JP2009249714A - Method for producing hot-rolled steel sheet excellent in surface-processing property - Google Patents

Method for producing hot-rolled steel sheet excellent in surface-processing property Download PDF

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JP2009249714A
JP2009249714A JP2008101835A JP2008101835A JP2009249714A JP 2009249714 A JP2009249714 A JP 2009249714A JP 2008101835 A JP2008101835 A JP 2008101835A JP 2008101835 A JP2008101835 A JP 2008101835A JP 2009249714 A JP2009249714 A JP 2009249714A
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steel sheet
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rolled steel
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JP4901799B2 (en
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Teruki Hayashida
輝樹 林田
Takahiro Katai
崇博 片井
Shigenori Yakura
重範 矢倉
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Nippon Steel Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a hot-rolled steel sheet excellent in a surface-processing property without generating uneven adhesive-state of the surface-processing material. <P>SOLUTION: The steel sheet is produced through the following processes: a heating process for heating a slab having the steel composition composed by mass% of 0.001-0.05% C, 0.001-0.2% Si, 0.01-0.4% Mn, 0.001-0.1% P, 0.001-0.02% S, 0.005-0.09% Al, 0.001-0.015% N, 0.002-0.1% Ni and the balance Fe with inevitable impurities to the temperature of ≥1,150°C; a coiling process for winding at the coiling temperature of 700-850°C to the hot-rolled steel sheet obtained by applying the hot-rolling to the heated slab; a cold-rolling process for cold-rolling to the coiled hot-rolled sheet at 1-2.5% cold-rolling ratio; and a pickling process for pickling the hot-rolled steel sheet applying the cold-rolling at pickling temperature of 85-95°C for pickling time of 45-120sec with pickling solution having 10-15 mass% HCl concentration. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、自動車等のように表面の美麗さが要求される用途に好適な熱延鋼板の製造方法に関する。   The present invention relates to a method for producing a hot-rolled steel sheet suitable for applications that require a beautiful surface, such as an automobile.

熱延鋼板の表面にはスケールが付着しているため、熱延鋼板を冷間圧延する場合にはスケールを除去する必要がある。スケールを除去する手段として、一般的に酸洗処理が行われるが、特に冷間圧延後の電着塗装の前処理である化成処理性の向上や、メッキ工程で美麗な外観とする目的のためには、表面のスケールを完全に除去することが必要となる。   Since the scale adheres to the surface of the hot-rolled steel sheet, it is necessary to remove the scale when the hot-rolled steel sheet is cold-rolled. As a means for removing scales, pickling is generally performed. Especially for the purpose of improving chemical conversion treatment, which is a pretreatment of electrodeposition coating after cold rolling, and providing a beautiful appearance in the plating process. For this, it is necessary to completely remove the scale of the surface.

そのために、例えば特許文献１に開示されているように、冷延加工、酸洗、ブラシ研磨等の各処理を組み合わせることにより、脱スケール処理を施す技術が提案されている。また、特許文献２には、圧延機で圧下率０．１％〜２０％の圧延を行うことにより、熱延鋼板表面のスケールを破砕した後に酸洗を行う技術が提案されている。   Therefore, as disclosed in Patent Document 1, for example, a technique for performing a descaling process by combining various processes such as cold rolling, pickling, and brush polishing has been proposed. Patent Document 2 proposes a technique of pickling after crushing the scale on the surface of a hot-rolled steel sheet by rolling with a rolling mill at a reduction rate of 0.1% to 20%.

これらの手段により、表面外観上はスケールが除去された美麗な表面状態となる。しかしながら、このようにして酸洗した鋼板を冷間圧延した後、化成処理を行うと表面処理物質の付着ムラを生じてしまうことがあった。   By these means, the surface appearance becomes a beautiful surface state from which scale has been removed. However, when the steel plate thus pickled is cold-rolled and then subjected to a chemical conversion treatment, uneven adhesion of the surface treatment material may occur.

これらの原因は、Ｆｅよりも酸化されにくいＮｉやＣｕ等の元素が酸化スケールの生成に伴って地鉄の表層部に不均一に濃化することであると考えられる。これを解決するために、例えば特許文献３では、熱延鋼板を酸洗してスケール除去した後、さらにインヒビタを添加しない最終酸洗によってさらに鋼板表層を溶解する技術が提案されている。
特開平１１−１５６４２７号公報 特開昭６１−１４４２１３号公報 特開２００５−２８１７７５号公報 These causes are thought to be due to the non-uniform concentration of elements such as Ni and Cu, which are less oxidized than Fe, in the surface layer portion of the base iron as the oxide scale is generated. In order to solve this, for example, Patent Document 3 proposes a technique in which a hot-rolled steel sheet is pickled and scale removed, and then the steel sheet surface layer is further dissolved by final pickling without adding an inhibitor.
JP-A-11-156427 JP 61-144213 A JP 2005-281775 A

しかしながら、特許文献３に開示された方法では、酸洗を２回行うことが必要であり、処理コストが高くなるという問題がある。また、Ｎｉなどの濃化の影響は解消できるものの、依然として表面処理物質の付着むらが発生してしまう場合があった。   However, in the method disclosed in Patent Document 3, it is necessary to perform pickling twice, and there is a problem that the processing cost becomes high. In addition, although the influence of concentration of Ni or the like can be eliminated, uneven adhesion of the surface treatment substance may still occur.

本発明は、上述した問題点に鑑みて案出されたものであり、表面処理物質の付着むらが生じない表面処理性に優れた熱延鋼板の製造方法を提供することを目的とする。   The present invention has been devised in view of the above-described problems, and an object of the present invention is to provide a method for producing a hot-rolled steel sheet having excellent surface treatment properties that does not cause uneven adhesion of a surface treatment substance.

請求項１記載の発明は、質量％で、Ｃ：０．００１〜０．０５％、Ｓｉ：０．００１〜０．２％、Ｍｎ：０．０１〜０．４％、Ｐ：０．００１〜０．１％、Ｓ：０．００１〜０．０２％、Ａｌ：０．００５〜０．０９％、Ｎ：０．００１〜０．０１５％、Ｎｉ：０．００２〜０．１％を含有し、残部が鉄および不可避的不純物からなる鋼組成のスラブを１１５０℃以上の温度に加熱する工程と、前記加熱したスラブに対して熱間圧延を施すことにより得られた熱延鋼板を７００℃〜８５０℃の巻取温度で巻き取る工程と、前記巻き取った熱延鋼板を冷間加工率１〜２．５％で冷間圧延する工程と、前記冷間圧延した熱延鋼板を、ＨＣｌ濃度１０〜１５質量％である酸洗液により酸洗温度８５〜９５℃、酸洗時間４５〜１２０秒で酸洗する工程とを有することを特徴とする。   Invention of Claim 1 is the mass%, C: 0.001-0.05%, Si: 0.001-0.2%, Mn: 0.01-0.4%, P: 0.001 -0.1%, S: 0.001-0.02%, Al: 0.005-0.09%, N: 0.001-0.015%, Ni: 0.002-0.1% A step of heating a steel composition slab containing iron and inevitable impurities to a temperature of 1150 ° C. or higher, and a hot rolled steel sheet obtained by hot rolling the heated slab 700 A step of winding at a coiling temperature of 850C to 850C, a step of cold rolling the rolled hot-rolled steel sheet at a cold working rate of 1 to 2.5%, and the cold-rolled hot-rolled steel sheet, Pickling with a pickling solution having an HCl concentration of 10 to 15% by mass at a pickling temperature of 85 to 95 ° C. and a pickling time of 45 to 120 seconds. Characterized in that it has a.

請求項２記載の発明は、請求項１記載の発明において、前記スラブは、更に質量％で、Ｃｒ：０．５％以下、Ｃｕ：０．５％以下、Ｔｉ：０．１％以下、Ｎｂ：０．０５％以下、Ｖ：０．０５％以下、Ｍｏ：０．０５％以下、Ｃａ：０．００５％以下、Ｂ：０．００５％以下の１種または２種以上を、さらに含有することを特徴とする。   The invention according to claim 2 is the invention according to claim 1, wherein the slab is further in mass%, Cr: 0.5% or less, Cu: 0.5% or less, Ti: 0.1% or less, Nb : 0.05% or less, V: 0.05% or less, Mo: 0.05% or less, Ca: 0.005% or less, B: 0.005% or less It is characterized by that.

本発明によれば、肉眼で観察することができるスケールを除去することができることに加え、鋼板表面におけるＦｅ以外の元素の濃化部を除去することが可能となり、電着塗装の前処理である化成処理で表面への付着性が悪化してしまうのを防止することや、鋼板表面においてムラが生じない均一なメッキを施すことが可能となる。   According to the present invention, in addition to being able to remove the scale that can be observed with the naked eye, it is possible to remove the concentrated portion of elements other than Fe on the steel sheet surface, which is a pretreatment for electrodeposition coating. It is possible to prevent the adhesion to the surface from being deteriorated by the chemical conversion treatment, and to perform uniform plating that does not cause unevenness on the surface of the steel sheet.

以下、本発明を実施するための最良の形態について、詳細に説明する。以下、組成における質量％は、単に％と記載する。   Hereinafter, the best mode for carrying out the present invention will be described in detail. Hereinafter, the mass% in the composition is simply described as%.

本発明者らは、化成処理やメッキなどの表面処理物質の付着ムラの原因を明らかにするために、従来の方法で酸洗した熱延鋼板および化成処理ムラを生じた鋼板を詳細に調査した。その結果、酸洗後の鋼板表面には、従来言われていたＮｉ以外にＰの濃化が見られ、それも表面処理物質の付着ムラの原因となっていることを見出した。さらに、ＭｎＳなどの粗大な析出物が表面に露出している場合に、付着ムラの原因になっていることを見出した。   In order to clarify the cause of adhesion unevenness of a surface treatment substance such as chemical conversion treatment or plating, the present inventors have investigated in detail the hot-rolled steel sheet pickled by a conventional method and the steel sheet that has undergone chemical conversion treatment unevenness. . As a result, it was found that the steel sheet surface after pickling was enriched with P in addition to the conventionally-known Ni, which also caused uneven adhesion of the surface treatment substance. Furthermore, it has been found that when coarse precipitates such as MnS are exposed on the surface, they cause adhesion unevenness.

そこで本発明者らは、上述した表面処理物質の付着ムラの原因を解消するための条件について検討した。ＭｎＳの粗大な析出物は、鋼板表面に濃化して存在しているわけではなく、鋼板中にほぼランダムに存在しているが、鋼板表面に露出した場合に表面処理物質の付着ムラの原因となる。したがってこれら粗大な析出物の生成を抑制することが必要となるが、そのためには、ＭｎとＳの濃度を調整するとともに、スラブの加熱時に固溶させることが有効であることを見出した。   Therefore, the present inventors examined conditions for eliminating the cause of uneven adhesion of the surface treatment substance described above. The coarse precipitates of MnS are not concentrated and present on the steel sheet surface, but are present almost randomly in the steel sheet. Become. Therefore, it is necessary to suppress the formation of these coarse precipitates. For this purpose, it has been found that it is effective to adjust the concentrations of Mn and S and to dissolve the slab during heating.

Ｐは酸化されてスケール中に取り込まれやすいが、表面処理物質の付着性への影響が大きく、わずかに濃化部が残存するだけでも付着ムラの原因となってしまうことがわかった。したがってＰの濃化をできるだけ抑制することが必要となるが、熱延後の巻き取り温度を高くすることで、表面近傍のＰを酸化させ、スケールに取り込まれるのを助長することができ、地鉄表面のＰ濃度を低減させることができることを見出した。   Although P is easily oxidized and taken into the scale, it has been found that it has a great influence on the adhesion of the surface treatment substance, and even if a slightly concentrated portion remains, it causes adhesion unevenness. Therefore, it is necessary to suppress the P concentration as much as possible, but by increasing the coiling temperature after hot rolling, it is possible to oxidize P in the vicinity of the surface and promote the incorporation into the scale. It has been found that the P concentration on the iron surface can be reduced.

またＮｉ等の酸化しにくい元素は、熱延後の巻き取り温度を高くしても鋼板表面において濃化させたまま残存することになるが、一度巻き取った熱延鋼板に対して冷間圧延を施した後に酸洗することにより、これらＮｉ等の元素を地鉄と同時に酸に溶解させて除去し、ひいてはＮｉの如き元素を鋼板表面からできるだけ低減させることができることを見出した。   Further, elements that are difficult to oxidize, such as Ni, will remain concentrated on the surface of the steel sheet even if the coiling temperature after hot rolling is increased, but cold rolling is applied to the hot-rolled steel sheet once wound. It was found that the elements such as Ni can be removed by dissolving them in the acid simultaneously with the base iron by pickling after applying the iron, and as a result, the elements such as Ni can be reduced as much as possible from the surface of the steel sheet.

次に、鋼組成の成分を限定した理由について説明をする。   Next, the reason for limiting the components of the steel composition will be described.

Ｃ：０．００１〜０．０５％
Ｃは、鋼板の強度を確保するために必要な元素である。しかしながら、このＣ含有量が０．００１％未満では、高い強度の要求に応えることができない。これに対して、Ｃ含有量が０．０５％を超えると、熱間圧延の過程において発生するスケールの部分的な厚みが不均一となり、酸洗後の部分的なスケールの残存により、均一な表面処理が実現できなくなる。このため、上限を０．０５％としている。 C: 0.001 to 0.05%
C is an element necessary for ensuring the strength of the steel sheet. However, when the C content is less than 0.001%, it is not possible to meet the demand for high strength. On the other hand, if the C content exceeds 0.05%, the partial thickness of the scale generated in the process of hot rolling becomes non-uniform, and the residual partial scale after pickling is uniform. Surface treatment cannot be realized. For this reason, the upper limit is made 0.05%.

Ｓｉ：０．００１〜０．２％
Ｓｉは、固溶強化元素として、延性を低下させることなく強度の上昇に寄与する。Ｓｉは、鋳造段階において鋼板中のＦｅとともに酸化されたフェライトが、熱延、酸洗後においても鋼板表面に残存してしまう場合もあり、また固溶状態で鋼板表面に濃化してしまう場合がある。酸化したＳｉが鋼板表面近傍において濃化すると、即ち、このＳｉ含有量が０．２％を超えると、酸洗の際に、スケールが充分に除去されず残存しやすくなり、微量に残存するスケールによって表面処理性が低下するため、その量は少ないほうが好ましい。このため、Ｓｉの上限を０．２％とした。またＳｉ含有量が０．００１未満では、固溶強化の効果が得られないことから、下限を０．００１％としている。 Si: 0.001 to 0.2%
Si, as a solid solution strengthening element, contributes to an increase in strength without reducing ductility. Si may be oxidized in the casting stage together with Fe in the steel sheet, and may remain on the steel sheet surface even after hot rolling and pickling, or may be concentrated on the steel sheet surface in a solid solution state. is there. When oxidized Si is concentrated in the vicinity of the steel sheet surface, that is, when the Si content exceeds 0.2%, the scale tends to remain without being sufficiently removed during pickling, and the scale remains in a trace amount. Since the surface treatment property is lowered by this, the amount is preferably smaller. For this reason, the upper limit of Si was 0.2%. Further, when the Si content is less than 0.001, the effect of solid solution strengthening cannot be obtained, so the lower limit is made 0.001%.

Ｍｎ：０．０１〜０．４％
Ｍｎは、鋼板の強度を確保すると共に、鋼中のＳに起因する熱間圧延時の割れを防止する効果がある。Ｍｎを添加することにより生成するＭｎＳ自体は、表面濃化することなく、ほぼランダムに分布する。しかしながら、生成するＭｎＳのサイズが大きい場合には、これが表面に露出すると、化成処理やメッキを施す上でのムラとなりやすい。このため、生成されるＭｎＳのサイズは０．５μｍ以下とすることが好ましく、そのためには、Ｍｎの上限を０．４％としている。なお、Ｍｎ含有量が０．０１％未満である場合には、熱間圧延時の割れを防止することができず、外観性状が低下してしまう。このため、Ｍｎの下限を０．０１％としている。 Mn: 0.01 to 0.4%
Mn has the effect of ensuring the strength of the steel sheet and preventing cracking during hot rolling due to S in the steel. MnS itself produced by adding Mn is distributed almost randomly without surface concentration. However, when the size of MnS to be generated is large, if it is exposed on the surface, it tends to be uneven in performing chemical conversion treatment or plating. For this reason, it is preferable that the size of MnS to be generated is 0.5 μm or less, and for that purpose, the upper limit of Mn is set to 0.4%. In addition, when Mn content is less than 0.01%, the crack at the time of hot rolling cannot be prevented, but an external appearance property will fall. For this reason, the lower limit of Mn is set to 0.01%.

Ｐ：０．００１〜０．１％
Ｐは、不純物として鋼中に不可避的に含有される元素である。このＰ含有量が０．１％を超えると、熱延後の巻き取り温度を高くしても、局部的な偏析が発生して鋼板表面にスジ状模様が形成され、外観性状が低下し、表面処理性が低下してしまう。このため、Ｐの上限を０．１％としている。また、Ｐ含有量を０．００１未満とするには、製造コストが上昇してしまい好ましくない。このため、Ｐの下限を０．００１％としている。 P: 0.001 to 0.1%
P is an element inevitably contained in steel as an impurity. If this P content exceeds 0.1%, even if the coiling temperature after hot rolling is increased, local segregation occurs and streaky patterns are formed on the steel sheet surface, and the appearance properties are reduced. Surface treatment property will fall. For this reason, the upper limit of P is set to 0.1%. On the other hand, if the P content is less than 0.001, the manufacturing cost increases, which is not preferable. For this reason, the lower limit of P is set to 0.001%.

Ｓ：０．００１〜０．０２％
Ｓは、Ｐと同様に不純物として含有される元素であり、鋼中でＭｎＳを形成し、切削性を向上させる有用元素である。しかしながら、上述したように生成されるＭｎＳのサイズが大きい場合には、これが表面に露出すると、化成処理やメッキを施す上でのムラとなりやすい。このため、生成されるＭｎＳのサイズを０．５μｍ以下とするために、Ｓの上限を０．０２％としている。これに対して、このＳ含有量を０．００１未満とするには、製造コストが上昇してしまい好ましくないため、下限を０．００１％としている。 S: 0.001 to 0.02%
S is an element that is contained as an impurity in the same manner as P, and is a useful element that forms MnS in steel and improves machinability. However, when the size of MnS produced as described above is large, if it is exposed on the surface, it tends to cause unevenness in chemical conversion treatment or plating. For this reason, in order to make the size of MnS produced | generated into 0.5 micrometer or less, the upper limit of S is made into 0.02%. On the other hand, if the S content is less than 0.001, it is not preferable because the manufacturing cost increases, so the lower limit is made 0.001%.

Ａｌ：０．００５〜０．０９％
Ａｌは、鋼を製造する上での脱酸元素として必要であり、Ｎによる延性低下を防止して鋼板の加工性を確保するために使用される。このＡｌが０．００５％未満では上述した効果を十分に発揮することができず０．０３％以上が好ましい。また、Ａｌが０．０９％を超えると上述した効果が飽和してしまう。このため、Ａｌ含有量は、０．００５〜０．０９％とする。 Al: 0.005 to 0.09%
Al is necessary as a deoxidizing element for producing steel, and is used for preventing ductility deterioration due to N and ensuring the workability of the steel sheet. If the Al content is less than 0.005%, the above-described effects cannot be exhibited sufficiently, and 0.03% or more is preferable. Moreover, when Al exceeds 0.09%, the effect mentioned above will be saturated. For this reason, Al content shall be 0.005-0.09%.

Ｎ：０．００１〜０．０１５％
Ｎは、溶鋼処理中に空気中の窒素が取り込まれることから、鋼中に不可避的に混入する元素である。このＮは、鋼板の延性低下原因となるため、少ないほうが望ましい。ちなみに、このＮは、強化元素としても有効である。Ｎは、ＡｌやＢ等と窒化物を形成して母材組織の細粒化を促進し、ひいては鋼板の加工性の向上にも寄与する。しかしながら、このＮ含有量が０．０１５％を超えると延性低下が著しくなるため、０．０１５％を上限としている。また、Ｎ含有量が０．００１未満では、鋼板の結晶粒が局部的に異常成長を起こす場合があり、その場合は局部的に強度が低下する等のデメリットがある。また、このＮが０．０１５％を超えると、鋼板の延性低下が著しくなる。このため、Ｎ含有量は、０．００１〜０．０１５％とする。 N: 0.001 to 0.015%
N is an element that is inevitably mixed in steel because nitrogen in the air is taken in during the treatment of molten steel. Since this N causes the ductility fall of a steel plate, the one where it is smaller is desirable. Incidentally, this N is also effective as a strengthening element. N forms nitrides with Al, B, etc., and promotes the refinement of the base material structure, thereby contributing to the improvement of the workability of the steel sheet. However, if the N content exceeds 0.015%, the ductility decreases significantly, so 0.015% is made the upper limit. Moreover, if N content is less than 0.001, the crystal grain of a steel plate may raise abnormally locally, and there exists a demerit, such as intensity | strength falling locally in that case. Moreover, when this N exceeds 0.015%, the ductility fall of a steel plate will become remarkable. For this reason, N content shall be 0.001-0.015%.

Ｎｉ：０．００２〜０．１％
Ｎｉは、スケールの均一性を確保する機能を発揮する元素である。このＮｉが０．００２％未満では上述した効果を十分に発揮することができない。０．１％を超えると鋼板表面に局所的に濃化して表面処理性が低下してしまうため、０．１％を上限としている。 Ni: 0.002 to 0.1%
Ni is an element that exhibits the function of ensuring the uniformity of the scale. If the Ni content is less than 0.002%, the above-described effects cannot be exhibited sufficiently. If it exceeds 0.1%, the steel sheet is locally concentrated on the steel sheet surface and the surface treatment property is lowered, so 0.1% is made the upper limit.

Ｃｒ：０．５％以下
Ｃｒは、強度上昇に有効であり、耐食性を向上させるためにも必要に応じて添加するが、０．５％を超えると表面性状が低下して表面処理性が悪化するため、上限を０．５％としている。 Cr: 0.5% or less Cr is effective in increasing the strength and is added as necessary to improve the corrosion resistance. However, if it exceeds 0.5%, the surface properties are lowered and the surface treatment property is deteriorated. Therefore, the upper limit is set to 0.5%.

Ｃｕ：０．５％以下
Ｃｕは、鋼板の強度上昇とともに、スケールの密着度を向上させる効果がある。このＣｕが０．５％を超えると熱延における鋼板表面の荒れが発生して表面処理性が低下してしまうため、上限を０．５％としている。 Cu: 0.5% or less Cu has an effect of improving the degree of adhesion of the scale as the strength of the steel sheet increases. If this Cu exceeds 0.5%, the surface of the steel sheet is roughened by hot rolling and the surface treatment property is lowered, so the upper limit is made 0.5%.

Ｔｉ：０．１％以下
Ｔｉは、Ｃ，Ｎとの親和力が強く、凝固時にＴｉＣ、ＴｉＮとして析出して、Ｃ，Ｎによる延性低下を防止するために用いられる。しかしながら、このＴｉが０．１％を超えるとその効果が飽和するため、上限を０．１％としている。 Ti: 0.1% or less Ti has a strong affinity for C and N, and precipitates as TiC and TiN at the time of solidification, and is used to prevent ductility deterioration due to C and N. However, if this Ti exceeds 0.1%, the effect is saturated, so the upper limit is made 0.1%.

Ｎｂ：０．０５％以下
Ｎｂは、組織の微細粒化により靭性を向上させる。Ｎｂは、Ｎによる延性低下を防止する役割も果たすが、Ｎｂ含有量０．０５％を超えるとその効果が飽和する。このため、Ｎｂの上限を０．０５％としている。 Nb: 0.05% or less Nb improves toughness by making the structure finer. Nb also plays the role of preventing ductility deterioration due to N, but its effect is saturated when the Nb content exceeds 0.05%. For this reason, the upper limit of Nb is set to 0.05%.

Ｖ：０．０５％以下
Ｖは、母材の強度を増加させるとともに靭性を向上させる元素である。しかしながら、このＶ含有量が０．０５％を超えると、その効果が飽和してしまう。このため、Ｖの上限を０．０５％としている。 V: 0.05% or less V is an element that increases the strength of the base material and improves the toughness. However, when the V content exceeds 0.05%, the effect is saturated. For this reason, the upper limit of V is set to 0.05%.

Ｍｏ：０．０５％以下
Ｍｏは、鋼の強度向上に有用なだけでなく、靭性も大幅に向上させる。しかし、このＭｏ含有量が０．０５％を超えるとその効果は飽和するため、上限を０．０５％としている。 Mo: 0.05% or less Mo is not only useful for improving the strength of steel, but also greatly improves toughness. However, when the Mo content exceeds 0.05%, the effect is saturated, so the upper limit is made 0.05%.

Ｃａ：０．００５％以下
Ｃａは、ＭｎＳ生成による鋼板の強度低下を防止するために添加されるが、Ｃａ添加量が０．００５％を超えるとその効果が飽和するため、上限を０．００５％としている。 Ca: 0.005% or less Ca is added in order to prevent a reduction in strength of the steel sheet due to MnS generation. However, when the Ca addition amount exceeds 0.005%, the effect is saturated, so the upper limit is set to 0.005. %.

Ｂ：０．００５％以下
Ｂは、ＮをＢＮとして固着する作用もあることから、Ｎによる鋼板の延性低下を防止する役割を果たすとともに、ロウ付け強度を向上させる作用もある。しかしながら、このＢ含有量が０．００５％を超えるとその効果が飽和してしまうため、上限を０．００５％としている。 B: 0.005% or less B has an effect of fixing N as BN, and thus has a function of preventing the ductility of the steel sheet from being lowered by N and also improves the brazing strength. However, if this B content exceeds 0.005%, the effect is saturated, so the upper limit is made 0.005%.

次に、本発明を適用した熱延鋼板の製造方法の条件について詳細に説明する。   Next, the conditions of the manufacturing method of the hot rolled steel sheet to which the present invention is applied will be described in detail.

先ず上述した鋼構成からなるスラブを加熱炉において１１５０℃以上の温度で加熱をする。この加熱温度が１１５０℃以上とする理由としては、ＭｎＳを鋼板内部に一度固溶させるためである。また、加熱温度が１２５０℃を超えると、結晶粒径が大きくなり過ぎて、必要な材質が得られなくなる場合があるので、１２５０℃以下であることが好ましい。   First, a slab having the above-described steel structure is heated at a temperature of 1150 ° C. or higher in a heating furnace. The reason for setting the heating temperature to 1150 ° C. or higher is that MnS is once dissolved in the steel sheet. In addition, if the heating temperature exceeds 1250 ° C, the crystal grain size becomes too large and a necessary material may not be obtained.

次に、この加熱したスラブを粗圧延機、仕上げ圧延機により熱間圧延し、冷却装置により冷却して巻取機により巻き取る。この巻き取る際の巻取温度は、７００℃〜８５０℃の範囲とする。巻取温度が７００℃未満では、Ｐの酸化を促進させることができず、固溶して残存するＰの表面付近の濃度が却って向上してしまう。巻取温度が７００℃以上とすることにより、鋼板表面におけるＰの酸化を促進させるとともに、固溶して残存するＰを地鉄側に引き込み、鋼板表面近傍におけるＰ濃度を低減させることが可能となる。   Next, this heated slab is hot-rolled by a roughing mill and a finish rolling mill, cooled by a cooling device, and wound by a winder. The winding temperature at the time of winding is in the range of 700 ° C to 850 ° C. If the coiling temperature is less than 700 ° C., the oxidation of P cannot be promoted, and the concentration in the vicinity of the surface of P remaining in solid solution will be improved. When the coiling temperature is set to 700 ° C. or higher, the oxidation of P on the steel sheet surface is promoted, and the solid solution and the remaining P can be drawn to the ground iron side, thereby reducing the P concentration in the vicinity of the steel sheet surface. Become.

また、巻取温度が８５０℃を超えると、熱延鋼板の結晶粒が大きくなりすぎ、強度が低下してしまうため、上限を８５０℃に規定する。   On the other hand, if the coiling temperature exceeds 850 ° C., the crystal grains of the hot-rolled steel sheet become too large and the strength decreases, so the upper limit is defined as 850 ° C.

次に、この巻き取った熱延鋼板を、冷間圧延機により、冷間加工率１％以上で冷間圧延する。この冷間加工を施すことにより、熱延鋼板表面のスケールに微細なクラックを多数導入することが可能となる。その結果、酸洗におけるＨＣｌ水溶液を鋼板表面からクラックを通じて奥深く浸透させることができ、酸洗により熱延鋼板を表面からより深く溶解することが可能となる。冷間加工率が１％未満では微小亀裂を導入するために不十分である。また、冷間加工率が２．５％を超える場合には、必要以上に多数のクラックが発生してしまい、またクラックの深さも深くなり、不均一に溶解されたりピット状に溶解され表面外観が損なわれる場合がある。このため、冷間加工率は、１〜２．５％の範囲としている。   Next, the wound hot-rolled steel sheet is cold-rolled with a cold rolling mill at a cold working rate of 1% or more. By performing this cold working, it becomes possible to introduce many fine cracks in the scale of the surface of the hot rolled steel sheet. As a result, the aqueous HCl solution in the pickling can penetrate deeply through the cracks from the steel sheet surface, and the hot-rolled steel sheet can be dissolved deeper from the surface by pickling. If the cold work rate is less than 1%, it is insufficient for introducing microcracks. If the cold working rate exceeds 2.5%, more cracks will be generated than necessary, and the depth of the cracks will be deeper. May be damaged. For this reason, the cold working rate is in the range of 1 to 2.5%.

なお、ここでいう冷間加工率とは、冷間加工する前の熱延鋼板の板厚をＤ、また冷間加工による減厚量をｄとしたとき、１−（ｄ／Ｄ）×１００（％）で表される。   The cold working rate here is 1- (d / D) × 100, where D is the thickness of the hot-rolled steel sheet before cold working and d is the amount of thickness reduction by cold working. (%)

次に、この冷間圧延した熱延鋼板をＨＣｌ濃度１０〜１２質量％である酸洗液で、酸洗温度８５〜９５℃、酸洗時間４５〜１２０秒の条件で酸洗する。この条件での酸洗を、上述した冷間圧延を施した後に実施することによって、従来の酸洗よりも溶解深さを深くすることができ、スケールだけでなく、ＮｉやＰの表面に濃化部を除去することができる。それぞれの酸洗条件（ＨＣｌ濃度、酸洗温度、酸洗時間）が下限値未満であると、スケールが完全に除去できない、あるいはスケールは除去できてもＮｉなどの濃化部を除去できない。それぞれの酸洗条件が上限値を超えると溶解能が強すぎて、不均一に溶解されたり、ピット状に溶解され表面外観が損なわれてしまう場合がある。   Next, this cold-rolled hot-rolled steel sheet is pickled with a pickling solution having an HCl concentration of 10 to 12% by mass under conditions of a pickling temperature of 85 to 95 ° C. and a pickling time of 45 to 120 seconds. By performing the pickling under these conditions after performing the above-described cold rolling, the depth of dissolution can be made deeper than that of conventional pickling, and not only on the scale, but also on the surface of Ni or P. Can be removed. If each pickling condition (HCl concentration, pickling temperature, pickling time) is less than the lower limit value, the scale cannot be completely removed, or even if the scale can be removed, the concentrated portion such as Ni cannot be removed. If each pickling condition exceeds the upper limit value, the dissolving ability is too strong, and it may be dissolved non-uniformly or dissolved in a pit shape to impair the surface appearance.

なお上述した例では、酸化しやすいＰ、酸化しにくいＮｉを例にとり説明をしたが、これに限定されるものではない。例えば、Ｃｒ、Ｃｕ、Ｍｏ等についても同様に、上述した加熱条件の下で酸洗表面近傍まで引き込み、その後の酸洗のプロセスを通じて、これらの元素が濃化した地鉄を含めて削り取ることが可能となる。その結果、最終的に得られた鋼板表面においてＦｅ以外の元素の濃化部を低減させることが可能となり、表面処理性を向上させることが可能となる。   In the above-described example, description has been given by taking as an example P which is easily oxidized and Ni which is not easily oxidized, but is not limited thereto. For example, Cr, Cu, Mo, and the like can be similarly drawn into the vicinity of the pickling surface under the heating conditions described above, and then scraped off including the iron core enriched with these elements through the subsequent pickling process. It becomes possible. As a result, it becomes possible to reduce the concentration part of elements other than Fe on the steel plate surface finally obtained, and to improve surface treatment property.

以下、本発明の実施例について説明する。先ず、本発明の実施例として、上述した熱延鋼板の製造方法に基づいて熱延鋼板を作製した。具体的には、下記表１に示す組成で、厚さが２５０ｍｍのスラブを加熱温度ＴＳ℃に加熱した後、粗圧延機によって３５ｍｍの厚さまで粗圧延し、粗圧延鋼板を作製した。次に、この粗圧延鋼板に向けてデスケーリング装置により１５ＭＰａの圧力で水を噴射し、表面に生成したスケールを除去した後、直ちに７機の圧延スタンド間を連続的に通過させて熱間圧延する仕上げ圧延を行って、厚さが３．６ｍｍの熱延鋼板を作製した。 Examples of the present invention will be described below. First, as an example of the present invention, a hot-rolled steel sheet was produced based on the above-described method for producing a hot-rolled steel sheet. Specifically, a slab having a composition shown in Table 1 having a thickness of 250 mm was heated to a heating temperature T S ° C., and then roughly rolled to a thickness of 35 mm by a roughing mill to prepare a rough rolled steel sheet. Next, water is sprayed onto the rough rolled steel sheet at a pressure of 15 MPa by a descaling device to remove the scale generated on the surface, and then immediately passed between 7 rolling stands and hot rolled. The hot-rolled steel sheet having a thickness of 3.6 mm was produced by finish rolling.

この圧延した熱延鋼板は、巻取温度ＴＬ（℃）で巻き取り、その後冷間加工率Ｃｗ（％）で冷間圧延し、更にこれを酸洗槽に浸漬した。酸洗槽では、ＨＣｌ濃度ＬＨ（％）である酸洗液が満たされており、酸洗温度ＴＨ（℃）とし、酸洗時間はＩＮ（秒）に亘って酸洗を行う。 The rolled hot-rolled steel sheet was wound at a winding temperature T L (° C.), then cold-rolled at a cold working rate C w (%), and further immersed in a pickling tank. The pickling bath, HCl concentration L H (%) pickling solution is filled is, the pickling temperature T H (° C.), the pickling time performing pickling over I N (s).

このとき、各工程における条件（ＴＬ、Ｃｗ、ＬＨ、ＴＨ、ＩＮ）を変化させ、酸洗後の表面性状を観察した。この表面性状の観察については、実際に酸洗後の熱延鋼板表面に化成処理を施すことにより実行した。化成処理は、７０ｍｍ×１５０ｍｍサイズに切り出した鋼板を用いて実施し、表面に付着する油分を脱脂液で除去した後、表面調整剤（日本パーカライジング製の”PL-Z“溶液）に浸漬した後、日本パーカライジング製のリン酸鉄亜鉛処理液PB-L3020に浸漬させることで、鋼板表面にリン酸鉄亜鉛結晶を付着させる処理を施した。 At this time, the conditions (T L , C w , L H , T H , I N ) in each step were changed, and the surface properties after pickling were observed. This observation of the surface properties was performed by subjecting the hot-rolled steel sheet surface after pickling to chemical conversion treatment. The chemical conversion treatment is carried out using a steel plate cut out to a size of 70 mm × 150 mm, and after removing oil adhering to the surface with a degreasing solution, it is immersed in a surface conditioner (“PL-Z” solution manufactured by Nihon Parkerizing). The steel sheet was immersed in an iron zinc phosphate treatment solution PB-L3020 manufactured by Nihon Parkerizing, so that iron zinc phosphate crystals were attached to the steel sheet surface.

このリン酸鉄亜鉛処理後に、鋼板を水洗、乾燥させた。そして、この鋼板の中央部から２０ｍｍ四方の試験片を切り出し、表面の外観観察及びリン酸鉄亜鉛の結晶粒を走査型電子顕微鏡にて観察した。観察は試験片の表面全面について行い、リン酸鉄亜鉛結晶によって鋼板表面が被覆されているものを○とし、被覆されていない箇所があるものを×とした。なお、被覆されていないというのは、観察した試験片表面全面のうち、リン酸鉄亜鉛の結晶粒が付着していない１０ミクロンメートル四方以上の領域が２０ｍｍ四方の試験片について２箇所以上あるものを指す。   After the iron zinc phosphate treatment, the steel plate was washed with water and dried. And the test piece of 20 mm square was cut out from the center part of this steel plate, the external appearance observation of the surface, and the crystal grain of the iron zinc phosphate were observed with the scanning electron microscope. The observation was performed on the entire surface of the test piece. The case where the steel plate surface was coated with iron zinc phosphate crystals was marked with ◯, and the case where there was an uncoated portion was marked with x. It should be noted that uncovered means that there are two or more 10-micrometer-square regions on the 20-mm-square test piece where the crystal grains of zinc iron phosphate do not adhere to the entire surface of the observed specimen surface. Point to.

結果を下記表２にまとめて示す。また、下記表２には、各実施例及び比較例における加熱温度ＴＳ、巻取温度ＴＬ、冷間加工率Ｃｗ、ＨＣｌ濃度ＬＨ、酸洗温度ＴＨ、酸洗時間ＩＮも併せて示す。 The results are summarized in Table 2 below. In Table 2 below, the heating temperature T S , the coiling temperature T L , the cold working rate C w , the HCl concentration L H , the pickling temperature T H , and the pickling time I N in each example and comparative example are also shown. Also shown.

なお、下記表１に示す鋼組成における残部は、Ｆｅ及び不可避的不純物である。また、下記表１及び表２における下線は、本発明の範囲外であることを示す。   The balance in the steel composition shown in Table 1 below is Fe and inevitable impurities. Moreover, the underline in the following Table 1 and Table 2 shows that it is outside the scope of the present invention.

Figure 2009249714
Figure 2009249714

Figure 2009249714
Figure 2009249714

表１に示す本発明鋼１〜１８は、何れも上記規定した成分の範囲内にある。これに対して、比較例１９はＰの含有量が、比較鋼２０はＳｉの含有量が、比較鋼２１はＭｎ、Ｓの含有量が、比較例１９、２３はＰの含有量が、比較例２２はＮｉの含有量が、比較例２３はＰ、Ｎｉの含有量が本発明において規定した成分の範囲から逸脱している。   Inventive steels 1 to 18 shown in Table 1 are all in the range of the above-defined components. In contrast, Comparative Example 19 has a P content, Comparative Steel 20 has a Si content, Comparative Steel 21 has a Mn and S content, and Comparative Examples 19 and 23 have a P content. In Example 22, the content of Ni deviates from the range of the components defined in the present invention, and in Comparative Example 23, the content of P and Ni deviates from the range of components specified in the present invention.

表２に示す本発明例１〜１４は、何れも本発明鋼１〜１８の何れか１以上を実験で使用し、各製造条件は本発明で規定した条件の範囲内としている。これに対して比較例１５〜２０は、何れも本発明鋼１〜１８の何れか１以上を実験で使用しているが、製造条件の何れかが本発明で規定した条件の範囲外としている。比較例２１〜２３は、何れも比較鋼１９〜２３を実験で使用するものであり、本発明で規定した成分の範囲を逸脱させてはいるが、各製造条件は本発明で規定した条件の範囲内である。   In each of Invention Examples 1 to 14 shown in Table 2, any one or more of Invention Steels 1 to 18 are used in an experiment, and each production condition is within the range defined by the present invention. On the other hand, in Comparative Examples 15 to 20, any one or more of the steels of the present invention 1 to 18 are used in the experiment, but any of the manufacturing conditions is out of the range defined by the present invention. . In Comparative Examples 21 to 23, the comparative steels 19 to 23 are used in experiments, and deviate from the range of components defined in the present invention. However, each production condition is the same as the condition defined in the present invention. Within range.

表２の結果から示すように表面性状は、本発明例１〜１４において何れも良好であった。   As shown from the results in Table 2, the surface properties were all good in Examples 1 to 14 of the present invention.

これに対して比較例１５、２０は、巻取温度ＴＬが本発明で規定した下限より低く、上述したようにＰの表面付近の濃度が却って向上する結果、表面性状が悪化していた。また、比較例１６は、冷間加工率Ｃｗが０％であり本発明で規定した下限より低く、微細なクラックを多数導入するには不十分であり、酸洗により熱延鋼板を表面からより深く溶解することができず、表面性状が悪化していた。また、比較例１７は、酸洗温度ＴＨが６８℃であり本発明で規定した下限より低く、スケールが完全に除去できない等の理由で表面性状が悪化していた。また比較例１８は、加熱温度が１０２０℃であり本発明で規定した下限より低く、また、冷間加工率Ｃｗも本発明で規定した範囲より低く、表面性状が悪化していた。また比較例１９は、ＨＣｌ濃度ＬＨが５％であり、本発明で規定した下限より低いために、スケールが完全に除去できない、あるいはスケールは除去できてもＮｉなどの濃化部を除去できない等の理由で表面性状が悪化していた。更に、比較例２１〜２３は、比較鋼１９〜２３を供試材として使用したものであり、本発明で規定した成分の範囲から逸脱しているため、表面性状が悪化していた。 In contrast, in Comparative Examples 15 and 20, the coiling temperature TL was lower than the lower limit defined in the present invention, and as described above, the surface properties deteriorated as a result of the concentration near the surface of P being improved. In Comparative Example 16, the cold working rate Cw is 0%, which is lower than the lower limit defined in the present invention, and is insufficient for introducing a large number of fine cracks. It was not possible to dissolve deeper and the surface properties were deteriorated. In Comparative Example 17, pickling temperature T H is lower than the lower limit as defined there present invention at 68 ° C., why the surface property of such scales can not be completely removed is deteriorated. In Comparative Example 18, the heating temperature was 1020 ° C., which was lower than the lower limit specified in the present invention, and the cold working rate Cw was also lower than the range specified in the present invention, and the surface properties were deteriorated. The Comparative Example 19, HCl concentration L H is 5%, the lower limit as defined in the present invention, the scale can not be completely removed, or the scale can not be removed thickening unit such as Ni also be removed The surface properties were deteriorated for the reasons described above. Further, Comparative Examples 21 to 23 used Comparative Steels 19 to 23 as test materials and deviated from the range of the components defined in the present invention, so that the surface properties were deteriorated.

Claims (2)

質量％で、Ｃ：０．００１〜０．０５％、Ｓｉ：０．００１〜０．２％、Ｍｎ：０．０１〜０．４％、Ｐ：０．００１〜０．１％、Ｓ：０．００１〜０．０２％、Ａｌ：０．００５〜０．０９％、Ｎ：０．００１〜０．０１５％、Ｎｉ：０．００２〜０．１％を含有し、残部が鉄および不可避的不純物からなる鋼組成のスラブを１１５０℃以上の温度に加熱する工程と、
前記加熱したスラブに対して熱間圧延を施すことにより得られた熱延鋼板を７００℃〜８５０℃の巻取温度で巻き取る工程と、
前記巻き取った熱延鋼板を冷間加工率１〜２．５％で冷間圧延する工程と、
前記冷間圧延した熱延鋼板を、ＨＣｌ濃度１０〜１５質量％である酸洗液により酸洗温度８５〜９５℃、酸洗時間４５〜１２０秒で酸洗する工程とを有すること
を特徴とする表面処理性に優れた熱延鋼板の製造方法。 In mass%, C: 0.001-0.05%, Si: 0.001-0.2%, Mn: 0.01-0.4%, P: 0.001-0.1%, S: 0.001-0.02%, Al: 0.005-0.09%, N: 0.001-0.015%, Ni: 0.002-0.1%, the balance being iron and inevitable Heating a steel composition slab composed of mechanical impurities to a temperature of 1150 ° C. or higher;
A step of winding a hot-rolled steel sheet obtained by subjecting the heated slab to hot rolling at a winding temperature of 700 ° C. to 850 ° C .;
Cold rolling the rolled hot-rolled steel sheet at a cold working rate of 1 to 2.5%;
A step of pickling the cold-rolled hot-rolled steel sheet with a pickling solution having an HCl concentration of 10 to 15 mass% at a pickling temperature of 85 to 95 ° C and a pickling time of 45 to 120 seconds. The manufacturing method of the hot-rolled steel plate excellent in the surface treatment property to do. 前記スラブは、更に質量％で、Ｃｒ：０．５％以下、Ｃｕ：０．５％以下、Ｔｉ：０．１％以下、Ｎｂ：０．０５％以下、Ｖ：０．０５％以下、Ｍｏ：０．０５％以下、Ｃａ：０．００５％以下、Ｂ：０．００５％以下の１種または２種以上を、さらに含有すること
を特徴とする請求項１記載の表面処理性に優れた熱延鋼板の製造方法。 The slab is further in mass%, Cr: 0.5% or less, Cu: 0.5% or less, Ti: 0.1% or less, Nb: 0.05% or less, V: 0.05% or less, Mo The surface treatment property according to claim 1, further comprising one or more of 0.05% or less, Ca: 0.005% or less, and B: 0.005% or less. A method for producing a hot-rolled steel sheet.
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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104480391A (en) * 2014-11-24 2015-04-01 江苏省沙钢钢铁研究院有限公司 Hot-rolled pickled plate and production method thereof
JP2016041833A (en) * 2014-08-14 2016-03-31 Ｊｆｅスチール株式会社 Si-CONTAINING HOT ROLLED STEEL SHEET WITH EXCELLENT CHEMICAL CONVERSION TREATMENT PROPERTY AND MANUFACTURING METHOD OF THE SAME
CN105543682A (en) * 2015-12-22 2016-05-04 本钢板材股份有限公司 Hot-rolled pickled plate used for automobile structure
CN108517459A (en) * 2018-04-04 2018-09-11 本钢板材股份有限公司 A kind of boracic low-carbon hot-rolling acid-cleaning plate and its production method
CN108517460A (en) * 2018-04-04 2018-09-11 本钢板材股份有限公司 A kind of boracic low-carbon hot-rolling acid-cleaning plate and its production method
CN109252110A (en) * 2018-11-06 2019-01-22 鞍钢股份有限公司 A kind of automobile low-carbon hot-rolling acid-cleaning plate and preparation method thereof
CN110055458A (en) * 2019-03-28 2019-07-26 江苏省沙钢钢铁研究院有限公司 A kind of production method of hot rolling acid-cleaning Automobile Plate
WO2021157692A1 (en) * 2020-02-06 2021-08-12 日本製鉄株式会社 Hot-rolled steel sheet and method for manufacturing same
CN114892095A (en) * 2022-06-01 2022-08-12 张家港扬子江冷轧板有限公司 High-strength weathering steel for thin S450NH carriage and preparation method thereof

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61195707A (en) * 1985-02-25 1986-08-30 Sumitomo Metal Ind Ltd Production of hot rolled steel sheet having excellent descalability
JPH09295028A (en) * 1996-05-08 1997-11-18 Nkk Corp Production of hot-rolled steel plate excellent in pickling property and surface characteristic
JP2000102815A (en) * 1998-09-25 2000-04-11 Nkk Corp Method for manufacturing hot rolling steel plate superior in acid pickling performance and surface property
JP2003236608A (en) * 2002-02-18 2003-08-26 Nippon Steel Corp Pickling device line and pickling method for hot rolled plate
JP2005146318A (en) * 2003-11-13 2005-06-09 Nippon Steel Corp Hot-rolled steel plate superior in chemical conversion treatability, and manufacturing method therefor

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61195707A (en) * 1985-02-25 1986-08-30 Sumitomo Metal Ind Ltd Production of hot rolled steel sheet having excellent descalability
JPH09295028A (en) * 1996-05-08 1997-11-18 Nkk Corp Production of hot-rolled steel plate excellent in pickling property and surface characteristic
JP2000102815A (en) * 1998-09-25 2000-04-11 Nkk Corp Method for manufacturing hot rolling steel plate superior in acid pickling performance and surface property
JP2003236608A (en) * 2002-02-18 2003-08-26 Nippon Steel Corp Pickling device line and pickling method for hot rolled plate
JP2005146318A (en) * 2003-11-13 2005-06-09 Nippon Steel Corp Hot-rolled steel plate superior in chemical conversion treatability, and manufacturing method therefor

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016041833A (en) * 2014-08-14 2016-03-31 Ｊｆｅスチール株式会社 Si-CONTAINING HOT ROLLED STEEL SHEET WITH EXCELLENT CHEMICAL CONVERSION TREATMENT PROPERTY AND MANUFACTURING METHOD OF THE SAME
CN104480391A (en) * 2014-11-24 2015-04-01 江苏省沙钢钢铁研究院有限公司 Hot-rolled pickled plate and production method thereof
CN105543682A (en) * 2015-12-22 2016-05-04 本钢板材股份有限公司 Hot-rolled pickled plate used for automobile structure
CN108517459A (en) * 2018-04-04 2018-09-11 本钢板材股份有限公司 A kind of boracic low-carbon hot-rolling acid-cleaning plate and its production method
CN108517460A (en) * 2018-04-04 2018-09-11 本钢板材股份有限公司 A kind of boracic low-carbon hot-rolling acid-cleaning plate and its production method
CN109252110A (en) * 2018-11-06 2019-01-22 鞍钢股份有限公司 A kind of automobile low-carbon hot-rolling acid-cleaning plate and preparation method thereof
CN110055458A (en) * 2019-03-28 2019-07-26 江苏省沙钢钢铁研究院有限公司 A kind of production method of hot rolling acid-cleaning Automobile Plate
WO2021157692A1 (en) * 2020-02-06 2021-08-12 日本製鉄株式会社 Hot-rolled steel sheet and method for manufacturing same
JPWO2021157692A1 (en) * 2020-02-06 2021-08-12
JP7368763B2 (en) 2020-02-06 2023-10-25 日本製鉄株式会社 Hot rolled steel sheet and its manufacturing method
CN114892095A (en) * 2022-06-01 2022-08-12 张家港扬子江冷轧板有限公司 High-strength weathering steel for thin S450NH carriage and preparation method thereof

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