１
第１表に示す転炉浴製鋼■、■を２００−のスラブに連
続鋳造し、１１００℃に加熱後ホットストリップミルで
圧延して５−厚の鋼板とした。Example 1 Converter bath steel products (1) and (2) shown in Table 1 were continuously cast into 200-thick slabs, heated to 1100°C, and then rolled in a hot strip mill to form 5-thick steel plates.
粗圧延では２００■スラブ箸５０■まで７パスで圧延し
、仕上温度は９００〜１０００℃であった。In the rough rolling, the slab was rolled in 7 passes to a 200 mm slab with a thickness of 50 mm, and the finishing temperature was 900 to 1000°C.
仕上圧延のノゼススケジュールを第２表に示す。Table 2 shows the finish rolling noses schedule.
ムは本１１１１によるもので、１秒以内に行われる６゜
６書紐のノ臂ヌで合計ｓ８％の圧下を行つ九場合である
。Ｂｄ比軟Ｏ過常の圧延の例で、最終２圧下Ｏ圧下は会
計２７９６である。The example is based on Book 1111, and is a case of 9 cases in which a total reduction of s8% is performed with the elbow of a 6°6 writing string performed within 1 second. In the example of rolling with excessive Bd ratio and soft O, the final 2 O reduction is 2796.
以上の圧延条件の組合せと圧延された鋼板の機械的性質
を第３１！ｉＫ示す、なお本発明の仕上圧延ａｍ域ａｊ
ｌｌｌ１表の変態温度から計算すると、鋼■嬬６８０〜
８７０℃、鋼■で６６０〜８９０℃でＴｏｈ、試１３，
６．ｌｏｔ除いては圧延後の冷却は、ランアウトテーブ
ル上でスジレイ冷却で行い、２０ｑｃ／秒Ｏ本発明冷却
速度範囲内で行った。The 31st combination of the above rolling conditions and the mechanical properties of the rolled steel plate! Indicated by iK, finish rolling am area aj of the present invention
Calculating from the transformation temperature in table lll1, the steel is 680 ~
870℃, Toh at 660-890℃ with steel ■, test 13,
6. Cooling after rolling was carried out by streak cooling on a run-out table, except for the lot, and was carried out at a cooling rate of 20 qc/sec O within the cooling rate range of the present invention.
機軸的性質から本発明の効釆嬬明らかで６０１＃／−以
上の＊ｍを持ち、２０％以上Ｏすぐれ九嬌Ｉｋを有して
いる。The effectiveness of the present invention is clear from the mechanical properties, having *m of 601 #/- or more, and 9 Ik of 20% or more.
１１１ｍ１Ｋその組織写真の例（賦香４）を示すが。111m1K An example of a tissue photograph (Fuika 4) is shown below.
２〜＠１ｉｔ）４粒の等軸フェライト粒で殆んど占めら
れておル、前述の本発明鋼の典臘的な特徴を示、１：１
１：：・
している。2~@1it) It is mostly occupied by 4 equiaxed ferrite grains, exhibiting the typical characteristics of the steel of the present invention mentioned above, 1:1
1::・ I am doing it.
一方、比較材Ｏ賦香５は通常の高温での仕上であって急
冷の結果強度が上昇するが延性は不要であゐ、この組織
は第７ＥＫ示すようＫ ３０ Ｘ１１ｍ！焼きが入った
組織となっており、フェライトも。On the other hand, Comparative material O flavored 5 is finished at a normal high temperature and its strength increases as a result of rapid cooling, but ductility is not required, and this structure is K 30 x 11 m! as shown in No. 7 EK! It has a tempered structure and also contains ferrite.
針状となっておｐ１急冷途中で東部し大ことを示す、ｔ
た賦香６社圧延ａｔが本発−Ｏ範−よ避低い場合で、フ
ェライト粒径が十分細＜ｔ％Ａため強度がそれほど上昇
しない、賦香７およびｌｉｄ圧下率が小さい場合で、こ
Ｏ場合フエテイ）Ｉｎ急冷でかなル細か＜ａｎ、急冷ｔ
）８２１１ｍが多（１４丸め強度がチ少上昇するが１本
発明鋼に昧及ばない、仁の場合、第２相（〕〕臂−ツイ
トベイナイ））の比率がかな）大きく、ζＯ良め延性が
十分で妹ない。It becomes needle-shaped and reaches the eastern part during the rapid cooling of P1, indicating a major problem.
In this case, the rolling at of the 6 companies is lower than the original -O range, the ferrite grain size is sufficiently fine <t%A, so the strength does not increase much, and the 7 and lid rolling reduction ratios are small. O case) In quenching, kana le fine <an, quenching t
) 8211m is high (14 The rounding strength increases slightly, but it is not as good as the steel of the present invention. In the case of steel, the ratio of the second phase (〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕〕 That's enough and I don't have a sister.
以上から本発＠Ｏ効果が顕著なこと一―ｈかである。From the above, it is clear that the original @O effect is remarkable.
ａｎ表 供試鋼の化学虞分鑑成と 変態温度 １１２１１１ 仕上ノ臂ススケシ島−ルAn table: Chemical risk analysis of test steel Metamorphosis temperature 112111 Finishing Arm Susukeshi Island
第１図は０． Ｉ Ｓ Ｏ−Ｉ Ｍｎ鋼の熱間加工時Ｏ
ｊ量。
温度と加工璽發のｌｌｌ１級の関係を模式的に示した図
（熱間加工Ｉｌｌちに急冷し九組織で調査シ＊もの）、
第ｘｌｌｌは６．１５０− Ｉ Ｍｆｉ鋼の熱間加工時
の歪量とフェライト粒後の関係を示す園。
ｌｌ３１１１社加工終了螢の冷速と７工ライト粒甑０関
係を示す図。
第４図はＯｓ １−０ｍ １ ！Ｉ ’！、’； ０−
Ｏｓ ５〜ｌｅ ５ Ｍ＊鋼のフェライト結晶粒度と
降伏応力、＠性ＯＩＩ係を示す図。
第ｓｌＩは本尭―鋼と従来鋼の強度−延性バランスの比
較を示す図。
ＩＩ６図は本ｌｌ明鋼Ｏ党学類黴鏡による金属組織を示
す写真。
第７図は本ｌｉ＠より仕上１１ｆが高い比較鋼の党学馴
黴鏡による金属組織を示す写真である。
代通人 弁理士 秋 沢 政 党
他２４
− しパース圧延
□ 漣！売怒延（後段３）ぐス）
□ 系泉主才（ブレツク三）の
短蒔向（１利Ｖの累Ｉ霞威面中（％ク
ヂ豆日晋間（１才４つの甲積Ｌ
め３１
猟５図
ＴＳ（を愉屓ジ
活６図、
毛７図
牛
特許庁長官 殿
１．事件の表示
特願昭５７−第５５６４９ 号
２、発明の名称
３、補正をする者
事件との関係 出 願 人
住所（居所）東京都千代田区大手町２丁目６番３号氏名
（名称） （６６５）新日本製鐵株式会社４、代 理
人
居 所 東京都中央区日本橋兜町１２番１号大洋ビル７
、補正の対象 明細書（発明の詳細な説明）８、補正の
内容 別紙の通り
１、 明細書牙４頁下から５行目「０３％以下」を「Ｃ
０３％以下」と訂正する。
２、 回生５頁下から４行目「パンライト」を「パーラ
イト」と訂正する。
１Figure 1 shows 0. I SO-I O during hot working of Mn steel
j amount. A diagram schematically showing the relationship between temperature and processed grain in 1st grade (hot processed and then rapidly cooled and investigated using 9 structures),
No. xlll shows the relationship between the amount of strain during hot working of 6.150-I Mfi steel and the ferrite grain size. A diagram showing the relationship between the cooling speed of fireflies processed by ll3111 and 7-process light grain koshi 0. Figure 4 shows Os 1-0m 1! I'! ,'; 0-
A diagram showing the ferrite grain size, yield stress, and @OII ratio of Os 5 to le 5 M* steel. No. slI is a diagram showing a comparison of the strength-ductility balance between Hontaka steel and conventional steel. Figure II6 is a photograph showing the metallographic structure taken from the book Ill. FIG. 7 is a photograph showing the metallographic structure of a comparison steel with a higher finish of 11f than that of the real steel, taken by a metallurgical microscope. Agent Patent Attorney Aki Sawa Masa Party and 24 others - Perth Rolling □ Ren! Selling extension (second half 3) □ Kei spring master (bretsuku 3) short maki direction (1 profit V cumulative I Kawei side middle (% Kujizu day Shinma) (1 year old 4 Koseki L me 31 Hunting 5 TS (Enjoying TS 6, Ma 7 Cattle Commissioner of the Patent Office) 1. Indication of the case Patent Application No. 55649/1982 2. Name of the invention 3. Person making the amendment Relationship with the case Applicant Address: 2-6-3 Otemachi, Chiyoda-ku, Tokyo Name: (665) Nippon Steel Corporation 4, Agent
Location: Taiyo Building 7, 12-1 Nihonbashi Kabutocho, Chuo-ku, Tokyo
, Target of amendment: Description (detailed description of the invention) 8, Contents of amendment: As shown in Attachment 1, ``03% or less'' in the 5th line from the bottom of page 4 of the specification is changed to ``C
03% or less.'' 2. In the fourth line from the bottom of page 5 of the regeneration, "Panlite" is corrected to "Pearlite." 1
Claims (1)
おいて熱間加工を行い、その終段において（Ａｒｌ＋５
０℃） 〜（Ａｒｌ＋５０℃℃）の温度域で１秒以内に
１回ｔたは２＠以上の合計減肉率が５０Ｘ以上で・ある
ような加工を加えることを特徴とする。極細粒高強度熱
間加工鋼材の製造法。 （２）熱間加工終了後冷却過程の６００℃以上Ｏ高温域
を含む温度域において２０℃／秒以上の冷却速度の強制
冷却を行う特許請求の範囲第（１）項記載の方法。 （３）（λｒ１＋！＄０℃）〜（ムｒｓ ＋ ｔ ｏ
ｏ℃）の温度域で１秒以内に置針減面率が７６Ｎ以上の
１ノ臂スまたは２ノ（ス以上の加工を加える特許１ｌｌ
Ｉｌ求の範囲＠ （１）項記載の方法。 （４）（ムｒｌ ＋ ５０℃） 〜（Ａｒｌ＋５０℃）
のＩｌｆ域で１秒以円に置針減面率が７５Ｎ以上の１ノ
臂スを良は２／ｌス以上の加工を加え、さらに加工終了
Ｗｋの冷却過程の６００℃以上の高温域を含む温度域に
おいて２０℃／秒以上の冷却適度の強制冷却を行う特許
請求の範ｉ！！８第（１）項記載の方法。[Claims] Hot working is carried out in step b, in which the steel is cooled from a temperature above the A(L transformation point), and in the final stage, it is
It is characterized by applying processing such that the total thickness reduction rate is 50X or more at 1 time or 2@ or more within 1 second in the temperature range from 0°C to (Arl + 50°C). A manufacturing method for ultra-fine-grained, high-strength hot-worked steel. (2) The method according to claim (1), wherein forced cooling is performed at a cooling rate of 20° C./sec or more in a temperature range including a high temperature range of 600° C. or higher during the cooling process after the completion of hot working. (3) (λr1+!$0℃)～(ms + to
Patent 1ll that applies processing of 1 or 2 holes or more with a needle placement area reduction rate of 76N or more within 1 second in the temperature range of 0°C)
Scope of Il search @ method described in section (1). (4) (Mrl + 50℃) ~ (Arl + 50℃)
In the Ilf range of 1 second or more, one arm with a needle placement area reduction rate of 75N or more is processed at a rate of 2/l or more, and it also includes a high temperature range of 600°C or more during the cooling process at the end of processing Wk. Claim i! Moderate forced cooling of 20°C/sec or more in a temperature range! ! 8. The method described in paragraph (1).
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5564982A JPS58174523A (en) | 1982-04-03 | 1982-04-03 | Manufacture of very fine-grained high-strength hot-worked steel material |
| US06/481,453 US4466842A (en) | 1982-04-03 | 1983-04-01 | Ferritic steel having ultra-fine grains and a method for producing the same |
| DE3312257A DE3312257A1 (en) | 1982-04-03 | 1983-04-05 | FERRITIC STEEL WITH ULTRAFINE GRAIN AND METHOD FOR THE PRODUCTION THEREOF |
| FR8305500A FR2524493B1 (en) | 1982-04-03 | 1983-04-05 | FERRITIC STEEL WITH ULTRA-FINE GRAINS AND PROCESS FOR PRODUCING THE SAME |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5564982A JPS58174523A (en) | 1982-04-03 | 1982-04-03 | Manufacture of very fine-grained high-strength hot-worked steel material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58174523A true JPS58174523A (en) | 1983-10-13 |
| JPS627247B2 JPS627247B2 (en) | 1987-02-16 |
Family
ID=13004669
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5564982A Granted JPS58174523A (en) | 1982-04-03 | 1982-04-03 | Manufacture of very fine-grained high-strength hot-worked steel material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58174523A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59107023A (en) * | 1982-12-09 | 1984-06-21 | Nippon Steel Corp | Manufacture of hyperfine-grained hot-rolled steel plate |
| EP1136575A1 (en) * | 1999-08-10 | 2001-09-26 | Nkk Corporation | Method of producing cold rolled steel sheet |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4552731B2 (en) * | 2005-03-30 | 2010-09-29 | Ｊｆｅスチール株式会社 | Hot rolling method for steel strip |
| JP5646261B2 (en) | 2010-09-22 | 2014-12-24 | 三菱日立製鉄機械株式会社 | Hot strip strip cooling system |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54143717A (en) * | 1978-05-01 | 1979-11-09 | Kawasaki Steel Co | Continuous heat treatment of high carbon steel for high processed cold drawing |
| JPS5672127A (en) * | 1979-11-17 | 1981-06-16 | Nippon Steel Corp | Manufacture of low yield ratio complex structure high tension steel having excellent ductility |
| JPS5681620A (en) * | 1979-12-05 | 1981-07-03 | Nippon Steel Corp | Production of tin base low yield ratio composite structure high tensile steel plate |
-
1982
- 1982-04-03 JP JP5564982A patent/JPS58174523A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54143717A (en) * | 1978-05-01 | 1979-11-09 | Kawasaki Steel Co | Continuous heat treatment of high carbon steel for high processed cold drawing |
| JPS5672127A (en) * | 1979-11-17 | 1981-06-16 | Nippon Steel Corp | Manufacture of low yield ratio complex structure high tension steel having excellent ductility |
| JPS5681620A (en) * | 1979-12-05 | 1981-07-03 | Nippon Steel Corp | Production of tin base low yield ratio composite structure high tensile steel plate |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59107023A (en) * | 1982-12-09 | 1984-06-21 | Nippon Steel Corp | Manufacture of hyperfine-grained hot-rolled steel plate |
| JPS625212B2 (en) * | 1982-12-09 | 1987-02-03 | Nippon Steel Corp | |
| EP1136575A1 (en) * | 1999-08-10 | 2001-09-26 | Nkk Corporation | Method of producing cold rolled steel sheet |
| EP1136575A4 (en) * | 1999-08-10 | 2008-04-23 | Jfe Steel Corp | Method of producing cold rolled steel sheet |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS627247B2 (en) | 1987-02-16 |
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