JP3114507B2 - Cold rolled steel sheet with excellent surface properties - Google Patents
Cold rolled steel sheet with excellent surface propertiesInfo
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- JP3114507B2 JP3114507B2 JP06180044A JP18004494A JP3114507B2 JP 3114507 B2 JP3114507 B2 JP 3114507B2 JP 06180044 A JP06180044 A JP 06180044A JP 18004494 A JP18004494 A JP 18004494A JP 3114507 B2 JP3114507 B2 JP 3114507B2
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Description
【０００１】[0001]
【産業上の利用分野】本発明は、自動車部品や電気機器
部品などに用いられる表面性状に優れた極低炭素冷延鋼
板に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultra-low carbon cold rolled steel sheet having excellent surface properties used for automobile parts, electric equipment parts and the like.
【０００２】[0002]
【従来の技術】今日の製鋼脱ガス技術の進歩により、鋼
中の炭素量を30ppm以下まで低減した極低炭素鋼が比較
的安価でかつ大量に製造されるようになり、さらに優れ
た成形性を付与するために、Nb、Tiなどの炭窒化物形成
元素を添加した所謂IF鋼を用いた極低炭素冷延鋼板が自
動車部品や電気機器部品等の用途に広く用いられるよう
になってきている。2. Description of the Related Art With the progress of steelmaking degassing technology today, ultra-low carbon steels in which the amount of carbon in steel has been reduced to 30 ppm or less have become relatively inexpensive and mass-produced. Ultra-low carbon cold-rolled steel sheets using so-called IF steel to which carbonitride forming elements such as Nb and Ti are added in order to provide a steel sheet have been widely used in applications such as automobile parts and electric equipment parts. I have.
【０００３】例えば、特開昭61-246344号公報（先行技
術１）、特開平1-149943号公報（先行技術２）では、成
形性および耐２次加工脆性の向上に焦点をあて、Ti-Bを
添加した極低炭素冷延鋼板に関する技術が開示され、B
は耐２次加工脆性の向上のために添加されている。For example, JP-A-61-246344 (Prior Art 1) and JP-A-1-149943 (Prior Art 2) focus on improvement of formability and resistance to secondary working embrittlement, The technology regarding ultra-low carbon cold rolled steel sheet with B added is disclosed,
Is added to improve the resistance to secondary working brittleness.
【０００４】また、特開平2-232342号公報（以下、先行
技術３という）、特開昭60-92453号公報（以下、先行技
術４という）では、NiあるいはCrを単独添加した極低炭
素冷延鋼板に関する技術が開示され、Ni、Crはいずれも
ロウ付け溶接性を改善するために添加されている。In Japanese Patent Application Laid-Open No. Hei 2-232342 (hereinafter referred to as Prior Art 3) and Japanese Patent Application Laid-Open No. Sho 60-92453 (hereinafter referred to as Prior Art 4), an ultra-low carbon cooling system to which only Ni or Cr is added is disclosed. A technique relating to a rolled steel sheet is disclosed, and both Ni and Cr are added to improve brazing weldability.
【０００５】さらに、特開平6-25753 号公報（以下、先
行技術５という）、特開平6-25754号公報（以下、先行
技術６という）では、必須成分ではないものの、NiとCr
を複合添加した極低炭素冷延鋼板に関する技術が開示さ
れている。その実施例についてみるとTi-Nb-V を複合添
加したうえで、NiおよびCrをそれぞれ0.5%、0.2%添加し
ている。NiとCrの添加は耐食性向上および高強度化を目
的とするものである。Further, in Japanese Patent Application Laid-Open Nos. Hei 6-25753 (hereinafter referred to as Prior Art 5) and Japanese Patent Laid-Open Publication No. Hei 6-25754 (hereinafter referred to as Prior Art 6), Ni and Cr are not essential components.
A technology relating to an ultra-low carbon cold-rolled steel sheet to which iron is added in combination is disclosed. In this example, after adding Ti-Nb-V in a composite manner, Ni and Cr were added in 0.5% and 0.2%, respectively. The addition of Ni and Cr aims at improving corrosion resistance and increasing strength.
【０００６】[0006]
【発明が解決しようとする課題】ところで、自動車部品
や電気機器部品などに用いられる鋼板は良好な表面性状
が要求されることが多い。ところが、極低炭素冷延鋼板
は鋼が高純度であることが原因で表面性状の不良が発生
しやすい。Incidentally, steel sheets used for automobile parts, electric equipment parts, and the like often require good surface properties. However, extremely low carbon cold rolled steel sheets are liable to have poor surface properties due to the high purity of the steel.
【０００７】極低炭素冷延鋼板に発生する表面性状不良
の一つに表面むらがある。この表面むらは、めっきある
いは化成処理後もむらとして残存し、著しく商品価値を
損なうという問題点がある。この表面むらについてはこ
れまで必ずしも明らかにはされていない。[0007] One of the surface property defects that occur in extremely low carbon cold rolled steel sheets is surface unevenness. The surface unevenness remains as unevenness even after plating or chemical conversion treatment, and there is a problem that the commercial value is significantly impaired. The surface unevenness has not always been clarified.
【０００８】本発明はこのような実情を鑑み、極低炭素
冷延鋼板で多く発生する表面むらの低減を目的とし、表
面性状を向上させるうえで好ましい成分組成の冷延鋼板
を提供するものであるThe present invention has been made in view of the above circumstances, and aims to reduce surface unevenness which often occurs in extremely low-carbon cold-rolled steel sheets, and to provide a cold-rolled steel sheet having a component composition preferable for improving surface properties. is there
【０００９】[0009]
【課題を解決するための手段】本発明者等は、極低炭素
冷延鋼板の表面性状の安定化を目的として、極低炭素冷
延鋼板に発生する表面むらについて検討した結果、以下
のことがわかった。Means for Solving the Problems The inventors of the present invention have studied the surface unevenness of ultra low carbon cold rolled steel sheet for the purpose of stabilizing the surface properties of the ultra low carbon cold rolled steel sheet. I understood.
【００１０】冷延鋼板は、冷間圧延後、焼鈍前に圧延油
の除去を目的として、アルカリ洗浄が施されるが、この
アルカリ洗浄により鋼板表面が極めて活性な状態になる
ため、局部的な酸化反応により錆が鋼板表面に発生す
る。特に、極低炭素冷延鋼板は、鋼が高純化されている
ために、その発生頻度が高い。この錆の発生の起点は、
清浄化された粒界あるいは鋼板表面に存在する酸化物で
ある。この錆は、その後の還元雰囲気で焼鈍後も消える
ことがなく、めっきあるいは化成処理後も残存し、鋼板
の表面むらとなる。[0010] The cold-rolled steel sheet is subjected to alkali cleaning for the purpose of removing rolling oil after cold rolling and before annealing. However, since the surface of the steel sheet is extremely activated by the alkali cleaning, local cold-rolled steel sheets are locally localized. Rust is generated on the steel sheet surface by the oxidation reaction. In particular, extremely low-carbon cold-rolled steel sheets are frequently generated because the steel is highly purified. The starting point of this rust is
It is an oxide present on the grain boundaries that have been cleaned or on the steel sheet surface. This rust does not disappear even after annealing in a subsequent reducing atmosphere, and remains after plating or chemical conversion treatment, resulting in uneven surface of the steel sheet.
【００１１】したがって、表面むらの改善のためには、
アルカリ洗浄後の錆発生の不均一化を抑制することが重
要であり、具体的には錆の起点となる粒界の清浄化を抑
えるとともに、酸化物を低減し、さらに錆の生成を抑制
のため、O 量に応じてNiとCrを複合添加すること、およ
び微量のB を添加することが有効である。Therefore, in order to improve the surface unevenness,
It is important to suppress the non-uniformity of rust generation after alkali washing.Specifically, it is necessary to suppress the purification of grain boundaries that are the starting point of rust, reduce oxides, and further suppress rust generation. Therefore, it is effective to add Ni and Cr in combination according to the amount of O 2 and to add a small amount of B 2.
【００１２】なお、前記の先行技術と本発明の成分を比
べた場合、先行技術３とはNi量、先行技術４とはCr量が
重複するが、これらの先行技術は何れもNiまたはCrの単
独添加であるのに対して、本発明はNiとCrの複合添加で
ある点で相違している。また、先行技術5 、6 はNiとCr
の複合添加を開示しているが、その実施例はTi-Nb-Vの
複合添加であり、本発明の成分とは基本成分系は異な
り、さらに、Ni、Crの量は何れも本発明の範囲を外れる
ものである。また、これらの先行技術はいずれも本発明
が目的とする表面性状の改善とは目的が異なるものであ
る。When comparing the components of the present invention with the above-mentioned prior art, the amount of Ni is overlapped with that of Prior Art 3 and the amount of Cr is overlapped with that of Prior Art 4. However, each of these prior arts contains Ni or Cr. The present invention is different from the single addition in that it is a composite addition of Ni and Cr. Prior arts 5 and 6 are Ni and Cr
Although the compound addition of is disclosed, the example is the compound addition of Ti-Nb-V, the basic component system is different from the component of the present invention, and the amounts of Ni and Cr are all the same as those of the present invention. It is out of range. Further, all of these prior arts have a different purpose from the improvement of surface properties aimed at by the present invention.
【００１３】本発明はこのような知見に基ずいてなされ
たものであり、その特徴とする構成は以下のとおりであ
る。The present invention has been made on the basis of such findings, and the features of the invention are as follows.
【００１４】（１）重量％で、C:0.003%以下、Mn:0.05
〜2.2%、Si:0.8%以下、P:0.1%以下、S:0.015%以下、so
l.Al:0.01〜0.1%、N:0.003%以下、Ti:0.005〜0.12%、B:
0.0002〜0.0009%、Ni:0.01〜0.15%、Cr:0.01〜0.2%、O:
0.0002%以上を含み、かつ前記のNi、Cr、O が、［%O]≦
0.002 ×[%Ni+%Cr] ＋0.0018なる関係を満足し、残部鉄
および不可避的不純物からなる表面性状に優れた冷延鋼
板。(1) By weight%, C: 0.003% or less, Mn: 0.05
~ 2.2%, Si: 0.8% or less, P: 0.1% or less, S: 0.015% or less, so
l.Al:0.01~0.1%, N: 0.003% or less, Ti: 0.005 ~ 0.12%, B:
0.0002-0.0009%, Ni: 0.01-0.15%, Cr: 0.01-0.2%, O:
0.0002% or more, and said Ni, Cr, O is [% O] ≦
A cold-rolled steel sheet that satisfies the relationship of 0.002 × [% Ni +% Cr] + 0.0018 and has excellent surface properties consisting of the balance of iron and unavoidable impurities.
【００１５】（２）重量％で、C:0.003%以下、Mn:0.05
〜2.2%、Si:0.8%以下、P:0.1%以下、S:0.015%以下、so
l.Al:0.01〜0.1%、N:0.003%以下、Ti:0.005〜0.12%、B:
0.0002〜0.0009%、Ni:0.01〜0.15%、Cr:0.01〜0.2%、O:
0.0002%以上を含み、かつ前記のNi、Cr、O が、［%O]≦
0.002 ×[%Ni+%Cr] ＋0.0018なる関係を満足し、さら
に，Nb:0.002〜0.02%を含み、残部鉄および不可避的不
純物からなる表面性状に優れた冷延鋼板。(2) By weight%, C: 0.003% or less, Mn: 0.05
~ 2.2%, Si: 0.8% or less, P: 0.1% or less, S: 0.015% or less, so
l.Al:0.01~0.1%, N: 0.003% or less, Ti: 0.005 ~ 0.12%, B:
0.0002-0.0009%, Ni: 0.01-0.15%, Cr: 0.01-0.2%, O:
0.0002% or more, and said Ni, Cr, O is [% O] ≦
A cold-rolled steel sheet that satisfies the relationship of 0.002 × [% Ni +% Cr] +0.0018, further contains 0.002 to 0.02% of Nb, and has excellent surface properties consisting of the balance of iron and unavoidable impurities.
【００１６】[0016]
【作用】以下に本発明について詳細に説明する。The present invention will be described below in detail.
【００１７】O は鋼中で酸化物（主にアルミナ）として
存在するが、酸化物が鋼板表面に存在する場合はアルカ
リ洗浄後の錆発生の起点となる。O が高いと鋼板表面に
存在する酸化物が増加するため、これが起点となって錆
が多く発生する。逆にO が低すぎると錆の発生個数は減
少するものの、そのサイズが大きく、目立ちやすくな
る。本発明の目的とする効果を発揮するためには、O は
0.0002%以上必要である。また、O の上限は下記に示すC
rおよびNiに応じた量とする。O is present in the steel as an oxide (mainly alumina). If the oxide is present on the surface of the steel sheet, it becomes a starting point of rust generation after alkali washing. If O 2 is high, the amount of oxides present on the surface of the steel sheet increases, and this leads to a large amount of rust. Conversely, if O 2 is too low, the number of rusts generated will decrease, but the size will be large and conspicuous. In order to achieve the desired effect of the present invention, O
0.0002% or more is required. Also, the upper limit of O is C shown below.
The amount depends on r and Ni.
【００１８】NiおよびCrは複合添加することにより、ア
ルカリ洗浄後の錆の生成を抑制する効果がある。これは
NiとCrがアルカリ洗浄後の酸化皮膜を緻密化するため、
目視で確認できる程度の錆にまで成長させないためであ
ると推定される。なお、単独添加ではその効果が認めら
れない。目的とする効果を得るには、それぞれ0.01%以
上必要である。また、添加量が多すぎると、理由はかな
らずしも明らかではないが、鋼板の端部などに局部的に
錆が集中して発生するようになるので、上限をそれぞれ
0.15%および0.2%とする必要がある。The combined addition of Ni and Cr has the effect of suppressing the formation of rust after alkali washing. this is
Since Ni and Cr densify the oxide film after alkali cleaning,
It is presumed that this is because the rust does not grow to such an extent that it can be visually confirmed. In addition, the effect is not recognized by single addition. To obtain the desired effects, 0.01% or more is required for each. If the addition amount is too large, the reason is not always clear, but rust locally concentrates on the edge of the steel sheet, etc.
Must be 0.15% and 0.2%.
【００１９】また、O が多い場合は、鋼板表面に存在す
る酸化物が増加する。この酸化物を起点とする錆の生成
を抑制するために、NiおよびCrの合計添加量をO 量に応
じた量とする必要がある。図１にNi+Cr 量、O 量と表面
むらの発生個数との関係を示している。図で示されるよ
うに、Ni+Cr 量はO 量に対して、［%O]≦0.002 ×[%Ni+
%Cr] ＋0.0018なる関係を満足させるようにする必要が
ある。なお、望ましくは、Ni+Cr:0.14%以下かつO :0.00
15%以下とすることにより表面むらの発生個数をさらに
減少することができる。When the amount of O 2 is large, the amount of oxides present on the surface of the steel sheet increases. In order to suppress the generation of rust originating from this oxide, the total amount of Ni and Cr needs to be adjusted according to the amount of O 2. FIG. 1 shows the relationship between the amount of Ni + Cr and the amount of O and the number of occurrences of surface unevenness. As shown in the figure, the amount of Ni + Cr is [% O] ≦ 0.002 × [% Ni +
% Cr] + 0.0018 must be satisfied. Incidentally, preferably, Ni + Cr: 0.14% or less and O: 0.00
By setting the content to 15% or less, the number of occurrences of surface unevenness can be further reduced.
【００２０】B は粒界偏析することにより、粒界の清浄
化を抑え、錆びの発生を抑制する。ただし、少なすぎる
とその効果が得られず、過剰に添加するとボライドを生
成し、逆に錆の起点となり表面性状を低下させる。図２
はB 量と鋼板の表面むらの発生個数との関係を示す図で
ある。図２で示されるように、表面むら個数の低減のた
めに、B は0.0002〜0.0009%とする必要がある。B suppresses the purification of the grain boundaries and the generation of rust by segregating at the grain boundaries. However, if the amount is too small, the effect cannot be obtained, and if it is added excessively, a boride is generated, and conversely, it becomes a starting point of rust and deteriorates surface properties. FIG.
FIG. 3 is a diagram showing the relationship between the B content and the number of occurrences of uneven surface of the steel sheet. As shown in FIG. 2, B needs to be 0.0002 to 0.0009% in order to reduce the number of uneven surfaces.
【００２１】C はその含有量が少ないほど成形性に有利
である。その量が0.003% を超えると目的とする成形性
を達成できない。したがって、C は0.003%以下にする必
要がある。The lower the content of C, the more advantageous the moldability. If the amount exceeds 0.003%, the desired formability cannot be achieved. Therefore, C needs to be less than 0.003%.
【００２２】Mnは錆の生成を助長する熱間圧延時の表面
割れの抑制に対して効果がある。しかし、Mnが0.05% 未
満ではその効果を発揮できない。また、2.2%を超える過
剰のMnは成形性を低下する。したがって、Mnは0.05〜2.
2%に限定する。Mn is effective in suppressing surface cracks during hot rolling, which promotes the formation of rust. However, if Mn is less than 0.05%, the effect cannot be exhibited. Further, an excessive amount of Mn exceeding 2.2% lowers moldability. Therefore, Mn is 0.05-2.
Limited to 2%.
【００２３】Siは材質上低い方が好ましく、その上限を
0.8%とする。 P は材質上低い方が好ましく、その上限を0.1%とする。The lower the material of Si is, the better.
0.8%. P is preferably lower in terms of material, and the upper limit is set to 0.1%.
【００２４】S は多すぎると錆の発生を助長させるの
で、少ない方がのぞましく、その上限を0.015%とする。If the content of S is too large, the generation of rust is promoted. Therefore, the content of S is preferably small, and the upper limit is made 0.015%.
【００２５】Alは溶鋼の脱酸のため添加する必要があ
る。その量が鋼中のsol.Alとして0.01% 未満ではその目
的が十分に達成できない。また、その量が0.1%を超える
と錆の起点となるアルミナが増加し、表面むらが増加す
る。したがって、sol.Alとして0.01〜0.1%に限定する。Al must be added for deoxidizing molten steel. If the amount is less than 0.01% as sol.Al in steel, the object cannot be sufficiently achieved. On the other hand, if the amount exceeds 0.1%, the amount of alumina serving as a starting point of rust increases, and the surface unevenness increases. Therefore, sol.Al is limited to 0.01 to 0.1%.
【００２６】N は成形性の点では低い方が望ましく、そ
の上限を0.003%とする。TiはC とN と固定し、成形性を
向上させる有用な元素である。その効果を発揮するため
には0.005%以上添加することが望ましい。また、0.12%
を超えて添加しても効果が飽和し、逆に経済性を損ね
る。したがって、Tiは0.005〜0.12%に限定する。N is desirably low in terms of moldability, and its upper limit is made 0.003%. Ti is a useful element that fixes C and N and improves formability. In order to exhibit the effect, it is desirable to add 0.005% or more. 0.12%
Even if added in excess, the effect is saturated and conversely impairs economic efficiency. Therefore, Ti is limited to 0.005 to 0.12%.
【００２７】以上を本発明の基本成分系とするが、成形
性向上のためにさらにNbを添加してもかまわない。Nbが
0.002%未満ではその目的を十分に達成できない。また、
0.02% を超えて添加すると成形性が低下する。したがっ
て、Nbは0.002〜0.02% に限定する。The above is the basic component system of the present invention, but Nb may be further added for improving moldability. Nb
If it is less than 0.002%, the purpose cannot be achieved sufficiently. Also,
If added in excess of 0.02%, the moldability will be reduced. Therefore, Nb is limited to 0.002 to 0.02%.
【００２８】なお、本発明が対象とする冷延鋼板は、通
常の冷延鋼板だけでなく、溶融めっき鋼板、電気めっき
鋼板、あるいはこれらの鋼板に有機複合皮膜、化成処理
などの処理を単独あるいは複合して施した表面処理鋼板
等を広く含むものである。The cold-rolled steel sheet to which the present invention is applied is not limited to a normal cold-rolled steel sheet, but may be a hot-dip coated steel sheet, an electroplated steel sheet, or any of these steel sheets, which may be subjected to a treatment such as an organic composite coating or a chemical conversion treatment. It broadly includes surface-treated steel sheets and the like which are applied in combination.
【００２９】また、本発明の効果は前記の鋼板のいずれ
においても得られる。上記化学成分を有する鋼板は、通
常は常法にしたがって転炉または電気炉で溶製、鋳造
し、熱間圧延を経て酸洗後冷間圧延により所望の板厚の
鋼板にされる。とくに限定するものではないが、加熱温
度を1150℃以上、仕上温度をAr3点以上として熱間圧延
を行い、さらに50%以上の圧下率を確保した冷間圧延す
ることで、本発明の効果は最大限に発揮される。なお、
熱間圧延時に再加熱を行わない直送圧延の場合でも本発
明の効果は損なわれない。The effect of the present invention can be obtained in any of the above steel sheets. The steel sheet having the above-mentioned chemical components is usually melted and cast in a converter or an electric furnace according to a conventional method, passed through hot rolling, pickled, and then cold-rolled into a steel sheet having a desired thickness. Although not particularly limited, the effect of the present invention is obtained by performing hot rolling at a heating temperature of 1150 ° C. or more and a finishing temperature of Ar 3 points or more, and further performing cold rolling with a reduction rate of 50% or more. Is maximized. In addition,
The effects of the present invention are not impaired even in the case of direct-feed rolling in which reheating is not performed during hot rolling.
【００３０】冷間圧延後の焼鈍は、箱焼鈍、連続焼鈍ラ
インあるいは連続溶融亜鉛めっきラインのいずれでもか
まわなし、後者の場合の合金化処理の有無は問わない。
また、焼鈍後調質圧延を経て，電気めっき、有機複合皮
膜あるいは化成処理などの表面処理を単独あるいは複合
して施した場合にも、本発明の効果は損なわれない。The annealing after the cold rolling may be any of box annealing, continuous annealing line, or continuous hot-dip galvanizing line. In the latter case, the presence or absence of alloying treatment is irrelevant.
Further, the effects of the present invention are not impaired even when surface treatment such as electroplating, organic composite coating or chemical conversion treatment is applied alone or in combination after temper rolling after annealing.
【００３１】[0031]
【実施例】表１にそれぞれ本発明鋼および比較鋼の組成
および最終製品段階での錆に起因する表面むら個数を示
す。EXAMPLES Table 1 shows the compositions of the steels of the present invention and the comparative steels and the number of surface irregularities caused by rust at the final product stage.
【００３２】[0032]
【表１】 [Table 1]
【００３３】基本的な製造条件として、連続鋳造スラブ
を熱間圧延−ランナウトテーブル上での冷却−巻き取り
処理により、2.8〜4.0mm板厚の熱延鋼板を得た。なお、
平均的な仕上げ温度は900℃、巻き取り温度は620℃であ
る。さらに酸洗後冷間圧延を行い(板厚0.6〜1.6mm)，78
0〜850℃の連続焼鈍−0.5%の調質圧延を施した（鋼1〜
6、13〜17、19〜23、28〜31）。なお、溶融亜鉛めっき
鋼板については、冷間圧延後820℃で連続焼鈍し、460℃
まで冷却した段階で片面あたり55g/m2の溶融亜鉛をめっ
きし、引き続き500℃で合金化処理を行い、1.0%の調質
圧延を行った（鋼7〜9、18、24 ）。一部について、さ
らに片面あたり3g/m2の80%Fe-Zn合金の上層電気亜鉛め
っきを施し、溶融めっき＋電気めっきの二層めっき鋼板
とした（鋼10、25）。電気めっき鋼板については、調質
圧延後、片面あたり30g/m2の88%Zn-Ni合金電気めっきを
行い( 鋼11、26) 、有機被覆鋼板については、電気めっ
きの上にさらにクロメート被覆50mg/m2(金属クロム換
算) 、樹脂層1μmの複合被覆を行った（鋼12、27）。
錆び発生の程度は、最終製品段階において、1m2当たり
に分布する直径2mm以上の表面むら個数によりを評価し
た。As a basic production condition, a hot-rolled steel sheet having a thickness of 2.8 to 4.0 mm was obtained by subjecting a continuously cast slab to hot rolling, cooling on a run-out table, and winding. In addition,
The average finishing temperature is 900 ° C and the winding temperature is 620 ° C. Further, after cold pickling, cold rolling was performed (sheet thickness 0.6 to 1.6 mm).
Continuous annealing at 0-850 ° C-Temper rolling of 0.5% (steel 1-
6, 13-17, 19-23, 28-31). The hot-dip galvanized steel sheet was continuously annealed at 820 ° C after cold rolling to 460 ° C.
At the stage of cooling to about 55 g / m 2 per side, hot-dip zinc was plated, followed by alloying at 500 ° C. and temper rolling of 1.0% (steels 7 to 9, 18, and 24). Some parts were further subjected to upper electrogalvanizing of 80% Fe-Zn alloy of 3 g / m 2 per one side to obtain hot-dip + electroplating double-layered steel sheets (steel 10, 25). The electroplated steel sheet, temper after rolling, subjected to 88% Zn-Ni alloy electroplating in per side 30 g / m 2 (steel 11, 26), for the organic coated steel sheet, chromate coating 50mg over the electroplating / m 2 (converted to chromium metal) and a resin layer of 1 μm was coated (Steel 12, 27).
The degree of rust generation was evaluated based on the number of uneven surfaces having a diameter of 2 mm or more distributed per 1 m 2 at the final product stage.
【００３４】比較鋼のNi、Cr添加量が適正でない鋼20〜
24は表面むら個数が3.2〜5.3個/m2、Ni、Crが複合添加
でない鋼28、29は5.8〜6.3個/m2、O 量が適正でない鋼1
9、25〜27は2.2〜18.1個/m2、B 量が適正でない鋼30、3
1は1.6個/m2以上であるのに対し、本発明鋼1〜18は0.8
個/m2以下となっている。とくに、0：0.0015%以下でCr+
Ni：0.02〜0.14%のものは0.4%個/m2以下と低くなってい
る。Steels of Comparative Steels with Inappropriate Ni and Cr Additions
24 surface unevenness number is 3.2 to 5.3 pieces / m 2, Ni, steel 1 Cr is steel 29 not combined addition is not appropriate is from 5.8 to 6.3 pieces / m 2, O weight
9, 25 to 27: 2.2 to 18.1 pieces / m 2 , steel with inappropriate B content 30, 3
1 whereas it is 1.6 pieces / m 2 or more, the present invention steels 1 to 18 0.8
Pieces / m 2 or less. In particular, 0: Cr + at 0.0015% or less
Ni: 0.02 to 0.14% is as low as 0.4% / m 2 or less.
【００３５】[0035]
【発明の効果】以上のごとく本発明によれば、極低炭素
鋼板で問題となる錆に起因する表面むらが新たな設備の
設置あるいは製造プロセスの変更をすることなく低減で
き、表面性状に優れた冷延鋼板を得ることができる。As described above, according to the present invention, surface unevenness due to rust, which is a problem in ultra-low carbon steel sheets, can be reduced without installing new equipment or changing the manufacturing process, and the surface properties are excellent. Cold rolled steel sheet can be obtained.
【図１】O 量、Ni+Cr量と表面むら個数との関係を示す
図である。FIG. 1 is a diagram showing the relationship between the amount of O, the amount of Ni + Cr, and the number of uneven surfaces.
【図２】B 量と表面むら個数との関係を示す図である。FIG. 2 is a diagram showing the relationship between the amount of B and the number of uneven surfaces.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 中村 清治 東京都千代田区丸の内一丁目１番２号 日本鋼管株式会社内 (56)参考文献 特開 平６−25754（ＪＰ，Ａ) 特開 平４−235250（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) C22C 38/00 301 C22C 38/54 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Seiji Nakamura 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Inside Nippon Kokan Co., Ltd. (56) References JP-A-6-25754 (JP, A) JP-A-4 −235250 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) C22C 38/00 301 C22C 38/54
Claims (2)
%、Si:0.8%以下、P:0.1%以下、S:0.015%以下、sol.Al:
0.01〜0.1%、N:0.003%以下、Ti:0.005〜0.12%、B:0.000
2〜0.0009%、Ni:0.01〜0.15%、Cr:0.01〜0.2%、O:0.000
2%以上を含み、かつ前記のNi、Cr、O が、［%O]≦0.002
×[%Ni+%Cr] ＋0.0018なる関係を満足し、残部鉄およ
び不可避的不純物からなる表面性状に優れた冷延鋼板。(1) C: 0.003% or less, Mn: 0.05 to 2.2% by weight
%, Si: 0.8% or less, P: 0.1% or less, S: 0.015% or less, sol.Al:
0.01 to 0.1%, N: 0.003% or less, Ti: 0.005 to 0.12%, B: 0.000
2 to 0.0009%, Ni: 0.01 to 0.15%, Cr: 0.01 to 0.2%, O: 0.000
2% or more, and the above-mentioned Ni, Cr, O 2 is [% O] ≦ 0.002
× [% Ni +% Cr] +0.0018, cold-rolled steel sheet with excellent surface properties consisting of iron and unavoidable impurities.
%、Si:0.8%以下、P:0.1%以下、S:0.015%以下、sol.Al:
0.01〜0.1%、N:0.003%以下、Ti:0.005〜0.12%、B:0.000
2〜0.0009%、Ni:0.01〜0.15%、Cr:0.01〜0.2%、O:0.000
2%以上を含み、かつ前記のNi、Cr、O が、［%O]≦0.002
× [%Ni+%Cr]＋0.0018なる関係を満足し、さらに、Nb:
0.002〜0.02%を含み、残部鉄および不可避的不純物から
なる表面性状に優れた冷延鋼板。2. C: 0.003% or less, Mn: 0.05 to 2.2% by weight
%, Si: 0.8% or less, P: 0.1% or less, S: 0.015% or less, sol.Al:
0.01 to 0.1%, N: 0.003% or less, Ti: 0.005 to 0.12%, B: 0.000
2 to 0.0009%, Ni: 0.01 to 0.15%, Cr: 0.01 to 0.2%, O: 0.000
2% or more, and the above-mentioned Ni, Cr, O 2 is [% O] ≦ 0.002
× [% Ni +% Cr] +0.0018, and Nb:
Cold rolled steel sheet containing 0.002 to 0.02%, with excellent surface properties consisting of balance iron and unavoidable impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06180044A JP3114507B2 (en) | 1994-08-01 | 1994-08-01 | Cold rolled steel sheet with excellent surface properties |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06180044A JP3114507B2 (en) | 1994-08-01 | 1994-08-01 | Cold rolled steel sheet with excellent surface properties |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0841584A JPH0841584A (en) | 1996-02-13 |
| JP3114507B2 true JP3114507B2 (en) | 2000-12-04 |
Family
ID=16076511
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP06180044A Expired - Fee Related JP3114507B2 (en) | 1994-08-01 | 1994-08-01 | Cold rolled steel sheet with excellent surface properties |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3114507B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW200932926A (en) * | 2007-04-11 | 2009-08-01 | Nippon Steel Corp | Hot-dip metal coated high-strength steel sheet for press working excellent in low-temperature toughness and process for production thereof |
| JP5176484B2 (en) * | 2007-10-30 | 2013-04-03 | 新日鐵住金株式会社 | Alloyed hot-dip galvanized steel sheet with excellent appearance |
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- 1994-08-01 JP JP06180044A patent/JP3114507B2/en not_active Expired - Fee Related
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| Publication number | Publication date |
|---|---|
| JPH0841584A (en) | 1996-02-13 |
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