JPH0693340A - Method and equipment for manufacturing high strength galvannealed steel sheet having stretch flanging formability - Google Patents
Method and equipment for manufacturing high strength galvannealed steel sheet having stretch flanging formabilityInfo
- Publication number
- JPH0693340A JPH0693340A JP27241892A JP27241892A JPH0693340A JP H0693340 A JPH0693340 A JP H0693340A JP 27241892 A JP27241892 A JP 27241892A JP 27241892 A JP27241892 A JP 27241892A JP H0693340 A JPH0693340 A JP H0693340A
- Authority
- JP
- Japan
- Prior art keywords
- steel sheet
- hot
- temperature
- dip galvanizing
- point
- 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- Withdrawn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、冷延鋼板を用いて、連
続焼鈍溶融亜鉛めっきラインでの熱履歴により金属組織
を制御することにより、優れた加工性、特に伸びフラン
ジ性の優れた高強度溶融亜鉛めっき鋼板を製造する製造
方法とその設備に関するものである。BACKGROUND OF THE INVENTION The present invention uses cold-rolled steel sheets to control the metal structure by the heat history in a continuous annealing hot-dip galvanizing line to obtain excellent workability, especially high stretch flangeability. The present invention relates to a manufacturing method and equipment for manufacturing a high-strength galvanized steel sheet.
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】近年、
自動車等の補強部材や足回り部材の軽量化及び防錆性能
の向上という観点から、強加工と高強度を有する溶融亜
鉛めっき鋼板のニーズが強い。2. Description of the Related Art In recent years,
There is a strong need for hot-dip galvanized steel sheets that have strong working and high strength from the viewpoint of reducing the weight of reinforcing members and underbody members of automobiles and improving rust prevention performance.
【０００３】従来、この溶融亜鉛めっき鋼板は、図１に
示す如く、均熱−冷却−溶融亜鉛めっき−合金化加熱か
らなるプロセスで製造されているが、このめっきライン
の熱処理では、最も優れた機械的特性値やλ値を示す焼
戻しマルテンサイト組織鋼は容易には製造できない。Conventionally, this hot-dip galvanized steel sheet is manufactured by a process of soaking, cooling, hot-dip galvanizing, and alloying heating, as shown in FIG. 1. The heat treatment of this galvanizing line is the most excellent. Tempered martensitic steels exhibiting mechanical property values and λ values cannot be easily manufactured.
【０００４】たとえ、この従来の連続焼鈍溶融亜鉛めっ
き設備において、均熱加熱後の強冷却により鋼板をＭs
点以下の温度に下げてマルテンサイトを生成させて、そ
の後、焼戻すことを試みたとしても、めっき浴槽(ポッ
ト)前の鋼板の温度が低いために亜鉛めっきがされ難
く、加工性の優れた溶融亜鉛めっき鋼板を得ることはで
きない。Even in this conventional continuous annealing hot dip galvanizing equipment, the steel sheet is subjected to Ms by strong cooling after soaking and heating.
Even if it is attempted to reduce the temperature below the point to generate martensite and then temper it, the temperature of the steel sheet before the plating bath (pot) is low and galvanization is difficult, resulting in excellent workability. It is not possible to obtain hot-dip galvanized steel sheets.
【０００５】従来、加工性の優れた高強度溶融亜鉛めっ
き鋼板については、めっき前の均熱温度や冷却速度を規
定している例もあるが、必ずしも十分な加工性が得られ
ていない。Conventionally, there are some examples of high strength hot-dip galvanized steel sheets having excellent workability, in which the soaking temperature and cooling rate before plating are regulated, but sufficient workability is not always obtained.
【０００６】例えば、伸びフランジ性の優れた高強度鋼
板については、変態組織強化タイプのフェライト−ベイ
ナイト組織鋼が既に開発されている。しかし、変態組織
強化材を溶融亜鉛めっきすると、めっき化による熱履歴
を被るため、局部延性の低下が著しくなり、加工性が劣
化するのが一般的である。[0006] For example, as a high strength steel sheet having excellent stretch flangeability, a transformation structure strengthening type ferrite-bainite structure steel has been already developed. However, when hot-dip galvanizing the transformation structure reinforcing material is subject to heat history due to plating, the local ductility is remarkably reduced and the workability is generally deteriorated.
【０００７】このように、従来の溶融亜鉛めっきライン
で優れた伸びフランジ性(λ値)を得ることは容易ではな
かった。As described above, it was not easy to obtain excellent stretch flangeability (λ value) in the conventional hot dip galvanizing line.
【０００８】本発明は、かゝる状況のもとで、連続焼鈍
溶融亜鉛めっきラインにて、優れた加工性、特に伸びフ
ランジ性の優れた高強度溶融亜鉛めっき鋼板を製造する
技術を提供することを目的とするものである。Under such circumstances, the present invention provides a technique for producing a high-strength hot-dip galvanized steel sheet having excellent workability, particularly stretch flangeability, in a continuous annealing hot-dip galvanizing line. That is the purpose.
【０００９】[0009]
【課題を解決するための手段】本発明者は、前記課題を
解決するために、従来の連続焼鈍溶融亜鉛めっきライン
についてハード及びソフトの両面から再検討を加えた結
果、鋼板を連続的に洗浄−予熱−均熱−冷却−溶融亜鉛
めっき−合金化加熱等の一連の工程を経る溶融亜鉛めっ
きラインにおいて、均熱工程と溶融亜鉛めっき浸漬工程
の間で、強制冷却帯と加熱制御帯を設置した連続溶融亜
鉛めっきラインとすることにより、可能であることを知
見し、ここに本発明を完成したものである。In order to solve the above-mentioned problems, the present inventor has reconsidered the conventional continuous annealing hot-dip galvanizing line from both hard and soft sides, and as a result, continuously cleans the steel sheet. -Preheating-Soaking-Cooling-Hot dip galvanizing-On a hot dip galvanizing line that goes through a series of steps such as alloying heating, a forced cooling zone and a heating control zone are installed between the soaking step and the hot dip galvanizing dipping step. It was found that the continuous hot dip galvanizing line described above can be used, and the present invention has been completed here.
【００１０】すなわち、本発明は、Ｃ：０.０２〜０.３
０％、Ｓi：１.５０％以下、Ｍn：０.６０〜３.０％、
Ｐ：０.２０％以下、Ｓ：０.０５％以下、Ａl：０.０１
〜０.１０％を含有し、必要に応じて、更にＭo：０.０
１〜１.０％、Ｃr：０.１０〜１.５％、Ｎb：０.０１〜
０.０５％、Ｔi：０.０１〜０.５％、Ｂ：０.０００５
〜０.００３０％、Ｃa：０.０１％以下のうちの少なく
とも１種以上を含有し、残部がＦe及び不可避的不純物
よりなる組成を有する鋼につき、Ａc3点以上で熱間圧延
した熱延鋼板を酸洗、冷間圧延した後、連続焼鈍溶融亜
鉛めっきラインにおいて、再結晶温度以上かつＡc1点以
上に加熱保持し、その後、溶融亜鉛槽に至るまでの間に
おいて、Ｍs点以下に急冷して、鋼板中に部分的或いは
全部分マルテンサイトを生成させ、次いで、Ｍs点以上
の温度であって少なくとも溶融亜鉛浴温度及び合金化炉
温度に加熱して、部分的或いは全部焼戻しマルテンサイ
トを生成させることを特徴とする伸びフランジ性の優れ
た高強度合金化溶融亜鉛めっき鋼板の製造方法を要旨と
している。That is, according to the present invention, C: 0.02 to 0.3.
0%, Si: 1.50% or less, Mn: 0.60 to 3.0%,
P: 0.20% or less, S: 0.05% or less, Al: 0.01
~ 0.10%, if necessary, further Mo: 0.0
1-1.0%, Cr: 0.10-1.5%, Nb: 0.01-
0.05%, Ti: 0.01 to 0.5%, B: 0.0005
~0.0030%, Ca: contains at least one or more of 0.01% or less, per steel having a composition the balance of Fe and unavoidable impurities was hot rolled at Ac 3 point or more hot rolling After pickling and cold rolling the steel sheet, it is heated and held at a recrystallization temperature or higher and an Ac 1 point or higher in a continuous annealing hot-dip galvanizing line, and then rapidly cooled to a Ms point or lower until reaching the hot-dip galvanizing tank. Then, partially or wholly martensite is formed in the steel sheet, and then it is heated to at least the molten zinc bath temperature and the alloying furnace temperature at a temperature of Ms point or higher to partially or totally temper martensite. The gist is a method for producing a high-strength galvannealed steel sheet having excellent stretch-flangeability, which is characterized by being produced.
【００１１】また、他の本発明は、鋼板が連続的に洗浄
−予熱−均熱−冷却−溶融亜鉛めっき−合金化加熱等の
一連の工程を経る溶融亜鉛めっきラインにおいて、均熱
工程と溶融亜鉛めっき浸漬工程の間に、強制冷却帯と加
熱帯を設置し、該強制冷却帯は通板中の板温を溶融亜鉛
めっき浴温よりも１００℃以上降下させる手段を有し、
該加熱帯はめっき浴槽に鋼板を浸漬するまでに溶融亜鉛
めっき浴温以上に加熱する手段を有することを特徴とす
る連続溶融亜鉛めっき設備を要旨としている。Another aspect of the present invention is that in a hot dip galvanizing line in which a steel sheet undergoes a series of steps such as cleaning, preheating, soaking, cooling, hot dip galvanizing, alloying heating, etc. During the galvanizing dipping step, a forced cooling zone and a heating zone are installed, and the forced cooling zone has a means for lowering the plate temperature during stripping by 100 ° C. or more than the hot dip galvanizing bath temperature,
The heating zone is characterized by a means for heating the hot-dip galvanizing bath temperature or higher before the steel sheet is immersed in the galvanizing bath, which is a feature of continuous hot-dip galvanizing equipment.
【００１２】[0012]
【００１３】以下に本発明を更に詳細に説明する。ま
ず、本発明における鋼の化学成分の限定理由について説
明する。The present invention will be described in more detail below. First, the reasons for limiting the chemical composition of steel in the present invention will be described.
【００１４】Ｃ：Ｃ成分は鋼の強度を向上する作用を有
しているが、その含有量が０.０２％未満では所望の強
度を確保することができず、一方、０.３０％を超える
と溶接性の劣化を招くことから、Ｃ含有量は０.０２〜
０.３０％の範囲とする。C: C component has the effect of improving the strength of the steel, but if the content is less than 0.02%, the desired strength cannot be ensured, while 0.30% is required. If it exceeds, the weldability is deteriorated, so the C content is 0.02 to
The range is 0.30%.
【００１５】Ｓi：Ｓi成分は固溶体硬化を通じ、微量添
加であっても鋼の強度上昇と延性の向上に有効な働きを
する元素である。しかし、１.５０％を超えて含有する
と、溶接性の劣化を招くことから、Ｓi含有量は１.５０
％以下とする。なお、特に鋼板表面のスケール性に厳し
い要求がなされる場合には、０.０７％以下にすること
が好ましい。Si: The Si component is an element that effectively works to increase the strength and the ductility of steel even if added in a small amount through solid solution hardening. However, when the content exceeds 1.50%, the weldability is deteriorated, so the Si content is 1.50.
% Or less. It should be noted that, particularly when the scale property of the steel sheet surface is strictly demanded, it is preferably made 0.07% or less.
【００１６】Ｍn：Ｍn成分には固溶体強化、変態強化、
細粒強化により鋼の強度と靭性の両方を向上させる作用
がある。しかし、その含有量が０.６０％未満では所望
の効果が得られず、一方、３.０％を超えて含有すると
溶接性が劣化することから、Ｍn含有量は０.６０〜３.
０％の範囲とする。Mn: Mn components include solid solution strengthening, transformation strengthening,
Fine grain strengthening has the effect of improving both the strength and toughness of the steel. However, if its content is less than 0.60%, the desired effect cannot be obtained, while if it exceeds 3.0%, the weldability deteriorates, so the Mn content is 0.60-3.
The range is 0%.
【００１７】Ｐ：Ｐ成分は鋼の延性に対して好ましくな
い元素であり、可能な限り少ない方がよい。本発明にお
いては、熱延の低温巻取りにおいてＰの悪影響を軽減で
きること及び経済性を考慮して、上限を０.２０％とす
る。好ましくは０.０２０％以下である。P: P component is an element unfavorable to the ductility of steel, and it is preferable that the content is as small as possible. In the present invention, the upper limit is set to 0.20% in consideration of the fact that the adverse effect of P can be reduced in the low temperature winding of hot rolling and the economy. It is preferably 0.020% or less.
【００１８】Ｓ：Ｓ成分はＭnと結合してＡ系介在物を
生じ、延性の低下や耐縦割れ性の劣化を招くので、可及
的に少ない方がよい。経済性を考慮して、上限を０.０
５％とする。好ましくは０.００５％以下である。S: The S component is combined with Mn to form an A-type inclusion, which leads to a decrease in ductility and deterioration in vertical cracking resistance. Considering economy, the upper limit is 0.0
5%. It is preferably 0.005% or less.
【００１９】Ａl：Ａl成分は鋼の脱酸のために必要な元
素であり、十分な脱酸効果を確保するためには０.０１
％以上含有させる必要がある。しかし、０.１０％を超
えるとその効果が飽和すると共に、クラスター状の介在
物が多くなり、加工性が劣化するので、上限を０.１０
％とする。Al: The Al component is an element necessary for deoxidizing steel, and 0.01 is necessary for ensuring a sufficient deoxidizing effect.
% Or more must be contained. However, when the content exceeds 0.10%, the effect is saturated, and the number of cluster-like inclusions increases and the workability deteriorates, so the upper limit is 0.10.
%.
【００２０】本発明においては、必要に応じて、更に以
下の成分の少なくとも１種以上を含有させることができ
る。In the present invention, if necessary, at least one or more of the following components may be contained.
【００２１】Ｍo、Ｃr：Ｍo、Ｃrは、オーステナイト相
を安定化し、冷却過程での低温変態生成物の生成を容易
にするのに有効である。この効果を有効に発揮させるた
めには、Ｍoは０.０１％以上、Ｃrは０.１０％以上の添
加を必要とするが、一方、多すぎるときは、延性の低下
をもたらすと共に、これらの合金元素は高価であるの
で、その上限は、Ｍoについては１.０％、Ｃrについて
は１.５％とする。Mo, Cr: Mo, Cr are effective in stabilizing the austenite phase and facilitating the formation of low-temperature transformation products in the cooling process. In order to exert this effect effectively, it is necessary to add Mo in an amount of 0.01% or more and Cr in an amount of 0.10% or more. Since alloying elements are expensive, the upper limits are set to 1.0% for Mo and 1.5% for Cr.
【００２２】Ｎb：Ｎb成分は微量添加で大幅な強度上昇
と優れた低温靭性を付与する好ましい元素である。ま
た、局部延性の改善に有効なベイナイトなどの低温生成
相を生じ易くする。かかる効果が大いに期待できる量と
して０.０１％を下限とするが、０.０５％を超えて含有
させると溶接性が劣化するので、上限を０.０５％とす
る。Nb: The Nb component is a preferred element that imparts a large increase in strength and excellent low temperature toughness when added in a trace amount. Further, it facilitates the formation of a low temperature generation phase such as bainite, which is effective in improving the local ductility. The lower limit of 0.01% is the amount at which such effects can be expected, but the weldability deteriorates if the content exceeds 0.05%, so the upper limit is set to 0.05%.
【００２３】Ｔi：Ｔi成分は、Ｎbと同様、コイル内品
質の安定化・鋼の強化等のために添加する。その効果を
出すためには０.０１％以上が必要である。一方、０.５
％を超えるとその効果が飽和し、経済的にも不利である
ので、上限を０.５％とする。Ti: The Ti component, like Nb, is added to stabilize the quality inside the coil and strengthen the steel. To obtain the effect, 0.01% or more is required. On the other hand, 0.5
If it exceeds%, the effect is saturated and it is economically disadvantageous, so the upper limit is made 0.5%.
【００２４】Ｂ：Ｂ成分は鋼の焼入れ性を高め、所要の
組織を得るために有効であり、かかる効果を有効に発現
させるためには、少なくとも０.０００５％の添加が必
要である。しかし、過多に添加しても、焼入れ性向上効
果が飽和するのみならず、延性を劣化させるので、添加
量の上限を０.００３０％とする。B: B component is effective for enhancing the hardenability of steel and obtaining the required structure, and at least 0.0005% must be added in order to exert such effect effectively. However, even if added excessively, not only the effect of improving the hardenability is saturated, but also the ductility is deteriorated, so the upper limit of the addition amount is made 0.0003%.
【００２５】Ｃa：Ｃa成分は、介在物の形態制御によ
り、低温靭性、延性の向上に好ましいが、多すぎると鋼
中の介在物量が増加して延性の劣化が生じるので、上限
を０.０１％とする。The Ca: Ca component is preferable for improving the low temperature toughness and ductility by controlling the morphology of inclusions, but if it is too large, the amount of inclusions in the steel increases and ductility deteriorates, so the upper limit is 0.01. %.
【００２６】なお、場合によっては、Ｖを添加すること
ができる。Ｖは焼入れ性の向上や鋼の強靱化に効果があ
り、そのためには０.６％以下が望ましい。In some cases, V can be added. V has an effect of improving hardenability and toughening of steel, and for this purpose, V is preferably 0.6% or less.
【００２７】次に本発明における製造条件について説明
する。Next, the manufacturing conditions in the present invention will be described.
【００２８】鋼板の圧延等の条件については、通常の条
件でよく、上記鋼のＡc3点以上で熱間圧延を行う。次い
で、酸洗し、冷間圧延後、連続焼鈍溶融亜鉛めっきライ
ンに供される。The conditions such as rolling of the steel sheet may be ordinary conditions, and hot rolling is performed at the Ac 3 point or higher of the above steel. Then, it is pickled, cold-rolled, and then subjected to a continuous annealing hot-dip galvanizing line.
【００２９】連続焼鈍合金化溶融亜鉛めっきラインで
は、その熱履歴条件は以下の条件とする必要がある。In the continuous annealed alloy hot-dip galvanizing line, the thermal history conditions must be as follows.
【００３０】加熱温度(Ｔ)：鋼板の一部又は全部を均一
にマルテンサイト化して、その後の急冷、再加熱により
均質な焼戻しマルテンサイトを得るために、原板を再結
晶温度以上かつＡc1点以上に均熱加熱する必要がある。Heating temperature (T): In order to obtain a uniform tempered martensite by uniformly martensiticizing a part or the whole of the steel sheet and then quenching and reheating, the original plate is at the recrystallization temperature or higher and Ac 1 point. It is necessary to carry out soaking and heating above.
【００３１】冷却速度(ＣＲ)、冷却停止温度：上記原板
を加熱温度(Ｔ)からＭs点以下に急冷してマルテンサイ
トを生成させる。なお、短い通板時間で焼入れ、焼戻し
をするには、冷却停止温度はＭs点以下で且つできるだ
けめっき浴槽(ポット)温度に近い温度が望ましく、該温
度のもとで、冷却速度をコントロールしてマルテンサイ
トを生成させる。このためには、鋼の化学成分と冷却速
度の関係は、以下の関係を満足するのが好ましい。 ｌnＣＲ≧−１.１８Ｍneq＋３.３７ ここで、Ｍneq＝Ｍn＋１.１０Ｃr＋０.１０Ｓi＋２.１
Ｐ＋１.５２ (Ｃr、Ｓi、Ｐはwt％)Cooling rate (CR), cooling stop temperature: The above original plate is rapidly cooled from the heating temperature (T) to the Ms point or lower to generate martensite. For quenching and tempering in a short striping time, it is desirable that the cooling stop temperature is equal to or lower than the Ms point and is as close to the plating bath (pot) temperature as possible, and the cooling rate is controlled under this temperature. Generate martensite. For this purpose, the relationship between the chemical composition of steel and the cooling rate preferably satisfies the following relationship. lnCR ≧ −1.18 Mneq + 3.37 where Mneq = Mn + 1.10Cr + 0.10Si + 2.1
P + 1.52 (Cr, Si, P is wt%)
【００３２】次いで、Ｍs点以上の温度であって、少な
くともめっき浴槽(ポット)温度及び合金化炉温度に加熱
して焼戻して、部分的或いは全部焼戻しマルテンサイト
を生成させる。まず、めっき浴槽温度に加熱し、次いで
合金化炉温度に加熱する態様のほか、めっき浴槽温度以
上に加熱した後にめっき浴槽に浸漬し、次いで合金化炉
温度に加熱する態様も可能である。Next, it is heated to at least the plating bath temperature (pot) temperature and the alloying furnace temperature at a temperature equal to or higher than the Ms point and tempered to form a partially or fully tempered martensite. First, in addition to the mode of heating to the temperature of the plating bath and then to the temperature of the alloying furnace, the mode of heating to the temperature of the plating bath or higher, immersing in the plating bath and then heating to the temperature of the alloying furnace is also possible.
【００３３】上述の製造方法を実現するには、従来の溶
融亜鉛めっきプロセスに比べて、斬新なインライン加熱
プロセスを設置した連続焼鈍溶融亜鉛めっきラインによ
るのが好ましい。In order to realize the above-mentioned manufacturing method, it is preferable to use a continuous annealing hot dip galvanizing line equipped with a novel in-line heating process as compared with the conventional hot dip galvanizing process.
【００３４】すなわち、図２にライン構成例を示すよう
に、基本的には、均熱工程と溶融亜鉛めっき浸漬工程の
間に、強制冷却帯(Ｉ)と加熱制御帯(II)を連続的に設置
し、この強制冷却帯(Ｉ)では、その強制冷却停止温度が
溶融亜鉛めっき浴槽(ポット)温度よりも１００℃以上降
下させることが可能であり、また、加熱制御帯(II)で
は、溶融亜鉛めっき浴槽に浸漬するまでに溶融亜鉛めっ
き浴槽温度と等しいか若しくは該温度以上に加熱するこ
とが可能であるように構成されている。That is, as shown in the line configuration example in FIG. 2, basically, the forced cooling zone (I) and the heating control zone (II) are continuously provided between the soaking step and the hot dip galvanizing dipping step. In the forced cooling zone (I), the forced cooling stop temperature can be lowered by 100 ° C. or more than the hot dip galvanizing bath (pot) temperature, and in the heating control zone (II), It is configured so that it can be heated to a temperature equal to or higher than the temperature of the hot dip galvanizing bath before being immersed in the hot dip galvanizing bath.
【００３５】このライン構成とすることにより、図３に
示すような熱履歴が連続焼鈍溶融亜鉛めっきラインで可
能である。With this line configuration, the heat history as shown in FIG. 3 is possible in the continuous annealing hot-dip galvanizing line.
【００３６】すなわち、この連続焼鈍溶融亜鉛めっきラ
インにおいて、鋼板を再結晶温度以上かつＡc1点以上に
均熱加熱した後、強制冷却帯(Ｉ)にてＭs点以下まで強
制冷却してマルテンサイトを生成させ、次いで、めっき
ポット前の加熱制御帯(II)にて浴中温度に等しいか若し
くは該温度以上まで加熱することにより、マルテンサイ
トをその後のめっき処理時(亜鉛めっき浴槽又は合金化
炉)に焼戻しすることで、組織、炭化物形状、固溶Ｃを
制御し、局部延性の優れた高強度溶融亜鉛めっき鋼板を
安定して製造することができる。That is, in this continuous annealing hot-dip galvanizing line, the steel sheet is uniformly heated to the recrystallization temperature or higher and the Ac 1 point or higher, and then is forcibly cooled to the Ms point or lower in the forced cooling zone (I) to obtain martensite. And then heated to a temperature equal to or higher than the temperature in the bath in the heating control zone (II) before the plating pot, so that the martensite is subjected to the subsequent plating treatment (zinc plating bath or alloying furnace). ), The microstructure, carbide shape, and solid solution C can be controlled, and a high-strength hot-dip galvanized steel sheet having excellent local ductility can be stably manufactured.
【００３７】ここで、均熱工程と溶融亜鉛めっき浸漬工
程の間に強制冷却帯(I)及び加熱制御帯(II)を設置する
のは、最も優れた機械的特性値やλ値を示す焼戻しマ
ルテンサイト組織を得るためのマルテンサイトを得るた
め、めっき密着性を良好にするために鋼板が溶融亜鉛
めっき槽に浸漬される前に溶融亜鉛めっき浴温以上に板
を加熱することを可能とし、同時にマルテンサイトを焼
戻す必要があるためである。Here, the forced cooling zone (I) and the heating control zone (II) are installed between the soaking process and the hot dip galvanizing dipping process, because the tempering exhibiting the most excellent mechanical characteristic value and λ value. To obtain martensite for obtaining martensite structure, it is possible to heat the plate to a temperature higher than the hot dip galvanizing bath temperature before the steel plate is immersed in the hot dip galvanizing bath in order to improve the plating adhesion. This is because it is necessary to temper the martensite at the same time.
【００３８】また、強制冷却帯(Ｉ)にて、その強制冷却
停止温度を溶融亜鉛めっき浴槽(ポット)温度よりも１０
０℃以上降下させる構成とするのは、溶融亜鉛めっき浴
温は通常４５０℃前後であり、実用鋼では少なくともこ
の温度よりも１００℃以上低い温度でマルテンサイトは
得られるものであり、この必要なマルテンサイト組織を
確保するためである。In the forced cooling zone (I), the temperature at which the forced cooling is stopped is set to be 10 higher than the temperature of the hot dip galvanizing bath (pot).
The structure in which the temperature is lowered by 0 ° C. or more is that the temperature of the hot dip galvanizing bath is usually around 450 ° C., and martensite can be obtained at a temperature of 100 ° C. or more lower than this temperature in practical steel. This is to secure the martensite structure.
【００３９】次に本発明の実施例を示す。Next, examples of the present invention will be shown.
【００４０】[0040]
【００４１】実験室的に、表２に示す冷却停止温度とめ
っきポット前温度についての温度履歴を熱処理シュミレ
ータにより実施し、表１に示す化学成分を有する鋼を用
いて試験した。供試鋼板はいずれも、Ａc3点以上の熱延
後５８０℃で巻取り、フェライト＋パーライト組織の熱
延原板とし、７０％の冷間圧延を行ったものである。ま
た、めっきポット温度は４５０℃とした。In the laboratory, the temperature history about the cooling stop temperature and the temperature before the plating pot shown in Table 2 was carried out by a heat treatment simulator, and tested using a steel having the chemical composition shown in Table 1. Each of the test steel sheets was hot-rolled at 580 ° C. after hot-rolling at an Ac 3 point or more to obtain a hot-rolled original sheet having a ferrite + pearlite structure and cold-rolled at 70%. The plating pot temperature was 450 ° C.
【００４２】熱処理後の鋼板の機械的性質、表面品質を
表２に示す。なお、λ値は、次式により求めた。 λ＝｛(ｄ−ｄo)／ｄo｝×１００ ここで、ｄo：初期穴径(１０mm) ｄ：割れ発生時の穴径Table 2 shows the mechanical properties and surface quality of the steel sheet after heat treatment. The λ value was calculated by the following equation. λ = {(d-do) / do} × 100 where do: initial hole diameter (10 mm) d: hole diameter when crack occurs
【００４３】表２より、本発明例は、優れた加工性(λ
値＞８０％)と表面品質を有していることがわかる。一
方、鋼Ｇについての比較例では、一方の例は均熱温度が
低いためλ値が低く、他方の例はめっきポット前温度が
低いため表面性状が不良である。また他の比較例はいず
れも均熱温度が低いためにλ値が低い。From Table 2, the examples of the present invention have excellent workability (λ
It can be seen that it has a surface quality of (value> 80%). On the other hand, in the comparative example of the steel G, one example has a low soaking temperature and thus a low λ value, and the other example has a low surface temperature before the plating pot, resulting in poor surface quality. Further, in all the other comparative examples, the λ value is low because the soaking temperature is low.
【００４４】[0044]
【表１】 [Table 1]
【００４５】[0045]
【表２】 [Table 2]
【００４６】[0046]
【発明の効果】以上詳述したように、本発明によれば、
連続焼鈍溶融亜鉛めっきラインにて、優れた加工性、特
に伸びフランジ性の優れた高強度溶融亜鉛めっき鋼板を
製造することができる。特に、連続焼鈍溶融亜鉛めっき
ラインでインライン加熱プロセスを採用することにより
金属組織を制御することができるので、良好な亜鉛めっ
き層を有すると共に優れた加工性の高強度溶融亜鉛めっ
き鋼板を連続的に製造することが可能である。As described in detail above, according to the present invention,
A high-strength hot-dip galvanized steel sheet having excellent workability, particularly stretch flangeability, can be produced on a continuous annealing hot-dip galvanizing line. In particular, by adopting an in-line heating process in a continuous annealing hot dip galvanizing line, it is possible to control the metal structure, so that a high strength hot dip galvanized steel sheet having a good galvanizing layer and excellent workability can be continuously produced. It is possible to manufacture.
【図１】従来の溶融亜鉛めっきプロセスを説明する図で
ある。FIG. 1 is a diagram illustrating a conventional hot-dip galvanizing process.
【図２】本発明における連続焼鈍溶融亜鉛めっきライン
の好ましいライン構成を説明する図である。FIG. 2 is a diagram illustrating a preferred line configuration of a continuous annealing hot-dip galvanizing line in the present invention.
【図３】本発明における連続焼鈍溶融亜鉛めっきライン
の好ましい熱履歴を説明する図である。FIG. 3 is a diagram illustrating a preferable thermal history of the continuous annealing hot-dip galvanizing line in the present invention.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.5 識別記号 庁内整理番号 ＦＩ 技術表示箇所 // Ｃ２２Ｃ 38/00 ３０１ Ｔ 38/06 38/32 ─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. 5 Identification code Office reference number FI technical display location // C22C 38/00 301 T 38/06 38/32
Claims (3)
０.３０％、Ｓi：１.５０％以下、Ｍn：０.６０〜３.０
％、Ｐ：０.２０％以下、Ｓ：０.０５％以下、Ａl：０.
０１〜０.１０％を含有し、残部がＦe及び不可避的不純
物よりなる組成を有する鋼につき、Ａc3点以上で熱間圧
延した熱延鋼板を酸洗、冷間圧延した後、連続焼鈍溶融
亜鉛めっきラインにおいて、再結晶温度以上かつＡc1点
以上に加熱保持し、その後、溶融亜鉛槽に至るまでの間
において、Ｍs点以下に急冷して、鋼板中に部分的或い
は全部分マルテンサイトを生成させ、次いで、Ｍs点以
上の温度であって少なくとも溶融亜鉛浴温度及び合金化
炉温度に加熱して、部分的或いは全部焼戻しマルテンサ
イトを生成させることを特徴とする伸びフランジ性の優
れた高強度合金化溶融亜鉛めっき鋼板の製造方法。1. In weight% (hereinafter the same), C: 0.02 to
0.30%, Si: 1.50% or less, Mn: 0.60 to 3.0
%, P: 0.20% or less, S: 0.05% or less, Al: 0.0.
For steel having a composition containing 01 to 0.10% and the balance being Fe and unavoidable impurities, hot-rolled hot-rolled steel sheet hot-rolled at Ac 3 points or more is pickled, cold-rolled, and then continuously annealed and melted. In the galvanizing line, it is heated and maintained at the recrystallization temperature or higher and the Ac 1 point or higher, and then it is rapidly cooled to the Ms point or lower until reaching the hot dip galvanizing bath to partially or completely martensite the steel sheet. It is produced and then heated to at least the molten zinc bath temperature and the alloying furnace temperature at a temperature not lower than the Ms point to produce partially or completely tempered martensite, which is excellent in stretch-flange formability and high. A method for manufacturing a high-strength galvanized steel sheet.
％、Ｃr：０.１０〜１.５％、Ｎb：０.０１〜０.０５
％、Ｔi：０.０１〜０.５％、Ｂ：０.０００５〜０.０
０３０％、Ｃa：０.０１％以下のうちの少なくとも１種
以上を含有している請求項１に記載の方法。2. The steel further comprises Mo: 0.01 to 1.0.
%, Cr: 0.10 to 1.5%, Nb: 0.01 to 0.05
%, Ti: 0.01 to 0.5%, B: 0.0005 to 0.0
The method according to claim 1, containing at least one of 030% and Ca: 0.01% or less.
−溶融亜鉛めっき−合金化加熱等の一連の工程を経る溶
融亜鉛めっきラインにおいて、均熱工程と溶融亜鉛めっ
き浸漬工程の間に、強制冷却帯と加熱帯を設置し、該強
制冷却帯は通板中の板温を溶融亜鉛めっき浴温よりも１
００℃以上降下させる手段を有し、該加熱帯はめっき浴
槽に鋼板を浸漬するまでに溶融亜鉛めっき浴温以上に加
熱する手段を有することを特徴とする連続溶融亜鉛めっ
き設備。3. A hot-dip galvanizing line in which a steel sheet undergoes a series of steps such as continuous cleaning-preheating-soaking-cooling-hot dip galvanizing-alloying heating, etc., between the soaking step and the hot dip galvanizing step. In addition, a forced cooling zone and a heating zone are installed, and the forced cooling zone has a plate temperature of 1% higher than the hot dip galvanizing bath temperature.
A continuous hot-dip galvanizing facility comprising means for lowering the temperature to 00 ° C. or more, and the heating zone having means for heating the hot-dip galvanizing bath temperature to a temperature equal to or higher than that of the hot-dip galvanizing bath until the steel sheet is immersed in the galvanizing bath.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27241892A JPH0693340A (en) | 1992-09-14 | 1992-09-14 | Method and equipment for manufacturing high strength galvannealed steel sheet having stretch flanging formability |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27241892A JPH0693340A (en) | 1992-09-14 | 1992-09-14 | Method and equipment for manufacturing high strength galvannealed steel sheet having stretch flanging formability |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0693340A true JPH0693340A (en) | 1994-04-05 |
Family
ID=17513638
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27241892A Withdrawn JPH0693340A (en) | 1992-09-14 | 1992-09-14 | Method and equipment for manufacturing high strength galvannealed steel sheet having stretch flanging formability |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0693340A (en) |
Cited By (24)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6423426B1 (en) | 1999-04-21 | 2002-07-23 | Kawasaki Steel Corporation | High tensile hot-dip zinc-coated steel plate excellent in ductility and method for production thereof |
| WO2008123561A1 (en) | 2007-03-30 | 2008-10-16 | Jfe Steel Corporation | High-strength hot-dip zinc-coated steel sheet |
| WO2009054539A1 (en) | 2007-10-25 | 2009-04-30 | Jfe Steel Corporation | High-strength hot-dip zinc plated steel sheet excellent in workability and process for manufacturing the same |
| JP2009120878A (en) * | 2007-11-13 | 2009-06-04 | Jfe Steel Corp | High strength hot-dip galvanized steel sheet with excellent workability, and its manufacturing method |
| WO2009081997A1 (en) | 2007-12-20 | 2009-07-02 | Jfe Steel Corporation | Processes for producing high-strength hot-dip galvanized steel sheet and high-strength galvannealed steel sheet |
| WO2009096595A1 (en) * | 2008-01-31 | 2009-08-06 | Jfe Steel Corporation | High-strength steel sheet and process for production thereof |
| WO2009096344A1 (en) | 2008-01-31 | 2009-08-06 | Jfe Steel Corporation | High-strength hot-dip galvanized steel sheet with excellent processability and process for producing the same |
| WO2009096596A1 (en) | 2008-01-31 | 2009-08-06 | Jfe Steel Corporation | High-strength steel sheet and process for production thereof |
| WO2009099079A1 (en) * | 2008-02-08 | 2009-08-13 | Jfe Steel Corporation | High-strength hot-dip galvanized steel sheet with excellent processability and process for producing the same |
| JP2010013700A (en) * | 2008-07-03 | 2010-01-21 | Jfe Steel Corp | High strength hot dip galvanized steel sheet having excellent workability, and method for producing the same |
| EP2216422A1 (en) * | 2007-11-22 | 2010-08-11 | Kabushiki Kaisha Kobe Seiko Sho | High-strength cold-rolled steel sheet |
| WO2010146796A1 (en) | 2009-06-17 | 2010-12-23 | Ｊｆｅスチール株式会社 | High-strength hot-dip galvannealed steel shhet with excellent workability and fatigue characteristics and process for production thereof |
| WO2011013845A1 (en) | 2009-07-30 | 2011-02-03 | Ｊｆｅスチール株式会社 | High-strength steel sheet, and process for production thereof |
| GB2477664A (en) * | 2009-03-31 | 2011-08-10 | Kobe Steel Ltd | Cold rolled steel sheet with relationship between inclusion separation distance and yield strength |
| US8025835B2 (en) | 2007-07-31 | 2011-09-27 | ArcelorMittal Investigación y Desarrollo, S.L. | Furnace configured for use in both the galvannealing and galvanizing of a metal strip |
| EP2524970A1 (en) * | 2011-05-18 | 2012-11-21 | ThyssenKrupp Steel Europe AG | Extremely stable steel flat product and method for its production |
| US8460800B2 (en) | 2009-03-31 | 2013-06-11 | Kobe Steel, Ltd. | High-strength cold-rolled steel sheet excellent in bending workability |
| CN107109586A (en) * | 2015-01-14 | 2017-08-29 | Ak钢铁产权公司 | Dual phase steel with improvement property |
| KR20170130508A (en) | 2015-04-22 | 2017-11-28 | 신닛테츠스미킨 카부시키카이샤 | Coated steel plate |
| WO2019238741A1 (en) * | 2018-06-12 | 2019-12-19 | Thyssenkrupp Steel Europe Ag | Flat steel product and method for the production thereof |
| US10883950B2 (en) | 2011-08-30 | 2021-01-05 | Watlow Electric Manufacturing Company | Multi-parallel sensor array system |
| WO2022131543A1 (en) * | 2020-12-18 | 2022-06-23 | 주식회사 포스코 | High-hardness armored steel having excellent low-temperature impact toughness, and manufacturing method therefor |
| US11371113B2 (en) | 2016-12-14 | 2022-06-28 | Evonik Operations Gmbh | Hot-rolled flat steel product and method for the production thereof |
| CN115181895A (en) * | 2021-04-02 | 2022-10-14 | 宝山钢铁股份有限公司 | 1180 MPa-grade low-carbon low-alloy hot-dip galvanized Q & P steel and rapid heat treatment hot-dip galvanizing manufacturing method |
-
1992
- 1992-09-14 JP JP27241892A patent/JPH0693340A/en not_active Withdrawn
Cited By (48)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6423426B1 (en) | 1999-04-21 | 2002-07-23 | Kawasaki Steel Corporation | High tensile hot-dip zinc-coated steel plate excellent in ductility and method for production thereof |
| WO2008123561A1 (en) | 2007-03-30 | 2008-10-16 | Jfe Steel Corporation | High-strength hot-dip zinc-coated steel sheet |
| US8076008B2 (en) | 2007-03-30 | 2011-12-13 | Jfe Steel Corporation | Galvanized high strength steel sheet |
| US8025835B2 (en) | 2007-07-31 | 2011-09-27 | ArcelorMittal Investigación y Desarrollo, S.L. | Furnace configured for use in both the galvannealing and galvanizing of a metal strip |
| WO2009054539A1 (en) | 2007-10-25 | 2009-04-30 | Jfe Steel Corporation | High-strength hot-dip zinc plated steel sheet excellent in workability and process for manufacturing the same |
| EP3696292A1 (en) | 2007-10-25 | 2020-08-19 | JFE Steel Corporation | A high tensile strength galvanized steel sheet with excellent formability and anti-crush properties and method of manufacturing the same |
| US9458521B2 (en) | 2007-10-25 | 2016-10-04 | Jfe Steel Corporation | High tensile strength galvanized steel sheets excellent in formability and methods of manufacturing the same |
| JP2009120878A (en) * | 2007-11-13 | 2009-06-04 | Jfe Steel Corp | High strength hot-dip galvanized steel sheet with excellent workability, and its manufacturing method |
| US8679265B2 (en) | 2007-11-22 | 2014-03-25 | Kobe Steel, Ltd. | High-strength cold-rolled steel sheet |
| EP2455507A1 (en) * | 2007-11-22 | 2012-05-23 | Kabushiki Kaisha Kobe Seiko Sho | High-strength cold-rolled steel sheet |
| EP2216422A4 (en) * | 2007-11-22 | 2011-08-03 | Kobe Steel Ltd | High-strength cold-rolled steel sheet |
| EP2216422A1 (en) * | 2007-11-22 | 2010-08-11 | Kabushiki Kaisha Kobe Seiko Sho | High-strength cold-rolled steel sheet |
| WO2009081997A1 (en) | 2007-12-20 | 2009-07-02 | Jfe Steel Corporation | Processes for producing high-strength hot-dip galvanized steel sheet and high-strength galvannealed steel sheet |
| US8430975B2 (en) | 2008-01-31 | 2013-04-30 | Jfe Steel Corporation | High strength galvanized steel sheet with excellent formability |
| JP2009203549A (en) * | 2008-01-31 | 2009-09-10 | Jfe Steel Corp | High-strength steel sheet and process for production thereof |
| WO2009096344A1 (en) | 2008-01-31 | 2009-08-06 | Jfe Steel Corporation | High-strength hot-dip galvanized steel sheet with excellent processability and process for producing the same |
| US9028626B2 (en) | 2008-01-31 | 2015-05-12 | Jfe Steel Corporation | Method for manufacturing high strength galvanized steel sheet with excellent formability |
| US8840834B2 (en) | 2008-01-31 | 2014-09-23 | JFE Steel Coporation | High-strength steel sheet and method for manufacturing the same |
| WO2009096596A1 (en) | 2008-01-31 | 2009-08-06 | Jfe Steel Corporation | High-strength steel sheet and process for production thereof |
| WO2009096595A1 (en) * | 2008-01-31 | 2009-08-06 | Jfe Steel Corporation | High-strength steel sheet and process for production thereof |
| JP2009209450A (en) * | 2008-02-08 | 2009-09-17 | Jfe Steel Corp | High-strength hot-dip galvanized steel sheet with excellent processability and method for producing the same |
| KR101218448B1 (en) * | 2008-02-08 | 2013-01-04 | 제이에프이 스틸 가부시키가이샤 | High-strength hot-dip galvanized steel sheet with excellent processability and process for producing the same |
| WO2009099079A1 (en) * | 2008-02-08 | 2009-08-13 | Jfe Steel Corporation | High-strength hot-dip galvanized steel sheet with excellent processability and process for producing the same |
| TWI464296B (en) * | 2008-02-08 | 2014-12-11 | Jfe Steel Corp | High strength galvanized steel sheet with excellent formability and method for manufacturing the same |
| US9011614B2 (en) | 2008-02-08 | 2015-04-21 | Jfe Steel Corporation | High-strength galvanized steel sheet with excellent formability and method for manufacturing the same |
| JP2010013700A (en) * | 2008-07-03 | 2010-01-21 | Jfe Steel Corp | High strength hot dip galvanized steel sheet having excellent workability, and method for producing the same |
| GB2477664B (en) * | 2009-03-31 | 2012-01-18 | Kobe Steel Ltd | High-strength cold-rolled steel sheet excellent in bending workability |
| US8460800B2 (en) | 2009-03-31 | 2013-06-11 | Kobe Steel, Ltd. | High-strength cold-rolled steel sheet excellent in bending workability |
| GB2477664A (en) * | 2009-03-31 | 2011-08-10 | Kobe Steel Ltd | Cold rolled steel sheet with relationship between inclusion separation distance and yield strength |
| US9580785B2 (en) | 2009-06-17 | 2017-02-28 | Jfe Steel Corporation | High-strength galvannealed steel sheet having excellent formability and fatigue resistance and method for manufacturing the same |
| US8968494B2 (en) | 2009-06-17 | 2015-03-03 | Jfe Steel Corporation | High-strength galvannealed steel sheet having excellent formability and fatigue resistance and method for manufacturing the same |
| WO2010146796A1 (en) | 2009-06-17 | 2010-12-23 | Ｊｆｅスチール株式会社 | High-strength hot-dip galvannealed steel shhet with excellent workability and fatigue characteristics and process for production thereof |
| WO2011013845A1 (en) | 2009-07-30 | 2011-02-03 | Ｊｆｅスチール株式会社 | High-strength steel sheet, and process for production thereof |
| WO2012156428A1 (en) * | 2011-05-18 | 2012-11-22 | Thyssenkrupp Steel Europe Ag | High-strength flat steel product and method for producing same |
| US9650708B2 (en) | 2011-05-18 | 2017-05-16 | Thyssenkrupp Steel Europe Ag | High-strength flat steel product and method for producing same |
| EP2524970A1 (en) * | 2011-05-18 | 2012-11-21 | ThyssenKrupp Steel Europe AG | Extremely stable steel flat product and method for its production |
| US10883950B2 (en) | 2011-08-30 | 2021-01-05 | Watlow Electric Manufacturing Company | Multi-parallel sensor array system |
| CN107109586A (en) * | 2015-01-14 | 2017-08-29 | Ak钢铁产权公司 | Dual phase steel with improvement property |
| AU2016206736B2 (en) * | 2015-01-14 | 2019-02-14 | Ak Steel Properties, Inc. | Dual phase steel with improved properties |
| CN110218942A (en) * | 2015-01-14 | 2019-09-10 | Ak钢铁产权公司 | With the dual phase steel for improving property |
| KR20170130508A (en) | 2015-04-22 | 2017-11-28 | 신닛테츠스미킨 카부시키카이샤 | Coated steel plate |
| US10501832B2 (en) | 2015-04-22 | 2019-12-10 | Nippon Steel Corporation | Plated steel sheet |
| US11371113B2 (en) | 2016-12-14 | 2022-06-28 | Evonik Operations Gmbh | Hot-rolled flat steel product and method for the production thereof |
| WO2019238741A1 (en) * | 2018-06-12 | 2019-12-19 | Thyssenkrupp Steel Europe Ag | Flat steel product and method for the production thereof |
| US11597986B2 (en) | 2018-06-12 | 2023-03-07 | Thyssenkrupp Steel Europe Ag | Flat steel product and method for producing same |
| WO2022131543A1 (en) * | 2020-12-18 | 2022-06-23 | 주식회사 포스코 | High-hardness armored steel having excellent low-temperature impact toughness, and manufacturing method therefor |
| CN115181895A (en) * | 2021-04-02 | 2022-10-14 | 宝山钢铁股份有限公司 | 1180 MPa-grade low-carbon low-alloy hot-dip galvanized Q & P steel and rapid heat treatment hot-dip galvanizing manufacturing method |
| CN115181895B (en) * | 2021-04-02 | 2023-09-12 | 宝山钢铁股份有限公司 | 1180 MPa-level low-carbon low-alloy hot dip galvanized Q & P steel and rapid heat treatment hot dip galvanizing manufacturing method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11692235B2 (en) | Method for manufacturing a high-strength steel sheet and sheet obtained by the method | |
| JPH0693340A (en) | Method and equipment for manufacturing high strength galvannealed steel sheet having stretch flanging formability | |
| JP5332355B2 (en) | High-strength hot-dip galvanized steel sheet and manufacturing method thereof | |
| JP3750789B2 (en) | Hot-dip galvanized steel sheet having excellent ductility and method for producing the same | |
| JP2019505693A (en) | Method for producing a coated high strength steel sheet with improved ductility and formability and the resulting coated steel sheet | |
| US20060140814A1 (en) | Steel composition for the production of cold rolled multiphase steel products | |
| JP2020147852A (en) | Method for producing coated steel sheet having improved strength, ductility and formability | |
| JPH06108152A (en) | Production of high strength hot-dipping galvanized steel sheet excellent in bending workability | |
| JP4855442B2 (en) | Low yield ratio alloyed hot dip galvanized high strength steel sheet manufacturing method | |
| CN115066507B (en) | High-strength cold-rolled and galvanized diffusion annealed steel sheet and method for producing same | |
| JP4265153B2 (en) | High-tensile cold-rolled steel sheet with excellent elongation and stretch flangeability and method for producing the same | |
| JP4265152B2 (en) | High-tensile cold-rolled steel sheet with excellent elongation and stretch flangeability and method for producing the same | |
| JP3263143B2 (en) | Bake hardening type high strength alloyed hot-dip galvanized steel sheet excellent in workability and method for producing the same | |
| JP2004323944A (en) | Hot dip galvanized steel sheet for quenching, its production method, and its use | |
| JP6704997B2 (en) | Method for producing ultra-high strength galvannealed steel sheet, and resulting alloyed hot-dip galvanized steel sheet | |
| JP3912181B2 (en) | Composite structure type high-tensile hot-dip galvanized cold-rolled steel sheet excellent in deep drawability and stretch flangeability and manufacturing method thereof | |
| JP2563021B2 (en) | Method for producing high-strength hot-rolled hot-dip galvannealed steel sheet with excellent stretch flangeability | |
| JPH05311244A (en) | Manufacture of galvannealed steel sheet excellent in stretch flanging property using high strength hot rolled original steel sheet | |
| JP4140962B2 (en) | Manufacturing method of low yield ratio type high strength galvannealed steel sheet | |
| JP2003342644A (en) | Process for manufacturing multiphase high tensile hot- dip galvanized cold-rolled steel sheet with good appearance of plating film and excellent deep- drawability | |
| JP3464611B2 (en) | High-strength hot-dip galvanized steel sheet excellent in formability and corrosion resistance and method for producing the same | |
| JP2005206920A (en) | High-tensile-strength hot-dip galvanized hot-rolled steel sheet with low yield ratio and composite structure superior in extension flange, and manufacturing method therefor | |
| JP2003193189A (en) | High tensile strength galvanized steel sheet with composite structure having excellent deep drawability and production method therefor | |
| JP2806121B2 (en) | Method for producing high-strength hot-dip galvanized steel with excellent workability and material stability | |
| JPH05105960A (en) | Production of high strength hot-dip galvanized steel sheet |
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: 19991130 |