JP2005290552A - Chemical-conversion-coated steel sheet superior in corrosion resistance, and adhesiveness and adhesivity to paint film - Google Patents
Chemical-conversion-coated steel sheet superior in corrosion resistance, and adhesiveness and adhesivity to paint film Download PDFInfo
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- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
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- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
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- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
- C23C28/34—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
- C23C28/345—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer
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Abstract
Description
本発明は、環境に有害な六価クロムを含まず優れた耐食性,塗装性,塗膜密着性,接着性を呈し、外装材,内装材,表装材,車両用鋼板等として有用な化成処理鋼板に関する。 The present invention does not contain hexavalent chromium harmful to the environment, exhibits excellent corrosion resistance, paintability, coating film adhesion, and adhesion, and is useful as an exterior material, interior material, cover material, vehicle steel plate, etc. About.
亜鉛めっき鋼板,亜鉛合金めっき鋼板等は、海塩粒子飛散雰囲気や高温多湿雰囲気で使用すると、外観劣化の原因となる白錆が鋼板表面に発生し、めっき層の犠牲防食作用も損なわれる。白錆の発生は、クロメート処理,リン酸塩処理等によって防止できる。しかし、クロメート処理は、生成した皮膜からの六価クロムの溶出が避けられない。リン酸塩処理でも、リン酸塩処理後にクロメート処理を通常必要とすることから、六価クロム溶出の問題は未解決である。 When galvanized steel sheets, zinc alloy plated steel sheets and the like are used in a sea salt particle scattering atmosphere or a high-temperature and high-humidity atmosphere, white rust that causes external appearance deterioration occurs on the steel sheet surface, and the sacrificial anticorrosive action of the plating layer is also impaired. Generation of white rust can be prevented by chromate treatment, phosphate treatment, and the like. However, in chromate treatment, elution of hexavalent chromium from the formed film is inevitable. Even in the phosphate treatment, the chromate treatment is usually required after the phosphate treatment, so the problem of hexavalent chromium elution has not been solved.
環境に有害な六価クロムを含まない化成皮膜を形成するため、リン酸塩処理の改良が検討されている。たとえば、特許文献1は、ヒドラジン誘導体,シリカ微粒子,金属表面に対してエッチング作用のある酸を含む処理液でリン酸塩皮膜を後処理することを紹介している。特許文献2では、リン酸塩処理皮膜を介しチオカルボニル基含有化合物を含む有機樹脂皮膜を亜鉛系めっき鋼板に設けることを紹介している。
化成処理鋼板は、通常、鉄鋼メーカ側でリン酸塩処理され、ユーザ側で製品形状に成形加工されている。成形加工に際し、従来のリン酸塩皮膜では皮膜構成成分である無機質のリン酸塩が硬質で延性がないため、亀裂,剥離等の皮膜欠陥が導入されやすい。皮膜欠陥は腐食発生の起点となり、化成皮膜の耐食性改善作用や塗膜密着性が極端に低下する。めっき層/リン酸塩皮膜の密着性を改善するため、リン酸塩処理した亜鉛めっき鋼板の表面粗さを調整する方法(特許文献3),表面粗さに加えてリン酸塩皮膜の膜厚を調整する方法(特許文献4)等が提案されているが、依然としてユーザ側での加工性,加工後密着性を十分に満足させるに至っていない。
本発明は、高耐食性を呈するZn-Al-Mg合金めっき鋼板を基材に選択し、リン酸塩系の化成処理がめっき層表面に及ぼす影響を調査・検討した結果得られた知見をベースとし、めっき層にリン酸塩結晶が食い込んだリン酸塩皮膜を形成することにより、成形加工による亀裂,剥離が抑制され、優れた皮膜密着性を維持する化成処理鋼板を提供することを目的とする。 The present invention is based on the knowledge obtained as a result of investigating and examining the influence of phosphate-based chemical conversion treatment on the surface of the plating layer by selecting Zn-Al-Mg alloy-plated steel sheet exhibiting high corrosion resistance as the base material. An object of the present invention is to provide a chemical conversion treated steel sheet that is formed by forming a phosphate film in which a phosphate crystal penetrates into a plating layer, thereby suppressing cracking and peeling due to forming and maintaining excellent film adhesion. .
本発明の化成処理鋼板は、めっき層最表面に占める〔Al/Zn/Zn2Mgの三元共晶組織〕の割合が60面積%以上である溶融Zn-Al-Mg合金めっき鋼板を基材とし、基材のめっき層表面をリン酸塩皮膜,析出層,有機樹脂系の化成皮膜で覆っている。析出層は、付着量:0.05〜5.0mg/m2でNi,Co,Feから選ばれた少なくとも一種を析出させた層及び/又は付着量:0.05〜30mg/m2でMnを析出させた層である。リン酸塩皮膜は、基部がめっき層に食い込んでめっき層から起立する平均粒径:0.5〜5.0μmのリン酸塩結晶からなる。化成皮膜は、バルブメタルの酸化物又は水酸化物とバルブメタルのフッ化物とを含み、リン酸塩結晶の間で露出しためっき層又は析出層の上に形成された界面反応層をもち、バブルメタルの酸化物又は水酸化物とバブルメタルのフッ化物が共存した有機樹脂皮膜が界面反応層の上に形成されている。 The chemical conversion treated steel sheet of the present invention is based on a molten Zn—Al—Mg alloy plated steel sheet in which the ratio of [Al / Zn / Zn 2 Mg ternary eutectic structure] to the outermost surface of the plating layer is 60 area% or more. And the plating layer surface of the base material is covered with a phosphate film, a deposited layer, and an organic resin-based chemical conversion film. Deposition layer coating weight: range from 0.05 to 5.0 mg / m 2 in Ni, Co, the layer was deposited at least one selected from Fe and / or coating weight: Mn in 0.05~30mg / m 2 It is the layer which precipitated. The phosphate film is composed of phosphate crystals having an average particle size of 0.5 to 5.0 μm whose base portion bites into the plating layer and stands up from the plating layer. The chemical conversion film contains an oxide or hydroxide of valve metal and a fluoride of valve metal, and has an interfacial reaction layer formed on a plating layer or a deposited layer exposed between phosphate crystals, and a bubble. An organic resin film in which a metal oxide or hydroxide and a bubble metal fluoride coexist is formed on the interface reaction layer.
リン酸塩処理による塗膜密着性やフィルム密着性を改善する上で、めっき層最表面に占めるリン酸塩結晶の割合を50面積%以上、めっき層に食い込むリン酸塩結晶の平均深さを0.05μm以上にすることが好ましい。化成皮膜のバルブメタルには、Ti,Zr,Hf,V,Nb,Ta,Mo,W等が使用される。化成皮膜は、0.001μm以上でリン酸塩皮膜の膜厚の10%以下に膜厚を規制することが好ましい。 In improving coating film adhesion and film adhesion by phosphate treatment, the proportion of phosphate crystals occupying the outermost surface of the plating layer is 50 area% or more, and the average depth of phosphate crystals that bite into the plating layer The thickness is preferably 0.05 μm or more. Ti, Zr, Hf, V, Nb, Ta, Mo, W, etc. are used for the valve metal of a chemical conversion film. The film thickness of the chemical conversion film is preferably 0.001 μm or more and 10% or less of the film thickness of the phosphate film.
Ni,Co,Fe,Mn等を含むリン酸処理液で溶融Zn-Al-Mg合金めっき鋼板をリン酸塩処理すると、めっき層の表層に食い込んだ状態でリン酸塩結晶が生成する。そのため、めっき層に対するリン酸塩皮膜は、従来の亜鉛系めっき鋼板をリン酸塩処理した場合に得られるリン酸塩皮膜に比較して格段に優れた密着性を呈し、成形加工後にも健全な状態に維持される。
めっき層に対するリン酸塩結晶の食込みは、次のメカニズムによるものと推察され、溶融Zn-Al-Mg合金めっき鋼板とNi,Co,Fe,Mn等を含むリン酸処理液との組合せによって初めて生じる現象である(図1)。以下の説明ではNiを例に置換析出元素としているが、Co,Fe及び/又はMnを含むリン酸処理液を使用した場合でも同様にめっき層に食い込んだリン酸塩結晶が生成する。
When the molten Zn—Al—Mg alloy-plated steel sheet is subjected to a phosphate treatment with a phosphoric acid treatment solution containing Ni, Co, Fe, Mn, etc., phosphate crystals are generated in a state of being bitten into the surface layer of the plating layer. Therefore, the phosphate film on the plating layer exhibits much better adhesion than the phosphate film obtained when the conventional zinc-based plated steel sheet is subjected to phosphate treatment, and is sound even after forming. Maintained in a state.
It is presumed that the phosphate crystal bites into the plating layer due to the following mechanism, and it occurs for the first time by a combination of a hot-dip Zn-Al-Mg alloy-plated steel sheet and a phosphating solution containing Ni, Co, Fe, Mn, etc. This is a phenomenon (FIG. 1). In the following description, Ni is used as an example of the substitutional precipitation element. However, even when a phosphating solution containing Co, Fe and / or Mn is used, phosphate crystals that have penetrated into the plating layer are generated.
溶融Zn-Al-Mg合金めっき鋼板は、めっき層の大部分が〔Al/Zn/Zn2Mgの三元共晶組織〕の微細組織になっている。Ni含有処理液でめっき層をリン酸塩処理すると、三元共晶組織のなかで表面電位が最も低いZn2Mg相で優先的にNiの置換析出反応が生じる。貴な金属であるNiがZn2Mg相の表面に析出すると、Zn2Mg相,析出NiとZn相との間に腐食電流が流れ、Zn相が優先的に溶解する。Zn相の溶解は、エッチングされ難いAl相がめっき層に存在するため深さ方向に進行する。Zn相の溶解に伴ってリン酸塩結晶が析出するので、Zn相が深くエッチングされた個所では根の深いリン酸塩結晶となる。 In the molten Zn—Al—Mg alloy-plated steel sheet, most of the plating layer has a microstructure of [Al / Zn / Zn 2 Mg ternary eutectic structure]. When the plating layer is phosphate-treated with a Ni-containing treatment solution, a substitutional precipitation reaction of Ni occurs preferentially in the Zn 2 Mg phase having the lowest surface potential in the ternary eutectic structure. When a noble metal Ni is deposited on the surface of the Zn 2 Mg phase, Zn 2 Mg phase, the corrosion current flows between the deposition Ni and Zn phase, Zn phase is preferentially dissolved. The dissolution of the Zn phase proceeds in the depth direction because an Al phase that is difficult to etch exists in the plating layer. Since phosphate crystals are precipitated as the Zn phase dissolves, the phosphate crystals are deeply rooted where the Zn phase is deeply etched.
これに対し、めっき層がほぼ単一な組織を呈する電気亜鉛めっき鋼板や溶融亜鉛めっき鋼板をNi含有処理液でリン酸塩処理すると、めっき層のほぼ全面にNiが置換析出する。析出Niのないめっき層が深さ方向及び水平方向に溶解し、リン酸塩結晶が析出する。しかし、深さ方向に沿った溶解が進行しがたいため、析出したリン酸塩結晶がめっき層に僅かに食い込むだけであり、水平方向に成長した比較的大粒径の結晶となる。 On the other hand, when an electrogalvanized steel sheet or a hot dip galvanized steel sheet in which the plated layer has a substantially single structure is subjected to phosphate treatment with a Ni-containing treatment solution, Ni is substituted and deposited on almost the entire surface of the plated layer. The plating layer without precipitated Ni is dissolved in the depth direction and the horizontal direction, and phosphate crystals are precipitated. However, since dissolution along the depth direction is difficult to proceed, the precipitated phosphate crystal slightly bites into the plating layer, resulting in a crystal having a relatively large grain size grown in the horizontal direction.
リン酸塩結晶2は、根深くめっき層1に食い込んだ状態でめっき層1から起立する方向に成長する。リン酸塩結晶2の間ではめっき層1が露出し、或いはNi析出層3が形成されている。バルブメタルのフッ化物を含むクロムフリー化成処理液でリン酸塩処理後のめっき層1を処理すると、処理液のエッチング作用によりリン酸塩結晶2の一部が溶解し、溶解したリン酸塩成分が処理液成分と共にめっき層1の露出表面と反応し、界面反応層4aが生成し、界面反応層4aの上に有機樹脂系皮膜4bが生成する(図2)。界面反応層4a,有機樹脂系皮膜4bからなる化成皮膜4は、自己修復作用がありめっき層1の露出表面を環境から遮断する。めっき層1から起立しているリン酸塩結晶2の表面にも粒状の反応生成物5が沈積する。
The
クロムフリー化成皮膜4の界面反応層4a,有機樹脂系皮膜4bには、バルブメタルの酸化物又は水酸化物及びバルブメタルのフッ化物が共存している。バルブメタルの酸化物又は水酸化物は、優れた環境遮断能を呈し、腐食性雰囲気からめっき層1を保護する。バルブメタルのフッ化物は、腐食性雰囲気に曝されると溶出し、難溶性の酸化物又は水酸化物となって再析出する過程でリン酸塩皮膜,化成皮膜4の欠陥部を自己修復する。
In the interfacial reaction layer 4a and the
クロムフリー化成皮膜4は、隣接リン酸塩結晶2の間で露出しているめっき層1の表面に形成されるため、未処理のめっき層1やNi析出層3に形成される化成皮膜に比べ成長が促進され、環境遮断能,自己修復作用が格段に向上する。環境遮断能,自己修復作用は膜厚0.001μm以上の化成皮膜4でみられるが、界面反応層4aが厚く成長しすぎるとリン酸塩結晶2,界面反応層4a共に硬質であるため加工時の変形により脱落する場合があるので、めっき層1の表面から起立するリン酸塩結晶2の平均高さの10%以下に界面反応層4aの厚みを制御することが好ましい。界面反応層4aの厚みは、クロムフリー化成処理液の濃度や処理時間等で制御できる。リン酸塩結晶2の突出高さは1〜2μmの微細サイズから5〜20μmの通常サイズまであるので、該突出高さに応じて界面反応層4aの厚みを選定する。
Since the chromium-free chemical conversion film 4 is formed on the surface of the
化成皮膜4は、延性のある有機樹脂系皮膜4bを主としているためある程度の加工を受けても健全な皮膜状態を維持する。しかも、リン酸塩結晶2で化成皮膜4が分断されているため、めっき層1に対する密着性低下も軽減される。リン酸塩結晶2の表面に析出している粒状反応生成物5も、自己修復作用を呈するフッ化物の供給源となる。更に、硬質で延性のないリン酸塩結晶2のシャープな角部がクロムフリー化成処理液のエッチング作用で消失するので、プレス成形等の加工時に亀裂や剥離がリン酸塩皮膜3に生じ難くなる。
Since the chemical conversion film 4 is mainly composed of a ductile
化成処理原板に使用される溶融Zn-Al-Mg合金めっき鋼板は、Al:2.5〜15質量%,Mg:2.0〜4.0質量%を含み残部が実質的にZnの合金めっき浴を用いた溶融めっき法で製造される。合金めっき浴の組成は、必要とする形態のリン酸塩結晶の形成に有効な〔Al/Zn/Zn2Mgの三元共晶組織〕の微細組織を主とするめっき層が鋼板表面に形成されるように所定組成に調整される。〔Al/Zn/Zn2Mgの三元共晶組織〕が60面積%以上(好ましくは、80面積%以上)になると、リン酸塩処理液との反応性が高くなる。 The hot-dip Zn—Al—Mg alloy-plated steel sheet used for the chemical conversion raw plate contains Al: 2.5-15 mass%, Mg: 2.0-4.0 mass%, and the balance is substantially Zn alloy plating. Manufactured by hot dipping using a bath. The composition of the alloy plating bath is such that a plating layer mainly composed of a microstructure of [Al / Zn / Zn 2 Mg ternary eutectic structure] effective on the formation of phosphate crystals in the required form is formed on the surface of the steel sheet. To a predetermined composition. When [Al / Zn / Zn 2 Mg ternary eutectic structure] is 60 area% or more (preferably 80 area% or more), the reactivity with the phosphating solution increases.
めっき層の金属組織を〔Al/Zn/Zn2Mgの三元共晶組織〕とする場合、外観及び耐食性に悪影響を与えるZn11Mg2相の生成・成長を抑制するためTi,B,Ti-B合金又はTi,B含有化合物をめっき浴に添加することが有益である。めっき浴に対する添加量は、Ti:0.001〜0.1質量%,B:0.001〜0.045質量%の範囲で定めることが好ましい。過剰なTi,Bの添加はめっき層に析出物が成長する原因であり、却ってリン酸塩処理性を阻害することがある。
更に、加工時のめっき密着性を向上させるため、めっき層と素地鋼との界面におけるAl-Fe合金層の成長を抑制する作用のあるSiを0.005〜0.5質量%の範囲で添加することもできる。
When the metal structure of the plating layer is [Al / Zn / Zn 2 Mg ternary eutectic structure], Ti, B, Ti are used to suppress the formation and growth of the Zn 11 Mg 2 phase which adversely affects the appearance and corrosion resistance. It is beneficial to add a B alloy or a Ti, B containing compound to the plating bath. The addition amount to the plating bath is preferably determined in the range of Ti: 0.001 to 0.1% by mass and B: 0.001 to 0.045% by mass. Excessive addition of Ti and B is a cause for the growth of precipitates in the plating layer, which may inhibit the phosphate treatment.
Further, in order to improve plating adhesion during processing, Si having an action of suppressing the growth of the Al—Fe alloy layer at the interface between the plating layer and the base steel is added in the range of 0.005 to 0.5 mass%. You can also
リン酸塩処理液は、リン酸イオン濃度を0.03〜0.5モル/l,金属イオン濃度を0.01〜0.5モル/lの範囲に調整することが好ましい。硝酸イオンを含ませる場合、硝酸イオン濃度を0.01〜1.0モル/lの範囲に調整する。リン酸イオン濃度:0.03モル/l未満では短時間処理でリン酸塩結晶が充分に析出せず、逆に0.5モル/lを超えるとリン酸塩処理液の安定性が低下し、スラッジが発生し易くなる。金属イオン濃度:0.01〜0.5モル/lは各種金属イオンを合計した値であり、0.01モル/l未満では短時間処理でリン酸塩結晶を充分に析出させることができず、逆に0.5モル/lを超えるとリン酸塩処理液の安定性が低下する。硝酸イオンによる反応促進効果は0.01モル/l以上でみられるが、1.0モル/lを超える過剰量の硝酸イオンが含まれると酸化作用によりめっき層の表面が不活性化し、却って反応性が低下する。 In the phosphating solution, it is preferable to adjust the phosphate ion concentration to a range of 0.03 to 0.5 mol / l and the metal ion concentration to a range of 0.01 to 0.5 mol / l. When nitrate ions are included, the nitrate ion concentration is adjusted to a range of 0.01 to 1.0 mol / l. When the phosphate ion concentration is less than 0.03 mol / l, phosphate crystals are not sufficiently precipitated in a short time treatment. Conversely, when the concentration exceeds 0.5 mol / l, the stability of the phosphate treatment solution decreases. Sludge is likely to occur. Metal ion concentration: 0.01 to 0.5 mol / l is a total value of various metal ions. If it is less than 0.01 mol / l, phosphate crystals cannot be sufficiently precipitated in a short time treatment. On the other hand, if it exceeds 0.5 mol / l, the stability of the phosphating solution is lowered. The reaction promoting effect by nitrate ions is observed at 0.01 mol / l or more, but if an excessive amount of nitrate ions exceeding 1.0 mol / l is included, the surface of the plating layer is inactivated by the oxidation action and reacts instead. Sex is reduced.
リン酸イオンに加えてZn,Mn,Mg,Ca,Ni,Co,Fe等の金属イオンを必要に応じて添加したリン酸処理液が知られているが、本発明では、Ni,Co,Fe,Mnの少なくとも一種の金属イオンを含んだリン酸塩処理液を使用する。Ni,Co,Fe,Mnは、溶融Zn-Al-Mg合金めっき鋼板の〔Al/Zn/Zn2Mg三元共晶組織〕の中で表面電位が最も低いZn2Mg相に優先的に置換析出し、貴な金属であるNi,Co,Fe又はMn化合物がZn2Mg相に析出することで近傍のZn相が優先的に溶解する。Zn相の溶解は深さ方向に進行し、Zn相の溶解に伴ってリン酸塩結晶が析出するので根の深いリン酸塩結晶となる。析出したリン酸塩結晶は、〔Al/Zn/Zn2Mg三元共晶組織〕の微細組織を反映して微細で緻密な皮膜を形成する。 A phosphoric acid treatment solution is known in which metal ions such as Zn, Mn, Mg, Ca, Ni, Co, and Fe are added as needed in addition to phosphate ions. In the present invention, Ni, Co, and Fe are known. A phosphating solution containing at least one metal ion of Mn is used. Ni, Co, Fe, and Mn are preferentially replaced with the Zn 2 Mg phase having the lowest surface potential in the [Al / Zn / Zn 2 Mg ternary eutectic structure] of the molten Zn—Al—Mg alloy-plated steel sheet. Precipitating and precipitating Ni, Co, Fe or Mn compound in the Zn 2 Mg phase preferentially dissolves the nearby Zn phase. The dissolution of the Zn phase proceeds in the depth direction, and a phosphate crystal is precipitated with the dissolution of the Zn phase, so that the phosphate crystal has a deep root. The precipitated phosphate crystals form a fine and dense film reflecting the microstructure of [Al / Zn / Zn 2 Mg ternary eutectic structure].
リン酸塩処理液は、好ましくは0.001〜0.1モル/lのNi,Co,Fe,Mnを含む。0.001モル/l以上のNi,Co,Fe,MnでZn相の溶解が十分進行し、根が深く密着性の良好なリン酸塩結晶が生成する。しかし、0.1モル/lを超える過剰量のNi,Co,Fe,Mnが含まれると、貴な金属又は化合物の置換析出量が過多になりリン酸塩皮膜の耐食性低下が懸念される。
溶融Zn-Al-Mg合金めっき鋼板をリン酸塩処理するので、めっき層から溶出したAlによるリン酸塩反応の阻害が懸念されるが、リン酸塩処理液にフッ化物を添加することにより溶出Alの悪影響を抑制できる。フッ化物としてはフッ化ナトリウム、フッ化カリウム、フッ化水素ナトリウム等があり、フリーのフッ素イオン濃度が30ppm以上でフッ化物の添加効果が顕著になる。連続的な操業を可能とする上では、一定量のフッ化物を連続的にリン酸塩処理液に添加し、フッ素イオン濃度を30ppm以上に維持することが好ましい。
The phosphating solution preferably contains 0.001 to 0.1 mol / l Ni, Co, Fe, Mn. With 0.001 mol / l or more of Ni, Co, Fe, and Mn, dissolution of the Zn phase proceeds sufficiently, and phosphate crystals with deep roots and good adhesion are formed. However, when an excessive amount of Ni, Co, Fe, or Mn exceeding 0.1 mol / l is contained, the amount of substitutional precipitation of a noble metal or compound becomes excessive, and there is a concern that the corrosion resistance of the phosphate film is lowered.
Since the molten Zn-Al-Mg alloy-plated steel sheet is phosphate-treated, there is concern about the inhibition of the phosphate reaction by Al eluted from the plating layer, but elution by adding fluoride to the phosphate treatment solution The adverse effect of Al can be suppressed. Fluoride includes sodium fluoride, potassium fluoride, sodium hydrogen fluoride and the like, and the effect of adding fluoride becomes remarkable when the free fluorine ion concentration is 30 ppm or more. In order to enable continuous operation, it is preferable that a certain amount of fluoride is continuously added to the phosphating solution to maintain the fluorine ion concentration at 30 ppm or more.
リン酸塩処理は、好ましくは液温40〜80℃の範囲で実施される。液温が40℃に達しない場合、短時間処理ではリン酸塩結晶の析出が不充分となる。逆に、80℃を超える液温ではリン酸塩処理液の安定性が低下し、スラッジの発生や水分の蒸発が多くなり連続操業での濃度管理が難しくなる。液温が40〜80℃のリン酸塩処理液を使用する限り、スプレー処理であれば2〜6秒程度、浸漬処理であれば3〜9秒程度で必要とするリン酸塩皮膜が形成される。処理時間を長く設定しても、リン酸塩の析出が飽和状態になり外観が変化せず問題は無い。また、めっき層表面に常に新液を供給し、リン酸塩結晶析出時に界面のpH上昇を抑制するとき、処理液の反応性が向上し、根の深いリン酸塩結晶が生成する。 Phosphate treatment is preferably carried out at a liquid temperature in the range of 40 to 80 ° C. When the liquid temperature does not reach 40 ° C., phosphate crystals are not sufficiently precipitated by short-time treatment. On the other hand, when the liquid temperature exceeds 80 ° C., the stability of the phosphating solution decreases, and sludge generation and water evaporation increase, making it difficult to manage the concentration in continuous operation. As long as a phosphating solution having a liquid temperature of 40 to 80 ° C. is used, the necessary phosphate film is formed in about 2 to 6 seconds for spraying and about 3 to 9 seconds for immersion. The Even if the treatment time is set long, there is no problem because the precipitation of phosphate becomes saturated and the appearance does not change. Further, when a new solution is constantly supplied to the surface of the plating layer to suppress an increase in pH at the interface during precipitation of phosphate crystals, the reactivity of the treatment solution is improved, and deeply rooted phosphate crystals are generated.
40℃以上に加温したリン酸処理液を用いて溶融Zn-Al-Mg合金めっき鋼板を処理すると、反応性が高いためめっき層表面にリン酸塩の結晶核が形成されやすくなる。結晶核が多数生成するほど結晶の析出起点が増加し、微細なリン酸塩結晶が析出する。
リン酸処理液を攪拌しながらめっき層に接触させることも、微細なリン酸塩結晶を析出させる有効な方法である。攪拌によりめっき層表面に常に新液が供給され、めっき層の成分が溶解することによるpH上昇が抑えられ、反応性が高位に維持される。スプレー方式でリン酸処理液をめっき層表面に供給することによっても、微細なリン酸塩結晶が析出する。
When a molten Zn—Al—Mg alloy-plated steel sheet is treated with a phosphoric acid treatment solution heated to 40 ° C. or higher, phosphate crystal nuclei are easily formed on the surface of the plating layer because of high reactivity. As the number of crystal nuclei is increased, the crystal starting point increases and fine phosphate crystals are precipitated.
Bringing the phosphoric acid treatment solution into contact with the plating layer while stirring is also an effective method for precipitating fine phosphate crystals. By stirring, a new solution is always supplied to the surface of the plating layer, the increase in pH due to dissolution of the components of the plating layer is suppressed, and the reactivity is maintained at a high level. Fine phosphate crystals are also deposited by supplying a phosphating solution to the surface of the plating layer by spraying.
リン酸処理液の温度や攪拌強度は、リン酸塩結晶の平均粒径が0.5〜5.0μm,平均食込み深さが0.05μm以上となるように調整される。食込み深さは、クロム酸二アンモニウム水溶液でリン酸塩結晶のみを溶解した後、走査型レーザ顕微鏡を用いて表面にあるリン酸塩結晶の痕跡を観察し、痕跡の深さを測定することにより求められる。食込み深さが0.05μm以上になると、リン酸塩結晶の密着性が十分になり成形加工時にリン酸塩処理鋼板から脱落しなくなる。しかし、5.0μmを超える食込み深さではめっき溶解量が多くなりすぎ、リン酸塩処理液の安定性も低下する。 The temperature and stirring strength of the phosphoric acid treatment solution are adjusted so that the average particle diameter of the phosphate crystals is 0.5 to 5.0 μm and the average bite depth is 0.05 μm or more. The biting depth is obtained by dissolving the phosphate crystals only with diammonium chromate aqueous solution, then observing the traces of phosphate crystals on the surface using a scanning laser microscope, and measuring the depth of the traces. Desired. When the biting depth is 0.05 μm or more, the adhesion of the phosphate crystals is sufficient and the phosphatized steel sheet does not fall off during the forming process. However, if the biting depth exceeds 5.0 μm, the amount of dissolution of the plating becomes too large, and the stability of the phosphating solution is also lowered.
塗装後の密着性や耐食性を確保する上では平均粒径:0.5μm以上のリン酸塩結晶が好ましいが、平均粒径が5.0μmを超えると成型加工時の応力によりリン酸塩結晶の凝集破壊が懸念される。結晶粒径は、有機酸,多糖類等の反応抑制剤をリン酸塩処理液に添加することによっても調整できる。 In order to ensure adhesion and corrosion resistance after coating, a phosphate crystal having an average particle size of 0.5 μm or more is preferable. However, if the average particle size exceeds 5.0 μm, the phosphate crystal is affected by stress during molding. There is concern about cohesive failure. The crystal grain size can also be adjusted by adding reaction inhibitors such as organic acids and polysaccharides to the phosphating solution.
リン酸塩処理時に析出するNi,Co,Fe,Mnの量をNi,Co,Feで0.05〜5.0mg/m2,Mnで0.05〜30mg/m2の範囲に管理している。0.05mg/m2以上の析出量で反応性の向上がみられ、根の深いリン酸塩結晶が析出しやすくなる。しかし、Ni,Co,Feで5.0mg/m2を超える析出量,Mnで30mg/m2を超える析出量になると、過剰量の貴な金属又はMn化合物が残存することになるのでリン酸塩皮膜の耐食性低下が懸念される。
リン酸塩皮膜は、めっき層最表面の被覆率が50面積%以上となるように形成することが好ましい。リン酸塩皮膜3の被覆率は膜厚やリン酸塩結晶2のサイズに影響されるが、50面積%以上でリン酸塩皮膜3を設けることにより十分な塗膜密着性,塗装後耐食性が得られる。
The amount of Ni, Co, Fe and Mn precipitated during phosphating is controlled in the range of 0.05 to 5.0 mg / m 2 for Ni, Co and Fe and 0.05 to 30 mg / m 2 for Mn. Yes. Reactivity is improved at a precipitation amount of 0.05 mg / m 2 or more, and a deep-root phosphate crystal is likely to precipitate. However, if the amount of precipitation exceeds 5.0 mg / m 2 for Ni, Co, and Fe and the amount of precipitation exceeds 30 mg / m 2 for Mn, an excessive amount of noble metal or Mn compound will remain, so phosphoric acid. There is concern about a decrease in the corrosion resistance of the salt film.
The phosphate film is preferably formed so that the coverage of the outermost surface of the plating layer is 50 area% or more. The coverage of the
リン酸塩皮膜を形成した後、Crフリー化成処理液で溶融Zn-Al-Mg合金めっき鋼板を処理する。Crフリー化成処理液自体は、本発明者等が特許第3305703号で紹介した処理液を使用でき、可溶性ハロゲン化物又は酸素酸塩をバルブメタルのソースとして含んでいる。バルブメタルには、Ti,Zr,Hf,V,Nb,Ta,Mo,Wから選ばれた1種又は2種以上の金属がある。たとえば、Tiのフッ化物はTiソース,Fソースとしても有効であるが、(NH4)F等の可溶性フッ化物をCrフリー化成処理液に別途添加しても良い。Ti以外のバルブメタルについても同様であるが、以下ではTiを例にとって説明する。 After forming the phosphate film, the molten Zn—Al—Mg alloy plated steel sheet is treated with a Cr-free chemical conversion treatment solution. The Cr-free chemical conversion treatment solution itself can use the treatment solution introduced by the present inventors in Patent No. 3305703, and contains a soluble halide or oxyacid salt as a source of valve metal. The valve metal includes one or more metals selected from Ti, Zr, Hf, V, Nb, Ta, Mo, and W. For example, although a fluoride of Ti is effective as a Ti source and an F source, a soluble fluoride such as (NH 4 ) F may be added separately to the Cr-free chemical conversion treatment solution. The same applies to valve metals other than Ti, but Ti will be described below as an example.
Crフリー化成処理液は、酸化チタン又は水酸化チタン及びフッ化チタンとなるTiソースの他に、化成皮膜のネットワークを形成する樹脂成分を含み、必要に応じキレート作用のある有機酸,金属リン酸塩又は複合リン酸塩,各種顔料,潤滑剤を配合しても良い。
Tiソースとしては、KnTiF6(K:アルカリ金属又はアルカリ土類金属,n:1又は2),K2[TiO(COO)2],(NH4)2TiF6,TiCl4,TiOSO4,Ti(SO4)2,Ti(OH)4等がある。Tiソースは、化成処理液を塗布した後で乾燥・焼付けするときに所定組成の酸化物又は水酸化物とフッ化物からなる化成皮膜が形成されるように各成分の配合比率が選定される。
The Cr-free chemical conversion treatment solution contains a resin component that forms a network of a chemical conversion film in addition to a Ti source that becomes titanium oxide or titanium hydroxide and titanium fluoride, and if necessary, an organic acid or metal phosphoric acid having a chelating action You may mix | blend salt or composite phosphate, various pigments, and a lubricant.
The Ti source, K n TiF 6 (K: an alkali metal or alkaline earth metal, n: 1 or 2), K 2 [TiO ( COO) 2], (NH 4) 2 TiF 6, TiCl 4, TiOSO 4 , Ti (SO 4 ) 2 , Ti (OH) 4 and the like. In the Ti source, the blending ratio of each component is selected so that a chemical conversion film composed of oxide or hydroxide and fluoride having a predetermined composition is formed when the chemical conversion treatment liquid is applied and then dried and baked.
化成皮膜の樹脂マトリックスを形成する成分として、ウレタン系、エポキシ系、ポリエチレン,ポリプロピレン,エチレン−アクリル酸共重合体等のオレフィン系、ポリスチレン等のスチレン系、ポリエステル系、或いはこれらの共重合体又は変性物、アクリル系等の有機樹脂を化成処理液に添加している。 Components that form the resin matrix of the conversion coating include olefins such as urethane, epoxy, polyethylene, polypropylene, and ethylene-acrylic acid copolymers, styrenes such as polystyrene, polyesters, and copolymers or modifications thereof. Organic resins such as products and acrylics are added to the chemical conversion treatment liquid.
ウレタン樹脂としては、有機ポリイソシアネート化合物とポリオール化合物とを反応させて得られる水溶性又は水分散性のウレタン樹脂、なかでも自己乳化型ウレタン樹脂が好ましい。有機ポリイソシアネート化合物としては、フェニレンジイソシアネート,トリレンジイソシアネート,ジフェニルメタンジイソシアネート,ナフタレンジイソシアネート等の脂肪族ジイソシアネート、シクロヘキサンジイソシアネート,イソホロンジイソシアネート,ノルボルナンジイソシアネート,キシリレンジイソシアネート,テトラメチルキシリレンジイソシアネート等の脂環族ジイソシアネートが挙げられる。他方、ポリオール化合物としては、ポリエステルポリオール,ポリエーテルポリオール,ポリカーボネートポリオール,ポリアセタールポリオール,ポリアクリレートポリオール,ポリエステルアミドポリオール,ポリブタジエン系等のポリオレフィンポリオールが挙げられる。 As the urethane resin, a water-soluble or water-dispersible urethane resin obtained by reacting an organic polyisocyanate compound and a polyol compound, particularly a self-emulsifying urethane resin is preferable. Examples of organic polyisocyanate compounds include aliphatic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate, alicyclic diisocyanates such as cyclohexane diisocyanate, isophorone diisocyanate, norbornane diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate. Can be mentioned. On the other hand, examples of the polyol compound include polyester polyols, polyether polyols, polycarbonate polyols, polyacetal polyols, polyacrylate polyols, polyester amide polyols, and polybutadiene-based polyolefin polyols.
自己乳化型のウレタン樹脂は、カルボン酸含有化合物等の親水成分を分子中に導入することによって作製される。自己乳化型ウレタン樹脂では,導入した親水成分に応じてイオン性がアニオン,カチオン又はノニオンになる。たとえば、ポリエチレングリコール,イソシアネート等をポリマー骨格に導入するとノニオン性に、水酸基を導入するとアニオン性に、スルホン酸(塩)基,カルボキシル(塩)基等を導入するとカチオン性になる。
リン酸塩を含む化成処理液やオキシカルボン酸やシランカップリング剤が添加された系では、アニオン性又はカチオン性ウレタン樹脂は樹脂粒子が凝集反応を起こしてゲル化することがあるが、ノニオン性ウレタン樹脂ではこのような現象が生じない。この点、ノニオン性ウレタン樹脂の使用が好ましいが、ノニオン性ウレタン樹脂の使用比率を半分以上とすることによりゲル化を起こすことなくアニオン性又はカチオン性ウレタン樹脂も使用できる。
The self-emulsifying urethane resin is produced by introducing a hydrophilic component such as a carboxylic acid-containing compound into the molecule. In the self-emulsifying urethane resin, the ionicity becomes an anion, a cation or a nonion depending on the introduced hydrophilic component. For example, when polyethylene glycol, isocyanate or the like is introduced into the polymer skeleton, it becomes nonionic, when a hydroxyl group is introduced, it becomes anionic, and when a sulfonic acid (salt) group, carboxyl (salt) group or the like is introduced, it becomes cationic.
In a system to which a chemical conversion treatment solution containing phosphate, an oxycarboxylic acid or a silane coupling agent is added, anionic or cationic urethane resin may cause gelation due to aggregation reaction of resin particles, but it is nonionic. Such a phenomenon does not occur in the urethane resin. In this respect, the use of a nonionic urethane resin is preferred, but an anionic or cationic urethane resin can be used without causing gelation by setting the use ratio of the nonionic urethane resin to half or more.
Tiソースを化成処理液中にイオンとして安定的に維持する上で、キレート作用のある有機酸を添加することが好ましい。有機酸を添加する場合、金属イオンをキレート化して化成処理液を安定させることから、有機酸/金属イオンのモル比が0.02以上となる添加量に定められる。有機酸としては、酒石酸,タンニン酸,クエン酸,蓚酸,マロン酸,乳酸,酢酸等が挙げられる。なかでも、酒石酸等のオキシカルボン酸やタンニン酸等の多価フェノール類は、処理液を安定化させると共に、フッ化物の自己修復作用を補完する作用も呈し、塗膜密着性の向上にも有効である。 In order to stably maintain the Ti source as ions in the chemical conversion solution, it is preferable to add an organic acid having a chelating action. In the case of adding an organic acid, metal ions are chelated to stabilize the chemical conversion solution, so that the organic acid / metal ion molar ratio is set to 0.02 or more. Examples of the organic acid include tartaric acid, tannic acid, citric acid, succinic acid, malonic acid, lactic acid, acetic acid and the like. Among them, polyphenols such as tartaric acid and other oxycarboxylic acids and tannic acid stabilize the treatment liquid and also complement the self-healing action of fluoride, which is also effective in improving coating film adhesion. It is.
任意成分としての可溶性又は難溶性金属リン酸塩又は複合リン酸塩を化成皮膜に含ませるため、各種金属のオルソリン酸塩やポリリン酸塩を添加してもよい。
可溶性金属リン酸塩又は複合リン酸塩は、化成皮膜から溶出して皮膜欠陥部に溶出し、めっき層と反応して不溶性リン酸塩を析出することによって、チタンフッ化物の自己修復作用を補完する。また、可溶性リン酸塩が解離する際に雰囲気が若干酸性化するため、チタンフッ化物の加水分解、ひいては難溶性チタン酸化物又は水酸化物の生成が促進される。可溶性リン酸塩又は複合リン酸塩を生成する金属にはアルカリ金属,アルカリ土類金属,Mn等があり、各種金属リン酸塩又は各種金属塩とリン酸,ポリリン酸,リン酸塩として化成処理液に添加される。
In order to include a soluble or poorly soluble metal phosphate or composite phosphate as an optional component in the chemical conversion film, orthophosphates and polyphosphates of various metals may be added.
Soluble metal phosphate or composite phosphate is eluted from the chemical conversion film and eluted in the film defect, and reacts with the plating layer to precipitate insoluble phosphate, thereby complementing the self-healing action of titanium fluoride. . Further, since the atmosphere is slightly acidified when the soluble phosphate is dissociated, the hydrolysis of titanium fluoride, and hence the generation of hardly soluble titanium oxide or hydroxide, is promoted. Metals that produce soluble phosphates or composite phosphates include alkali metals, alkaline earth metals, Mn, etc., various metal phosphates or various metal salts and chemical conversion treatment as phosphoric acid, polyphosphoric acid, phosphate Added to the liquid.
難溶性の金属リン酸塩又は複合リン酸塩は、化成皮膜に分散し、皮膜欠陥を解消すると共に皮膜強度を向上させる。難溶性リン酸塩又は複合リン酸塩を形成する金属にはAl,Ti,Zr,Hf,Zn等があり、各種金属リン酸塩又は各種金属塩とリン酸,ポリリン酸,リン酸塩として化成処理液に添加される。 The hardly soluble metal phosphate or composite phosphate is dispersed in the chemical conversion film to eliminate film defects and improve the film strength. There are Al, Ti, Zr, Hf, Zn, etc. as metals that form poorly soluble phosphates or composite phosphates. Various metal phosphates or various metal salts and phosphoric acid, polyphosphoric acid, and phosphate Added to the treatment solution.
Zn,Mn,Mg,Ca等の酸化物,水酸化物,リン酸塩,フッ化物,炭酸塩,有機酸塩を添加したリン酸塩処理液を使用すると、処理液中からZn,Mn,Mg,Ca等の金属がリン酸塩結晶2に取り込まれる。Zn,Mn,Mg,Ca等の金属成分を含まないリン酸塩処理液で形成されたリン酸塩結晶2がリン酸亜鉛単独のホパイト〔Zn3(PO4)・4H2O〕であるのに対し、Zn,Mn,Mg,Ca等を取り込んだリン酸塩結晶はめっき層に対する密着性,耐水性に優れた複合リン酸塩となり、耐食性の向上に有効なリン酸塩皮膜3を形成する。
When a phosphate treatment liquid to which oxides, hydroxides, phosphates, fluorides, carbonates, organic acid salts such as Zn, Mn, Mg, and Ca are added is used, Zn, Mn, Mg is added from the treatment liquid. , Ca and the like are incorporated into the
リン酸塩皮膜を形成した後、クロムフリー化成処理液で溶融Zn-Al-Mg合金めっき鋼板を処理する。クロムフリー化成処理液は、ハロゲン化物や酸素酸塩からなるバルブメタルのソース化合物及び樹脂マトリックス形成用の樹脂を含む処理液をベースとし、必要に応じてイオン安定化作用のある有機酸や、チタンフッ化物の自己修復作用を補完し耐食性を向上させるリン酸塩を配合している。 After forming the phosphate film, the molten Zn—Al—Mg alloy plated steel sheet is treated with a chromium-free chemical conversion treatment solution. The chromium-free chemical conversion treatment liquid is based on a treatment liquid containing a valve metal source compound composed of a halide or an oxyacid salt and a resin for forming a resin matrix, and if necessary, an organic acid having an ion stabilizing action or titanium fluoride. Contains phosphate that complements the self-healing action of the chemicals and improves corrosion resistance.
化成処理液には、顔料,潤滑剤となる成分を配合しても良い。
顔料には、酸化チタン,カーボンブラック,炭化カルシウム,アルミナ,酸化亜鉛等の無機顔料やフタロシアニン顔料等の有機顔料がある。顔料を添加する場合、3〜30質量%の範囲で配合量を選定する。顔料配合による着色効果は3質量%以上でみられるが、30質量%を超える過剰量の顔料を配合すると化成皮膜が多孔質化して耐食性が低下する。 化成処理液には、顔料,潤滑剤となる成分を配合しても良い。
You may mix | blend the component used as a pigment and a lubricant with a chemical conversion liquid.
Examples of the pigment include inorganic pigments such as titanium oxide, carbon black, calcium carbide, alumina, and zinc oxide, and organic pigments such as a phthalocyanine pigment. When adding a pigment, a compounding quantity is selected in the range of 3-30 mass%. The coloring effect due to the blending of the pigment is observed at 3% by mass or more. However, when an excessive amount of the pigment exceeding 30% by mass is blended, the chemical conversion film becomes porous and the corrosion resistance decreases. You may mix | blend the component used as a pigment and a lubrication agent with a chemical conversion liquid.
潤滑性の向上に有効なワックスを化成皮膜に含ませるため、フッ素系,ポリエチレン系,スチレン系等の有機ワックスやシリカ,二硫化モリブデン,タルク等の無機質潤滑剤等を添加することもできる。低融点の有機ワックスは、皮膜乾燥時に表面にブリードし、潤滑性を発現すると考えられる。高融点有機ワックスや無機系潤滑剤は、皮膜中に分散状態で存在するが,処理皮膜の最表層では島状分布で皮膜表面に露出することによって潤滑性が発現するものと考えられる。 In order to include a wax effective for improving lubricity in the chemical conversion film, organic waxes such as fluorine, polyethylene, and styrene, inorganic lubricants such as silica, molybdenum disulfide, and talc can be added. The low melting point organic wax is considered to bleed on the surface when the film is dried and to exhibit lubricity. High melting point organic waxes and inorganic lubricants are present in a dispersed state in the film, but it is considered that lubricity is manifested by exposure to the film surface in an island-like distribution in the outermost layer of the treated film.
以上のように、ハロゲン化物や酸素酸塩からなるTiソース化合物及び樹脂マトリックス形成用の樹脂を含む処理液をベースとし、必要に応じてイオン安定化作用のある有機酸や、チタンフッ化物の自己修復作用を補完し耐食性を向上させる作用のあるリン酸塩を配合する。
調製された処理液をリン酸塩処理された溶融Zn-Al-Mg合金めっき鋼板に塗布すると、フッ素イオンとめっき層1又はTiと反応した界面反応層4aがリン酸塩結晶2の間にあるめっき層1の露出表面に優先的に形成される(図2)。界面反応層4aは、リン酸塩結晶2のないめっき層1に析出する場合に比較して成長が促進され、自己修復作用のあるフッ化チタンを十分な量含む層となる。界面反応層4aの厚みは、化成処理液に含まれるバルブメタルソースの濃度で調整できる。また、化成処理液や原板を保温して反応性を高めることによっても、界面反応層4aが厚く成長する。
As described above, based on treatment liquid containing Ti source compound consisting of halide or oxyacid salt and resin for forming resin matrix, self-healing of organic acid and ion fluoride with ion stabilizing action as required The phosphate which supplements an effect | action and has the effect | action which improves corrosion resistance is mix | blended.
When the prepared treatment liquid is applied to a phosphate-treated hot-dip Zn—Al—Mg alloy-plated steel sheet, an interfacial reaction layer 4 a that reacts with fluorine ions and the
界面反応層4aは、リン酸塩結晶2で分断されているので加工時等に加えられる応力が分散されるため、めっき層1に対する密着性も低下しない。しかも、めっき層1から突出しているリン酸塩結晶2の大半が界面反応層4aで覆われることなく、Tiのフッ化物,酸化物,水酸化物やリン酸塩が分散した有機樹脂皮膜4bが界面反応層4aの上に形成されるため、塗装後耐食性,塗膜密着性,接着剤に対する密着性が格段に向上する。
Crフリー化成処理液をロールコート法,スピンコート法,スプレー法等で化成処理用原板に塗布し、水洗することなく乾燥することによって、塗膜密着性,塗装後耐食性に優れた化成皮膜がめっき層の表層に形成される。Crフリー化成処理液の塗布量は、十分な耐食性を確保するため0.1mg/m2以上のチタン付着量となるように調整することが好ましい。
Since the interface reaction layer 4a is divided by the
A Cr-free chemical conversion treatment solution is applied to a chemical conversion treatment original plate by roll coating, spin coating, spraying, etc., and dried without washing with water, so that a coating with excellent coating adhesion and corrosion resistance after coating is plated. It is formed on the surface layer of the layer. The coating amount of the Cr-free chemical conversion treatment liquid is preferably adjusted so that the amount of titanium adhered is 0.1 mg / m 2 or more in order to ensure sufficient corrosion resistance.
形成された化成皮膜を蛍光X線,ESCA等で元素分析すると、化成皮膜に含まれているO及びF濃度が測定される。測定値から算出した濃度比F/O(原子比率)と耐食性との関係を調査したところ、濃度比F/O(原子比率)1/100以上で皮膜欠陥部を起点とする腐食の発生が大幅に減少した。これは、自己修復作用のあるチタンフッ化物が十分な量で化成皮膜中に含まれていることによるものと推察される。 When the formed chemical conversion film is subjected to elemental analysis by fluorescent X-ray, ESCA, etc., the O and F concentrations contained in the chemical conversion film are measured. When the relationship between the concentration ratio F / O (atomic ratio) calculated from the measured values and the corrosion resistance was investigated, the occurrence of corrosion starting from the film defects was significantly observed at a concentration ratio F / O (atomic ratio) of 1/100 or more. Decreased. This is presumably due to the fact that a sufficient amount of titanium fluoride having a self-repairing action is contained in the chemical conversion film.
界面反応層,有機樹脂系皮膜は、それぞれ5〜300nm,0.1〜3μm程度の厚みをもっていることが好ましい。界面反応層は、膜厚5nm以上で十分な環境遮断能を、10nm以上で良好な防食能を発現するが、300nmを超える厚膜に成長すると成形加工時に加わる応力によってクラックが発生しやすくなり、却って耐食性を低下させる。界面反応層への腐食性成分の到達は、膜厚0.1μm以上の化成皮膜で顕著に抑制される。しかし、膜厚が3μmを超える化成皮膜では、耐食性向上効果が飽和するばかりでなく、溶接性が劣化する。なお、界面反応層や有機樹脂系皮膜の厚みは、AESによる深さ方向の元素分析,TEM観察等によって測定できる。 It is preferable that the interface reaction layer and the organic resin film have thicknesses of about 5 to 300 nm and 0.1 to 3 μm, respectively. The interfacial reaction layer expresses sufficient environmental barrier ability at a film thickness of 5 nm or more and good anticorrosion ability at 10 nm or more, but when it grows to a thick film exceeding 300 nm, cracks are likely to occur due to stress applied during molding processing, On the contrary, it reduces the corrosion resistance. The arrival of the corrosive component to the interface reaction layer is remarkably suppressed by a chemical conversion film having a thickness of 0.1 μm or more. However, a chemical conversion film having a film thickness exceeding 3 μm not only saturates the effect of improving corrosion resistance but also deteriorates weldability. Note that the thickness of the interface reaction layer and the organic resin film can be measured by elemental analysis in the depth direction by AES, TEM observation, and the like.
溶融Zn-Al-Mg合金めっき鋼板に塗布したCrフリー化成処理液を常温で乾燥することもできるが、連続操業を考慮すると80℃以上に保持して乾燥時間を短縮することが好ましい。ただし、250℃を超える乾燥温度では、化成処理被膜に含まれている有機成分が熱分解し、有機成分で付与された特性が損なわれることがある。
化成皮膜を形成した後、更に耐食性に優れた有機皮膜を形成することもできる。この種の皮膜として、たとえばウレタン系樹脂,エポキシ樹脂,ポリエチレン、ポリプロピレン,エチレン−アクリル酸共重合体等のオレフィン系樹脂,ポリスチレン等のスチレン系樹脂,ポリエステル,或いはこれらの共重合物又は変性物,アクリル系樹脂等の樹脂皮膜を膜厚0.1〜5μmで化成皮膜の上に設けると、クロメート皮膜を凌駕する高耐食性が得られる。或いは、導電性に優れた樹脂皮膜を化成皮膜の上に設けることにより、潤滑性が改善され、溶接性も付与される。この種の樹脂皮膜としては、たとえば有機樹脂エマルジョンを静電霧化して塗布する方法で形成できる。
The Cr-free chemical conversion treatment liquid applied to the molten Zn—Al—Mg alloy-plated steel sheet can be dried at room temperature, but considering continuous operation, it is preferable to keep the temperature at 80 ° C. or higher to shorten the drying time. However, when the drying temperature exceeds 250 ° C., the organic component contained in the chemical conversion coating is thermally decomposed, and the properties imparted with the organic component may be impaired.
After forming the chemical conversion film, an organic film having further excellent corrosion resistance can be formed. As this type of film, for example, urethane resin, epoxy resin, polyethylene, polypropylene, olefin resin such as ethylene-acrylic acid copolymer, styrene resin such as polystyrene, polyester, or a copolymer or modified product thereof, When a resin film such as an acrylic resin is provided on the chemical film with a film thickness of 0.1 to 5 μm, high corrosion resistance surpassing that of the chromate film can be obtained. Alternatively, by providing a resin film having excellent conductivity on the chemical conversion film, lubricity is improved and weldability is also imparted. This type of resin film can be formed by, for example, applying an organic resin emulsion by electrostatic atomization.
原板として、Al:6.0質量%,Mg:3.1質量%,Zn:残部の合金めっき層が片面当り付着量:75g/m2で形成された板厚:0.7mmの溶融Zn-Al-Mg合金めっき鋼板を使用した。合金めっき層を顕微鏡観察すると、微細な〔Al/Zn/Zn2Mgの三元共晶組織〕が75面積%以上の割合で観察された。 As an original plate, Al: 6.0% by mass, Mg: 3.1% by mass, Zn: the remaining alloy plating layer formed with an adhesion amount per side of 75 g / m 2 : Plate thickness: 0.7 mm Molten Zn— An Al—Mg alloy plated steel sheet was used. When the alloy plating layer was observed with a microscope, fine [Al / Zn / Zn 2 Mg ternary eutectic structure] was observed at a ratio of 75 area% or more.
リン酸塩処理液(表1)を用いて各めっき鋼板をリン酸塩処理した後、クロムフリー化成処理液(表2)を塗布し乾燥することによりリン酸塩皮膜をクロムフリー化成皮膜でシーリングした。リン酸塩処理とクロムフリー化成処理の組合せを表3に、亜鉛系めっき鋼板の表面に形成されたリン酸塩皮膜,クロムフリー化成皮膜を表4に示す。表4中、リン酸塩皮膜の食込み深さは、クロム酸二アンモニウム水溶液でリン酸塩結晶のみを溶解除去した後、リン酸塩結晶の痕跡部を走査型レーザ顕微鏡で観察し、20ヶ所の痕跡の深さを平均化した値で示す。 After each galvanized steel sheet is phosphated using a phosphating solution (Table 1), the chrome-free conversion coating solution (Table 2) is applied and dried to seal the phosphate coating with a chrome-free conversion coating. did. Table 3 shows combinations of phosphate treatment and chromium-free chemical conversion treatment, and Table 4 shows phosphate coatings and chromium-free chemical conversion coatings formed on the surface of galvanized steel sheets. In Table 4, the depth of penetration of the phosphate film was determined by observing traces of phosphate crystals with a scanning laser microscope after dissolving and removing only phosphate crystals with an aqueous diammonium chromate solution. The average depth of the trace is shown.
得られた化成処理鋼板から試験片を切り出し、各種腐食試験に供した。
〔平坦部腐食試験〕
試験片の端面をシールし、JIS Z2371に準拠して35℃の5%NaCl水溶液を試験片表面に噴霧した。塩水噴霧を72時間又は240時間継続した後、試験片表面を観察し白錆発生状況を調査した。試験片表面に占める白錆の面積占有率が5面積%未満を◎,5〜10面積%を○,10〜30面積%を△,30〜50面積%を▲,50面積%以上を×として平坦部耐食性を評価した。
A test piece was cut out from the obtained chemical conversion treated steel sheet and subjected to various corrosion tests.
[Flat corrosion test]
The end face of the test piece was sealed, and a 5% NaCl aqueous solution at 35 ° C. was sprayed on the test piece surface in accordance with JIS Z2371. After spraying salt water for 72 hours or 240 hours, the surface of the test piece was observed to investigate the occurrence of white rust. The area occupancy ratio of white rust on the surface of the test piece is less than 5 area%, ◎, 5-10 area% is ◯, 10-30 area% is △, 30-50 area% is ▲, and 50 area% or more is x. The flat part corrosion resistance was evaluated.
〔加工部腐食試験〕
リン酸塩皮膜が部分的に損傷を受ける180度曲げ加工を施した試験片について,平坦部腐食試験と同じ塩水噴霧を24時間,120時間継続し、加工部に発生した白錆の面積占有率を求めた。面積占有率が5面積%未満を◎,5〜10面積%を○,10〜30面積%を△,30〜50面積%を▲,50面積%以上を×として加工部耐食性を評価した。
[Processed part corrosion test]
The test piece subjected to 180-degree bending work that partially damaged the phosphate coating was subjected to the same salt spray as the flat part corrosion test for 24 hours and 120 hours, and the area occupancy rate of white rust generated in the processed part Asked. The area occupancy rate was evaluated as corrosion resistance of a processed part, where を is less than 5%, 5〜 is 5 to 10%, △ is 10 to 30%, ▲ is 30 to 50% and x is 50% or more.
〔塗装後腐食試験〕
化成処理鋼板をメラミンアルキッド塗装し、膜厚30μmの塗膜を形成した。塗膜にクロスカットを入れ、1000時間の塩水噴霧に供した後、クロスカット部に接着テープを貼り付け瞬時に引き剥がすテープ剥離試験し、塗膜が剥離した幅を腐食幅として測定した。腐食幅が2mm未満を◎,5mm未満を○,10mm未満を△,10mmを超える腐食幅を×として塗装後耐食性を評価した。
[Corrosion test after painting]
The chemical conversion treated steel sheet was coated with melamine alkyd to form a coating film having a thickness of 30 μm. After the crosscut was put into the coating film and subjected to salt water spraying for 1000 hours, a tape peeling test was performed in which an adhesive tape was applied to the crosscut portion and peeled off instantaneously, and the width at which the coating film was peeled was measured as the corrosion width. Corrosion resistance after coating was evaluated with ◎ when the corrosion width was less than 2 mm, ◯ when it was less than 5 mm, Δ when it was less than 10 mm, and x when the corrosion width was more than 10 mm.
表5の腐食試験結果にみられるように、リン酸塩処理後にクロムフリー化成処理した溶融Zn-Al-Mg合金めっき鋼板は、平坦部耐食性,加工部耐食性,塗装後耐食性の何れにも優れた特性を示した。なかでも、被覆率の高いリン酸塩皮膜とクロムフリー化成皮膜とを組み合わせた場合、加工部耐食性が格段と改善されており、クロムフリー化成皮膜の自己修復作用が発現していることが窺われる。 As can be seen from the corrosion test results in Table 5, the hot-dip Zn-Al-Mg alloy-plated steel sheet, which was chromium-free conversion-treated after phosphate treatment, was excellent in all of flat part corrosion resistance, processed part corrosion resistance, and post-coating corrosion resistance. The characteristics are shown. In particular, when a phosphate coating with a high coating rate and a chromium-free chemical coating are combined, the corrosion resistance of the processed parts is remarkably improved, and the self-healing action of the chromium-free chemical coating is expressed. .
他方、リン酸塩処理せずにクロムフリー化成皮膜を設けた試験No.19,20や、Ti(バルブメタル)を含まない試験No.13,14では、平坦部耐食性,塗装後耐食性に劣り、塩水噴霧が長期になるほど平坦部,加工部共に白錆発生が助長された。バルブメタルのフッ化物を含まないクロムフリー化成皮膜を形成した試験No.15,16でも、塩水噴霧が長期になると平坦部に多量の白錆が発生した。リン酸塩処理をクロメート処理でシーリングする従来の化成処理を施した試験No.17,18では、短時間の塩水噴霧によっても加工部に白錆が発生し、平坦部耐食性,塗装後耐食性も十分でなかった。 On the other hand, in tests No. 19 and 20 in which a chromium-free chemical conversion film was provided without phosphating, and tests No. 13 and 14 that did not contain Ti (valve metal), the flat portion corrosion resistance and post-coating corrosion resistance were inferior. The longer the salt spray, the more the white rust was generated in the flat and processed parts. Even in Test Nos. 15 and 16 in which a chromium-free chemical conversion film containing no valve metal fluoride was formed, a large amount of white rust was generated on the flat portion when salt spray was applied for a long time. In tests No. 17 and 18 with the conventional chemical conversion treatment that seals the phosphate treatment with chromate treatment, white rust is generated in the processed part even by a short salt spray, and the flat part corrosion resistance and corrosion resistance after painting are sufficient. It was not.
更に、リン酸塩皮膜,クロムフリー化成皮膜を設けた溶融Zn-Al-Mg合金めっき鋼板にエポキシ系接着剤を用いて膜厚:300μmのPETフィルムを貼り合わせた。
得られたラミネート鋼板について、ドロービード摺動変形試験(荷重:200kgf)後に引張り試験してフィルムの剥離強度を測定した。めっき層に対するリン酸塩結晶の食込み深さで測定結果を整理したところ、リン酸塩結晶の平均食込み深さが0.05μm以上になると80N/20mmを超える高い剥離強度を示した(図3)。リン酸塩結晶の結晶サイズと剥離強度との関係では、リン酸塩結晶の平均粒径を5.0μm以下にすることにより、高い剥離強度でPETフィルムが貼り合わされていることが確認された(図4)。図3,4の結果から、リン酸塩結晶の平均粒径を0.5〜5.0μmの範囲に、平均食込み深さを0.05μm以上にすることが有効であることが理解できる。
メラミンアルキッド樹脂塗料を用い、膜厚:25μmの塗膜を加工後の化成処理鋼板に設けた場合でも、同様に平均粒径:0.5〜5.0μm,平均食込み深さ:0.05μm以上のリン酸塩結晶が形成されているので、密着性に優れた塗膜が形成された。
Furthermore, a PET film having a film thickness of 300 μm was bonded to a molten Zn—Al—Mg alloy-plated steel sheet provided with a phosphate film and a chromium-free chemical conversion film using an epoxy adhesive.
The obtained laminated steel sheet was subjected to a tensile test after a draw bead sliding deformation test (load: 200 kgf) to measure the peel strength of the film. When the measurement results were arranged by the penetration depth of the phosphate crystals with respect to the plating layer, when the average penetration depth of the phosphate crystals was 0.05 μm or more, a high peel strength exceeding 80 N / 20 mm was shown (FIG. 3). . Regarding the relationship between the crystal size of the phosphate crystals and the peel strength, it was confirmed that the PET film was bonded with a high peel strength by setting the average particle size of the phosphate crystals to 5.0 μm or less ( FIG. 4). From the results of FIGS. 3 and 4, it can be understood that it is effective to set the average grain size of phosphate crystals in the range of 0.5 to 5.0 μm and the average bite depth to 0.05 μm or more.
Even when a melamine alkyd resin coating is used and a coating film having a film thickness of 25 μm is provided on the chemically treated steel sheet after processing, the average particle diameter is similarly 0.5 to 5.0 μm, and the average biting depth is 0.05 μm or more. Thus, a coating film having excellent adhesion was formed.
表1のNo.1処理液を用いて実施例1と同じ原板をリン酸塩処理した。本実施例においては、リン酸塩処理に先立つ表面調整の条件やリン酸塩処理液の温度,処理時間を管理することにより、0.5〜5μmの範囲でリン酸塩結晶の平均高さを変化させたリン酸塩皮膜を形成した。クロムフリー化成処理には表2のNo.3処理液を用い、塗布量やロールコート条件を調整することにより界面反応層の厚みを変化させた化成皮膜を形成した。 The same original plate as in Example 1 was subjected to phosphate treatment using the No. 1 treatment solution shown in Table 1. In this example, the average height of the phosphate crystals in the range of 0.5 to 5 μm is controlled by controlling the surface conditioning conditions prior to the phosphate treatment, the temperature of the phosphate treatment solution, and the treatment time. An altered phosphate film was formed. For the chromium-free chemical conversion treatment, a No. 3 treatment solution shown in Table 2 was used, and a chemical conversion film having a changed thickness of the interfacial reaction layer was formed by adjusting the coating amount and roll coating conditions.
化成処理後の鋼板からサンプリングされた試験片にエポキシ系接着剤でPETフィルムをラミネートし、ドロービード摺動変形試験(荷重:200kgf)後の引張試験でフィルムの剥離強度を測定した。図5の測定結果にみられるように、何れのリン酸塩結晶の高さにおいても界面反応層が厚くなると剥離強度が低下する傾向があった。そして、めっき層から起立するリン酸塩結晶の平均高さに対して界面反応層の厚みを10%以下に規制するとき、良好な剥離強度を維持できることが判った。 A PET film was laminated with an epoxy adhesive on a test piece sampled from the steel sheet after chemical conversion treatment, and the peel strength of the film was measured by a tensile test after a draw bead sliding deformation test (load: 200 kgf). As can be seen from the measurement results in FIG. 5, the peel strength tends to decrease as the interface reaction layer becomes thicker at any phosphate crystal height. And when the thickness of the interface reaction layer was controlled to 10% or less with respect to the average height of the phosphate crystals rising from the plating layer, it was found that good peel strength can be maintained.
片面当り付着量が90g/m2一定でめっき層の組成が異なる複数のZn-Al-Mg合金めっき鋼板(板厚:0.8mm一定)を用意した。合金めっき層を顕微鏡観察すると、何れも微細な〔Al/Zn/Zn2Mgの三元共晶組織〕が80面積%以上の割合で観察された。
表6のリン酸塩処理液を用いて各めっき鋼板を液温:60℃,接触時間:5秒でリン酸塩処理した後、表2のNo.4化成処理液を塗布し乾燥することにより、リン酸塩皮膜をクロムフリー化成皮膜でシーリングした。クロムフリー化成皮膜は、バルブメタルのトータル付着量が30mg/m2,皮膜厚みが0.2μmであった。
A plurality of Zn—Al—Mg alloy-plated steel sheets (plate thickness: constant 0.8 mm) having a constant adhesion amount per side of 90 g / m 2 and different coating layer compositions were prepared. When the alloy plating layer was observed with a microscope, a fine [Al / Zn / Zn 2 Mg ternary eutectic structure] was observed at a ratio of 80 area% or more.
By subjecting each plated steel sheet to phosphate treatment at a liquid temperature of 60 ° C. and a contact time of 5 seconds using the phosphate treatment liquid of Table 6, the No. 4 chemical conversion treatment liquid of Table 2 is applied and dried. The phosphate coating was sealed with a chromium-free chemical conversion coating. The chromium-free chemical conversion film had a total valve metal deposition amount of 30 mg / m 2 and a film thickness of 0.2 μm.
めっき層の組成及びめっき層表面に形成したリン酸塩皮膜の組合せを表7に示す。
表7中、置換金属析出量は、次の手順で求めた。リン酸塩処理後のめっき鋼板から切り出した10cm×10cmの試験片を室温の二クロム酸アンモニウム水溶液(二クロム酸アンモニウム:20g/l,濃アンモニウム:480g/l)に15分浸漬してリン酸塩結晶を溶解させた後、試験片を室温の10%HCl水溶液に浸漬してめっき層ごと溶解し、溶解液のICP分析結果から置換金属析出量を算出した。また、リン酸塩結晶の食込み深さは、実施例1と同じ方法で測定した。
Table 7 shows the composition of the plating layer and the combination of the phosphate film formed on the surface of the plating layer.
In Table 7, the amount of substitutional metal precipitation was determined by the following procedure. A test piece of 10 cm × 10 cm cut out from the plated steel sheet after the phosphate treatment was immersed in an aqueous solution of ammonium dichromate (ammonium dichromate: 20 g / l, concentrated ammonium: 480 g / l) at room temperature for 15 minutes. After the salt crystals were dissolved, the test piece was immersed in a 10% aqueous HCl solution at room temperature to dissolve the entire plating layer, and the amount of displacement metal deposited was calculated from the ICP analysis result of the solution. Further, the penetration depth of the phosphate crystals was measured by the same method as in Example 1.
クロムフリー処理後のめっき鋼板から試験片を切り出し、実施例1と同じ各種腐食試験に供した。
表8の腐食試験結果にみられるように、各種組成のZn-Al-Mg合金めっき鋼板に本発明に従ったリン酸塩処理後、クロムフリー化成処理を施すと、平坦部耐食性,加工部耐食性,塗装後耐食性の何れにも優れた特性を示す塗装鋼板となることが確認される。
A test piece was cut out from the plated steel sheet after the chromium-free treatment and subjected to the same various corrosion tests as in Example 1.
As can be seen from the corrosion test results in Table 8, when the Zn-Al-Mg alloy-plated steel sheet of various compositions is subjected to the phosphate treatment according to the present invention and then subjected to chromium-free chemical conversion treatment, the flat part corrosion resistance and the processed part corrosion resistance are obtained. Thus, it is confirmed that the coated steel sheet exhibits excellent characteristics in both corrosion resistance after coating.
以上に説明したように、めっき層に基部が食い込んでめっき層から起立するリン酸塩結晶をリン酸塩処理で形成した後、界面反応層,有機樹脂系皮膜からなるクロムフリー化成皮膜でシーリングするとき、加工後においてもリン酸塩皮膜が良好な密着状態を維持する化成処理鋼板が得られる。しかも、有機樹脂系の化成処理皮膜を設けているため加工性も良好である。めっき層に食い込み化成処理皮膜から突出している酸塩皮膜を介して塗膜やラミネートフィルムが設けられるので塗膜密着性,フィルム密着性にも優れ、溶融Zn-Al-Mg合金めっき本来の高耐食性も活かされる。そのため、ユーザ側で製品形状に成形加工して塗装やラミネートする用途に適した鋼材として、外装材,内装材,表装材,車両用鋼板等として使用される。 As explained above, after forming a phosphate crystal that has a base bite into the plating layer and rising from the plating layer by phosphating, it is sealed with a chromium-free chemical conversion film consisting of an interface reaction layer and an organic resin film. In some cases, a chemically treated steel sheet is obtained in which the phosphate coating maintains a good adhesion state even after processing. In addition, since an organic resin-based chemical conversion film is provided, workability is also good. The coating layer and laminate film are provided through the acid salt film protruding from the chemical conversion coating that penetrates into the plating layer, so the coating film adhesion and film adhesion are excellent, and the original high corrosion resistance of the molten Zn-Al-Mg alloy plating Is also utilized. Therefore, it is used as an exterior material, an interior material, a cover material, a steel plate for vehicles, and the like as a steel material suitable for use in painting and laminating by processing into a product shape on the user side.
1:めっき層 2:リン酸塩結晶 3:Ni析出層 4:クロムフリー化成皮膜 4a:界面反応層 4b:有機樹脂系皮膜 5:粒状反応生成物
1: Plating layer 2: Phosphate crystal 3: Ni precipitation layer 4: Chromium-free chemical conversion film 4a:
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Citations (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS62284087A (en) * | 1986-06-03 | 1987-12-09 | Kawasaki Steel Corp | Surface-treated steel sheet having excellent coated film adhesion and its production |
JPH11350159A (en) * | 1998-06-05 | 1999-12-21 | Kobe Steel Ltd | Zinc phosphate-treated steel sheet excellent in peeling resistance and color tone |
JP2000160354A (en) * | 1998-11-20 | 2000-06-13 | Nkk Corp | Organic coated steel sheet excellent in corrosion resistance |
JP2000248367A (en) * | 1998-12-28 | 2000-09-12 | Nippon Steel Corp | Galvanized steel sheet with non-chromium type treatment |
JP2001105528A (en) * | 1999-08-02 | 2001-04-17 | Nkk Corp | Zinc phosphate composite treated steel panel |
JP2001172771A (en) * | 1999-10-08 | 2001-06-26 | Kawasaki Steel Corp | Surface treated galvanized steel sheet |
JP2001207270A (en) * | 2000-01-24 | 2001-07-31 | Nippon Parkerizing Co Ltd | Phosphate chemical conversion treating method for zinc- containing metal plated steel sheet |
JP2002187234A (en) * | 2000-12-21 | 2002-07-02 | Nisshin Steel Co Ltd | Non-chromium coated steel plate having excellent corrosion resistance |
JP2002194559A (en) * | 2000-12-21 | 2002-07-10 | Nisshin Steel Co Ltd | Chemical conversion coated steel sheet superior in corrosion resistance |
JP2002275653A (en) * | 2001-03-15 | 2002-09-25 | Kansai Paint Co Ltd | Metallic surface treated steel sheet |
JP2002317279A (en) * | 2001-04-17 | 2002-10-31 | Nisshin Steel Co Ltd | Coated steel sheet which has little environmental load using aqueous coating |
JP2005126812A (en) * | 2003-10-01 | 2005-05-19 | Nisshin Steel Co Ltd | Galvanized steel sheet superior in corrosion resistance, coating applicability and adhesiveness |
JP2005290551A (en) * | 2004-03-08 | 2005-10-20 | Nisshin Steel Co Ltd | Chemical conversion-treated steel sheet having excellent film adhesion after forming |
-
2005
- 2005-03-01 JP JP2005056184A patent/JP4579715B2/en active Active
Patent Citations (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS62284087A (en) * | 1986-06-03 | 1987-12-09 | Kawasaki Steel Corp | Surface-treated steel sheet having excellent coated film adhesion and its production |
JPH11350159A (en) * | 1998-06-05 | 1999-12-21 | Kobe Steel Ltd | Zinc phosphate-treated steel sheet excellent in peeling resistance and color tone |
JP2000160354A (en) * | 1998-11-20 | 2000-06-13 | Nkk Corp | Organic coated steel sheet excellent in corrosion resistance |
JP2000248367A (en) * | 1998-12-28 | 2000-09-12 | Nippon Steel Corp | Galvanized steel sheet with non-chromium type treatment |
JP2001105528A (en) * | 1999-08-02 | 2001-04-17 | Nkk Corp | Zinc phosphate composite treated steel panel |
JP2001172771A (en) * | 1999-10-08 | 2001-06-26 | Kawasaki Steel Corp | Surface treated galvanized steel sheet |
JP2001207270A (en) * | 2000-01-24 | 2001-07-31 | Nippon Parkerizing Co Ltd | Phosphate chemical conversion treating method for zinc- containing metal plated steel sheet |
JP2002187234A (en) * | 2000-12-21 | 2002-07-02 | Nisshin Steel Co Ltd | Non-chromium coated steel plate having excellent corrosion resistance |
JP2002194559A (en) * | 2000-12-21 | 2002-07-10 | Nisshin Steel Co Ltd | Chemical conversion coated steel sheet superior in corrosion resistance |
JP2002275653A (en) * | 2001-03-15 | 2002-09-25 | Kansai Paint Co Ltd | Metallic surface treated steel sheet |
JP2002317279A (en) * | 2001-04-17 | 2002-10-31 | Nisshin Steel Co Ltd | Coated steel sheet which has little environmental load using aqueous coating |
JP2005126812A (en) * | 2003-10-01 | 2005-05-19 | Nisshin Steel Co Ltd | Galvanized steel sheet superior in corrosion resistance, coating applicability and adhesiveness |
JP2005290551A (en) * | 2004-03-08 | 2005-10-20 | Nisshin Steel Co Ltd | Chemical conversion-treated steel sheet having excellent film adhesion after forming |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005290551A (en) * | 2004-03-08 | 2005-10-20 | Nisshin Steel Co Ltd | Chemical conversion-treated steel sheet having excellent film adhesion after forming |
JP4579714B2 (en) * | 2004-03-08 | 2010-11-10 | 日新製鋼株式会社 | Chemically treated steel sheet with excellent film adhesion after forming |
JP2007182600A (en) * | 2006-01-05 | 2007-07-19 | Nisshin Steel Co Ltd | Hot-dip zinc-plated steel sheet having excellent waterproof adhesivity of coating film |
EP2088223A1 (en) * | 2008-01-16 | 2009-08-12 | ThyssenKrupp Steel AG | Phosphated sheet metal and method for producing such a sheet metal |
WO2010089273A1 (en) * | 2009-02-06 | 2010-08-12 | Thyssenkrupp Steel Europe Ag | Method for producing a coated steel component by means of hot forming and steel component produced by means of hot forming |
JP2012082511A (en) * | 2010-09-15 | 2012-04-26 | Nisshin Steel Co Ltd | Hot-dip zinc-coated steel sheet showing black color |
JP2013060640A (en) * | 2011-09-14 | 2013-04-04 | Nisshin Steel Co Ltd | Chemical conversion-treated plated steel sheet and method for production thereof |
JP6064009B1 (en) * | 2015-08-28 | 2017-01-18 | 日新製鋼株式会社 | Manufacturing apparatus and manufacturing method of chromium-free chemical conversion coated steel sheet |
WO2017179665A1 (en) * | 2016-04-13 | 2017-10-19 | 新日鐵住金株式会社 | Treated surface steel band and method for manufacturing treated surface steel band |
JP6246984B1 (en) * | 2016-04-13 | 2017-12-13 | 新日鐵住金株式会社 | Surface-treated steel strip and method for producing surface-treated steel strip |
CN109072447A (en) * | 2016-04-13 | 2018-12-21 | 新日铁住金株式会社 | The manufacturing method of surface-treated steel strips and surface-treated steel strips |
CN109072447B (en) * | 2016-04-13 | 2020-09-01 | 日本制铁株式会社 | Surface-treated steel strip and method for producing surface-treated steel strip |
CN113897571A (en) * | 2021-09-29 | 2022-01-07 | 哈尔滨市中北热镀锌有限公司 | Process method for enhancing hot galvanizing adhesive force |
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