JPH04236752A - Production of iron-zinc alloy plated steel sheet having plural iron-zinc alloy plating layers having excellent electrodeposition coating suitability - Google Patents
Production of iron-zinc alloy plated steel sheet having plural iron-zinc alloy plating layers having excellent electrodeposition coating suitabilityInfo
- Publication number
- JPH04236752A JPH04236752A JP1480391A JP1480391A JPH04236752A JP H04236752 A JPH04236752 A JP H04236752A JP 1480391 A JP1480391 A JP 1480391A JP 1480391 A JP1480391 A JP 1480391A JP H04236752 A JPH04236752 A JP H04236752A
- Authority
- JP
- Japan
- Prior art keywords
- iron
- zinc alloy
- layer
- steel sheet
- plating layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 229910001297 Zn alloy Inorganic materials 0.000 title claims abstract description 82
- 238000007747 plating Methods 0.000 title claims abstract description 82
- KFZAUHNPPZCSCR-UHFFFAOYSA-N iron zinc Chemical compound [Fe].[Zn] KFZAUHNPPZCSCR-UHFFFAOYSA-N 0.000 title claims abstract description 77
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 76
- 239000010959 steel Substances 0.000 title claims abstract description 76
- 238000000576 coating method Methods 0.000 title claims abstract description 33
- 239000011248 coating agent Substances 0.000 title claims abstract description 32
- 238000004070 electrodeposition Methods 0.000 title claims abstract description 17
- 238000004519 manufacturing process Methods 0.000 title claims description 4
- 239000013078 crystal Substances 0.000 claims abstract description 15
- 238000009713 electroplating Methods 0.000 claims abstract description 9
- 230000003647 oxidation Effects 0.000 claims abstract description 9
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 9
- 239000010410 layer Substances 0.000 claims description 130
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 32
- 229910052742 iron Inorganic materials 0.000 claims description 16
- 238000005275 alloying Methods 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 12
- 238000010438 heat treatment Methods 0.000 claims description 10
- 229910052725 zinc Inorganic materials 0.000 claims description 8
- 239000011701 zinc Substances 0.000 claims description 8
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 7
- 239000000126 substance Substances 0.000 claims description 7
- 238000005246 galvanizing Methods 0.000 claims description 6
- 229910052782 aluminium Inorganic materials 0.000 claims description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 5
- 239000002344 surface layer Substances 0.000 claims description 5
- 239000012535 impurity Substances 0.000 claims description 4
- 230000007547 defect Effects 0.000 abstract description 17
- 230000000052 comparative effect Effects 0.000 description 8
- 229910019142 PO4 Inorganic materials 0.000 description 7
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 7
- 239000010452 phosphate Substances 0.000 description 7
- 239000003973 paint Substances 0.000 description 5
- 238000000465 moulding Methods 0.000 description 4
- 229910001335 Galvanized steel Inorganic materials 0.000 description 3
- 125000002091 cationic group Chemical group 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 239000008397 galvanized steel Substances 0.000 description 3
- 238000000227 grinding Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 239000007832 Na2SO4 Substances 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- VMHLLURERBWHNL-UHFFFAOYSA-M Sodium acetate Chemical compound [Na+].CC([O-])=O VMHLLURERBWHNL-UHFFFAOYSA-M 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000010960 cold rolled steel Substances 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 235000017281 sodium acetate Nutrition 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- NWONKYPBYAMBJT-UHFFFAOYSA-L zinc sulfate Chemical compound [Zn+2].[O-]S([O-])(=O)=O NWONKYPBYAMBJT-UHFFFAOYSA-L 0.000 description 1
- 229910000368 zinc sulfate Inorganic materials 0.000 description 1
- 239000011686 zinc sulphate Substances 0.000 description 1
- 235000009529 zinc sulphate Nutrition 0.000 description 1
Abstract
Description
【０００１】0001
【産業上の利用分野】この発明は、電着塗装性に優れた
、複数の鉄−亜鉛合金めっき層を有する鉄−亜鉛合金め
っき鋼板の製造方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an iron-zinc alloy plated steel sheet having a plurality of iron-zinc alloy plating layers and having excellent electrodeposition coating properties.
【０００２】0002
【従来の技術】合金化溶融亜鉛めっき鋼板には、電気亜
鉛めっき鋼板に比べて、めっき層を厚くすることが容易
であり、優れた耐食性が得られる利点がある。従って、
耐食性の一段の向上が望まれている自動車用鋼板等とし
て好適であり、近年、その需要が高まっている。BACKGROUND OF THE INVENTION Compared to electrogalvanized steel sheets, alloyed hot-dip galvanized steel sheets have the advantage that it is easier to thicken the plating layer and provide excellent corrosion resistance. Therefore,
It is suitable for automotive steel sheets, etc., where further improvement in corrosion resistance is desired, and demand for it has increased in recent years.
【０００３】合金化溶融亜鉛めっき鋼板の表面上には、
その使用される部位によって、電着塗装による塗膜が形
成される。合金化溶融亜鉛めっき鋼板の表面上に対する
塗膜の形成は、一般に、合金化溶融亜鉛めっき層の表面
上に、化成処理によって燐酸塩被膜を形成し、次いで、
カチオンタイプの電着塗装法により、燐酸塩被膜の上に
所定の厚さの塗膜を形成することにより行われる。[0003] On the surface of the alloyed hot-dip galvanized steel sheet,
A coating film is formed by electrodeposition depending on the part where it is used. Formation of a coating film on the surface of an alloyed hot-dip galvanized steel sheet generally involves forming a phosphate film on the surface of the alloyed hot-dip galvanized layer by chemical conversion treatment, and then
This is done by forming a coating film of a predetermined thickness on the phosphate coating using a cationic electrodeposition coating method.
【０００４】しかしながら、上記により形成された塗膜
面には、電着塗装時に発生し、塗膜内に閉じ込められた
水素ガスによってピンホールが生ずる。塗膜に生じたピ
ンホールは、局部的な発錆の起点となるとともに、塗装
面の外観上の欠陥になる。However, pinholes are formed on the surface of the coating film formed as described above due to hydrogen gas generated during electrodeposition coating and trapped within the coating film. Pinholes that occur in the paint film become a starting point for localized rust, and also cause defects in the appearance of the painted surface.
【０００５】上述した問題を解決するめっき鋼板として
、特公昭５８−１５５５４ 号公報には、下記からなる
、カチオン電着塗装用めっき鋼板が開示されている。鋼
板の少なくとも１つの表面上に形成された、４０ｗｔ．
％超の亜鉛を含有する下層としての鉄−亜鉛合金めっき
層、および、前記下層としての鉄−亜鉛合金めっき層の
上に形成された、４０ｗｔ．％以下の亜鉛を含有する上
層としての鉄−亜鉛合金めっき層（以下、先行技術とい
う）。[0005] As a plated steel sheet that solves the above-mentioned problems, Japanese Patent Publication No. 15554/1983 discloses a plated steel sheet for cationic electrodeposition coating, which consists of the following: 40wt. formed on at least one surface of the steel plate.
% of zinc as a lower layer, and an iron-zinc alloy plating layer as a lower layer containing 40wt. Iron-zinc alloy plating layer as an upper layer containing less than % zinc (hereinafter referred to as prior art).
【０００６】[0006]
【発明が解決しようとする課題】上述した先行技術には
、次に述べるような問題がある。即ち、先行技術による
、下層としての厚い合金化溶融鉄−亜鉛合金めっき層と
、上層としての鉄−亜鉛合金電気めっき層とからなるめ
っき鋼板によれば、塗膜に生ずるピンホールは防止され
るが、一方、先行技術によるめっき鋼板に対して、プレ
スなどによって厳しい成形加工を施すと、下層としての
厚い合金化溶融鉄−亜鉛合金めっき層が破壊して、めっ
き層の剥離や脱落が発生する。[Problems to be Solved by the Invention] The above-mentioned prior art has the following problems. That is, according to the prior art coated steel sheet comprising a thick alloyed hot-dip iron-zinc alloy plating layer as a lower layer and an iron-zinc alloy electroplating layer as an upper layer, pinholes occurring in the coating film are prevented. However, on the other hand, when a plated steel sheet made using the prior art is subjected to severe forming processing using a press, etc., the thick alloyed molten iron-zinc alloy plating layer as the lower layer is destroyed, causing peeling or falling off of the plating layer. .
【０００７】めっき層に剥離や脱落が発生すると、燐酸
塩被膜の形成のための化成処理時に、露出した鋼板によ
ってめっき層の溶解が促進される結果、燐酸塩結晶が異
常に成長する。このように異常に成長した燐酸塩結晶は
、結晶水を多量に含有しており、この結晶水が、電着塗
装の塗膜焼き付け時に、燐酸塩結晶から離脱しそして蒸
発する。この結果、塗膜に気泡状欠陥が発生する。この
ような塗膜に発生した気泡状欠陥は、塗装面の外観上の
欠陥になる。[0007] When the plating layer peels off or falls off, the exposed steel sheet accelerates dissolution of the plating layer during chemical conversion treatment to form a phosphate coating, resulting in abnormal growth of phosphate crystals. Phosphate crystals that have grown abnormally in this way contain a large amount of crystal water, and this crystal water separates from the phosphate crystals and evaporates during baking of the electrodeposition coating. As a result, bubble-like defects occur in the coating film. Such bubble-like defects that occur in the paint film become defects in the appearance of the painted surface.
【０００８】従って、この発明の目的は、プレス等によ
って厳しい成形加工が施されても、塗膜に、下層として
の合金化溶融鉄−亜鉛合金めっき層に発生した剥離や脱
落に基づく気泡状欠陥が生ぜず、且つ、ピンホールも殆
ど生じない、電着塗装性に優れた、複数の鉄−亜鉛合金
めっき層を有する鉄−亜鉛合金めっき鋼板を製造するた
めの方法を提供することにある。Therefore, it is an object of the present invention to prevent bubble-like defects caused by peeling or falling off of the alloyed hot-dip iron-zinc alloy plating layer as the lower layer in the coating film, even if severe forming processing is performed using a press or the like. It is an object of the present invention to provide a method for producing an iron-zinc alloy plated steel sheet having a plurality of iron-zinc alloy plating layers, which has excellent electrodeposition coating properties, and which hardly causes pinholes.
【０００９】[0009]
【課題を解決するための手段】本発明者等は、上述した
問題を解決すべく、下層としての合金化溶融鉄−亜鉛合
金めっき層と、上層としての鉄−亜鉛合金電気めっき層
とからなる、複数の鉄−亜鉛合金めっき層を有する鉄−
亜鉛合金めっき鋼板の成形加工時に、下層としての合金
化溶融鉄−亜鉛合金めっき層に剥離や脱落が発生する原
因について、調査および研究を行った結果、次のことが
分かった。[Means for Solving the Problems] In order to solve the above-mentioned problems, the present inventors have proposed an alloyed molten iron-zinc alloy plating layer as a lower layer and an iron-zinc alloy electroplating layer as an upper layer. , iron with multiple iron-zinc alloy plating layers
As a result of investigation and research into the causes of peeling and falling off of the lower alloyed hot-dip iron-zinc alloy plating layer during the forming process of zinc alloy-plated steel sheets, the following was found.
【００１０】下層としての合金化溶融鉄−亜鉛合金めっ
き層は、熱的に形成されているので、めっき層中に内部
応力は存在しない。これに対し、上層としての鉄−亜鉛
合金電気めっき層は、金属の析出により形成されている
ので、めっき層中に大きな内部応力が存在している。こ
の結果、上層としての、内部応力が大きい鉄−亜鉛合金
電気めっき層は、下層としての合金化溶融鉄−亜鉛合金
めっき層を強く拘束し、このような拘束は、局部的に集
中する。このために、合金化溶融鉄−亜鉛合金めっき層
は、極めて脆くなり、成形加工時にめっき層が破壊して
、鋼板から剥離しやすくなる。この結果、塗膜に前述し
た気泡状欠陥が発生する。[0010] Since the alloyed hot-dip iron-zinc alloy plating layer as the lower layer is formed thermally, no internal stress exists in the plating layer. On the other hand, since the iron-zinc alloy electroplated layer as the upper layer is formed by metal precipitation, a large internal stress exists in the plating layer. As a result, the upper layer of iron-zinc alloy electroplating layer with large internal stress strongly restrains the alloyed hot-dip iron-zinc alloy plating layer as the lower layer, and such restraint is locally concentrated. For this reason, the alloyed hot-dip iron-zinc alloy plating layer becomes extremely brittle, and the plating layer is easily destroyed during forming and peeled off from the steel sheet. As a result, the above-mentioned bubble-like defects occur in the coating film.
【００１１】このような、気泡状欠陥の発生と、めっき
層の破壊の程度との関連について調べた結果、気泡状欠
陥が発生していない場合の、下層としての合金化溶融鉄
−亜鉛合金めっき層には、剥離や脱落は生ぜず、微細な
クラックが全面にわたって均一に発生していることが分
かった。上述したことから、プレス成形時に、下層とし
ての合金化溶融鉄−亜鉛合金めっき層に多数の微細なク
ラックを形成させれば、前述した、上層からの局部的な
応力の集中を緩和して、下層としての合金化溶融鉄−亜
鉛合金めっき層の剥離や脱落が防止され、従って、塗膜
に気泡状欠陥が発生しなくなる。[0011] As a result of investigating the relationship between the occurrence of cell defects and the degree of destruction of the plating layer, it was found that the alloyed hot-dip iron-zinc alloy plating as the lower layer when no cell defects occur. It was found that there was no peeling or falling off of the layer, and that fine cracks were uniformly generated over the entire surface. From the above, if many fine cracks are formed in the alloyed hot-dip iron-zinc alloy plating layer as the lower layer during press forming, the aforementioned local stress concentration from the upper layer can be alleviated. Peeling and falling off of the alloyed hot-dip iron-zinc alloy plating layer as the lower layer is prevented, and therefore no bubble-like defects occur in the coating film.
【００１２】この発明は、上記知見に基づいてなされた
ものであって、鋼板を、０．２０ｗｔ．％以下のアルミ
ニウムを含有し、残部が亜鉛および不可避不純物からな
る溶融亜鉛めっき浴に通し、前記鋼板の表面上に亜鉛め
っき層を形成し、次いで、前記鋼板を加熱して、前記亜
鉛めっき層と前記鋼板とを合金化させ、このような合金
化の過程において、前記鋼板が前記溶融亜鉛めっき浴中
に浸入してから、少なくとも、亜鉛めっき層の表面に鉄
−亜鉛合金相が形成されるまでの間、前記鋼板を５００
℃以下の温度に保つことによって、めっき層の表層に
、微細な凹凸を有する柱状鉄−亜鉛合金結晶を生成せし
め、かくして、前記鋼板の少なくとも１つの表面上に、
微細な凹凸を有する柱状鉄−亜鉛合金結晶が生成された
、８〜１２ｗｔ．％の鉄を含有する下層としての合金化
溶融鉄−亜鉛合金めっき層を形成し、次いで、前記下層
としての合金化溶融鉄−亜鉛合金めっき層が形成された
鋼板に対し、弱酸化処理を施すことによって、前記合金
化溶融鉄−亜鉛合金めっき層の表面上に酸化被膜を形成
し、次いで、前記酸化被膜を有する下層としての合金化
溶融鉄−亜鉛合金めっき層が形成された鋼板を、鉄−亜
鉛合金電気めっき浴に通し、前記鋼板に陰極電解処理を
施すことにより、前記下層としての合金化溶融鉄−亜鉛
合金めっき層の上に、５０ｗｔ．％以上の鉄を含有する
、１〜１０ｇ／ｍ２の量の上層としての鉄−亜鉛合金電
気めっき層を形成することに特徴を有するものである。[0012] The present invention was made based on the above-mentioned knowledge, and the present invention is based on the above-mentioned knowledge. % or less of aluminum, with the remainder consisting of zinc and unavoidable impurities, to form a galvanized layer on the surface of the steel sheet, and then heat the steel sheet to form a galvanized layer on the surface of the steel sheet. Alloying the steel plate with the steel plate, and in the alloying process, from the time the steel plate enters the hot-dip galvanizing bath until at least an iron-zinc alloy phase is formed on the surface of the galvanized layer. During this period, the steel plate was
By maintaining the temperature at a temperature below °C, columnar iron-zinc alloy crystals having fine irregularities are formed on the surface layer of the plating layer, and thus, on at least one surface of the steel plate,
Columnar iron-zinc alloy crystals with fine irregularities were produced, 8 to 12 wt. An alloyed molten iron-zinc alloy plating layer is formed as a lower layer containing % of iron, and then a weak oxidation treatment is performed on the steel sheet on which the alloyed molten iron-zinc alloy plating layer is formed as the lower layer. By this, an oxide film is formed on the surface of the alloyed molten iron-zinc alloy plating layer, and then the steel sheet on which the alloyed molten iron-zinc alloy plating layer as a lower layer having the oxide film is formed is coated with iron. - passing through a zinc alloy electroplating bath and subjecting the steel sheet to cathodic electrolytic treatment to deposit 50 wt. It is characterized by forming an iron-zinc alloy electroplated layer as an upper layer in an amount of 1 to 10 g/m2 containing 1 to 10 g/m2 of iron.
【００１３】[0013]
【作用】この発明においては、上述したように、下層と
しての、微細な凹凸を有する合金化溶融鉄−亜鉛合金め
っき層の表面上に酸化被膜が形成されている。この結果
、成形加工時に、酸化被膜を起点として、多数の微細な
クラックが生成するため、この多数の微細なクラックに
よって、上層からの局部応力が下層に集中することが抑
制される。従って、下層としての合金化溶融鉄−亜鉛合
金めっき層に剥離や脱落が生じないので、塗膜に生ずる
気泡状欠陥が防止される。[Function] As described above, in this invention, an oxide film is formed on the surface of the alloyed molten iron-zinc alloy plating layer having fine irregularities as the lower layer. As a result, during molding, many fine cracks are generated starting from the oxide film, and these many fine cracks prevent local stress from the upper layer from concentrating on the lower layer. Therefore, since the alloyed hot-dip iron-zinc alloy plating layer as the lower layer does not peel or fall off, bubble-like defects occurring in the coating film are prevented.
【００１４】以下に、この発明の方法を説明する。鋼板
を、０．２０ｗｔ．％以下のアルミニウムを含有し、残
部が亜鉛および不可避不純物からなる溶融亜鉛めっき浴
に通し、鋼板の表面上に亜鉛めっき層を形成する。この
ようにして、その表面上に、亜鉛めっき層が形成された
鋼板を加熱して、亜鉛めっき層と鋼板とを合金化させる
。この合金化の過程において、鋼板が溶融亜鉛めっき浴
中に浸入してから、少なくとも、亜鉛めっき層の表面に
鉄−亜鉛合金相が形成されるまでの間、即ち、合金化の
所期段階において、鋼板を５００ ℃以下の温度に保つ
。この結果、めっき層の表層に、微細な凹凸を有する柱
状の鉄−亜鉛合金結晶が生成する。このような柱状の鉄
−亜鉛合金結晶がめっき層中に存在することにより、耐
パウダリング性が向上する。The method of the present invention will be explained below. A steel plate of 0.20wt. The steel sheet is passed through a hot-dip galvanizing bath containing up to 30% aluminum, with the balance consisting of zinc and unavoidable impurities, to form a galvanized layer on the surface of the steel sheet. In this way, the steel plate with the galvanized layer formed on its surface is heated to alloy the galvanized layer and the steel plate. In this alloying process, after the steel sheet enters the hot-dip galvanizing bath, at least until the iron-zinc alloy phase is formed on the surface of the galvanized layer, that is, at the initial stage of alloying. , keep the steel plate at a temperature below 500°C. As a result, columnar iron-zinc alloy crystals having fine irregularities are formed on the surface layer of the plating layer. The presence of such columnar iron-zinc alloy crystals in the plating layer improves powdering resistance.
【００１５】鋼板を５００ ℃以下の温度に保つ手段と
しては、例えば、合金化のための加熱の少なくとも初期
段階において、加熱炉の温度を、鋼板が５００ ℃以下
の温度に保たれるように制御することによって行うこと
ができる。このような加熱炉として、高周波誘導加熱炉
を使用すれば、加熱温度の制御を容易に行うことができ
る。[0015] As a means for keeping the steel plate at a temperature of 500°C or less, for example, at least in the initial stage of heating for alloying, the temperature of the heating furnace is controlled so that the steel plate is kept at a temperature of 500°C or less. This can be done by If a high frequency induction heating furnace is used as such a heating furnace, the heating temperature can be easily controlled.
【００１６】上述のようにして、下層としての合金化溶
融鉄−亜鉛合金めっき層の表層に、微細な凹凸を有する
柱状の鉄−亜鉛合金結晶が生成した鋼板に対し、弱酸化
処理を施す。この結果、柱状の鉄−亜鉛合金結晶の凸部
の表面に、硬い酸化被膜が生成する。鋼板に対し弱酸化
処理を施す手段としては、鋼板を、大気中または露点の
高い雰囲気中において加熱するか、または、鋼板を、薬
液、例えば、硝酸および過酸化水素を含有する水溶液中
に浸漬することによって行うことができる。As described above, a steel plate in which columnar iron-zinc alloy crystals having fine irregularities are formed on the surface layer of the alloyed hot-dip iron-zinc alloy plating layer as the lower layer is subjected to a weak oxidation treatment. As a result, a hard oxide film is formed on the surface of the convex portion of the columnar iron-zinc alloy crystal. As a means of subjecting a steel plate to mild oxidation treatment, the steel plate is heated in the air or in an atmosphere with a high dew point, or the steel plate is immersed in a chemical solution, for example, an aqueous solution containing nitric acid and hydrogen peroxide. This can be done by:
【００１７】大気中または露点の高い雰囲気中における
、鋼板の加熱温度は、２５０ 〜３５０ ℃の範囲内と
すべきである。加熱温度が２５０ ℃未満では、酸化被
膜を十分に生成させることができない。一方、加熱温度
が３５０ ℃を超えると、亜鉛めっき層の合金化が必要
以上に進行し、合金化溶融鉄−亜鉛合金めっき層中の鉄
含有率が多くなり過ぎる問題が生ずる。[0017] The heating temperature of the steel plate in the air or in an atmosphere with a high dew point should be within the range of 250 to 350°C. If the heating temperature is less than 250° C., an oxide film cannot be sufficiently formed. On the other hand, if the heating temperature exceeds 350° C., alloying of the galvanized layer will proceed more than necessary, causing a problem that the iron content in the alloyed molten iron-zinc alloy plating layer will become too high.
【００１８】鋼板の表面上に亜鉛めっき層を形成するた
めの溶融亜鉛めっき浴としては、０．２０ｗｔ．％以下
のアルミニウムを含有し、残部が亜鉛および不可避不純
物からなるめっき浴を使用すべきである。めっき浴中の
アルミニウム含有量が０．２０ｗｔ．％を超えると、合
金化処理段階における、鉄−亜鉛合金相の生成が著しく
抑制される結果、鋼板の少なくとも１つの表面上に形成
される合金化溶融鉄−亜鉛合金めっき層が不均一になる
問題が生ずる。The hot-dip galvanizing bath for forming a galvanized layer on the surface of the steel sheet is 0.20 wt. % aluminum, with the remainder consisting of zinc and unavoidable impurities. When the aluminum content in the plating bath is 0.20wt. %, the formation of an iron-zinc alloy phase during the alloying process is significantly suppressed, resulting in a non-uniform alloyed hot-dip iron-zinc alloy plating layer formed on at least one surface of the steel sheet. A problem arises.
【００１９】鋼板の少なくとも１つの表面上に形成され
る合金化溶融鉄−亜鉛合金めっき層中の鉄含有量は、８
〜１２ｗｔ．％の範囲内に限定すべきである。鉄含有量
が８ｗｔ．％未満では、成形加工時に、めっき層の鋼板
からの剥離即ちフレーキングが発生する。一方、鉄含有
量が１２ｗｔ．％を超えると、加工性が劣化し、成形加
工時にめっき層の粉状の剥離即ちパウダリングが発生す
る。The iron content in the alloyed hot-dip iron-zinc alloy plating layer formed on at least one surface of the steel sheet is 8
~12wt. It should be limited within the range of %. Iron content is 8wt. If it is less than %, the plating layer will peel off from the steel plate during forming, that is, flaking will occur. On the other hand, the iron content is 12wt. If it exceeds %, workability deteriorates and powder-like peeling of the plating layer occurs during molding, that is, powdering.
【００２０】上層としての鉄−亜鉛合金電気めっき層中
の鉄含有量は、５０ｗｔ．％以上とすべきである。鉄含
有量が５０ｗｔ．％未満では、塗膜に気泡状欠陥および
ピンホールが発生する。The iron content in the iron-zinc alloy electroplated layer as the upper layer is 50 wt. % or more. Iron content is 50wt. If it is less than %, bubble-like defects and pinholes will occur in the coating film.
【００２１】上層としての鉄−亜鉛合金電気めっき層の
めっき量は、鋼板の片面当たり１〜１０ｇ／ｍ２の範囲
内とすべきである。めっき量が鋼板の片面当たり１ｇ／
ｍ２未満では、下層としての合金化溶融鉄−亜鉛合金め
っき層を均一に被覆することができず、塗膜にピンホー
ルが発生する。一方、めっき量が鋼板の片面当たり１０
ｇ／ｍ２を超えると、めっき層が厚くなり過ぎ、加工性
が劣化し、成形加工時にめっき層の粉状の剥離即ちパウ
ダリングが発生する。The coating weight of the iron-zinc alloy electroplated layer as the upper layer should be within the range of 1 to 10 g/m 2 per side of the steel sheet. The amount of plating is 1g per side of the steel plate.
If it is less than m2, the alloyed hot-dip iron-zinc alloy plating layer as the lower layer cannot be uniformly coated, and pinholes will occur in the coating film. On the other hand, the plating amount is 10 per side of the steel plate.
If it exceeds g/m2, the plating layer becomes too thick, the workability deteriorates, and powder-like peeling of the plating layer, that is, powdering, occurs during molding.
【００２２】下層としての合金化溶融鉄−亜鉛合金めっ
き層のめっき量は、鋼板の片面当たり３０〜７０ｇ／ｍ
２の範囲内であることが好ましい。めっき量が鋼板の片
面当たり３０ｇ／ｍ２未満では、耐食性が劣化する。一
方、めっき量が鋼板の片面当たり、７０ｇ／ｍ２を超え
ると、加工性が劣化する。[0022] The plating amount of the alloyed hot-dip iron-zinc alloy plating layer as the lower layer is 30 to 70 g/m per one side of the steel plate.
It is preferably within the range of 2. If the amount of plating is less than 30 g/m2 per side of the steel plate, corrosion resistance will deteriorate. On the other hand, when the amount of plating exceeds 70 g/m2 per side of the steel plate, workability deteriorates.
【００２３】次に、この発明の方法を、実施例により、
比較例と対比しながら説明する。[0023] Next, the method of the present invention will be described by way of example.
This will be explained in comparison with a comparative example.
【実施例】板厚０．８ｍｍ の冷延鋼板に対し、下記に
示す条件で合金化溶融亜鉛めっき処理を施し、鋼板の表
面上に、微細な凹凸を有する柱状鉄−亜鉛合金結晶が生
成された下層としての合金化溶融鉄−亜鉛合金めっき層
を形成した。
■ めっき浴化学成分組成：
Ａｌ： ０．１２ｗｔ．％ 、 Ｚｎ： 残り■
めっき浴温度： ４６０℃
■ めっき浴浸入供試体温度： ４７０℃■ 合金
化温度 ： ４９０℃
■ 合金化時間 ：所定の鉄含有量が得られるよう
に調整。[Example] A cold-rolled steel plate with a thickness of 0.8 mm was subjected to alloying hot-dip galvanizing treatment under the conditions shown below, and columnar iron-zinc alloy crystals with fine irregularities were formed on the surface of the steel plate. An alloyed hot-dip iron-zinc alloy plating layer was formed as a lower layer. ■ Plating bath chemical composition: Al: 0.12wt. %, Zn: Remaining■
Plating bath temperature: 460°C ■ Temperature of specimen immersed in plating bath: 470°C ■ Alloying temperature: 490°C ■ Alloying time: Adjusted to obtain the specified iron content.
【００２４】次いで、下層としての合金化溶融鉄−亜鉛
合金めっき層が形成された鋼板に対し、加熱または薬液
中への浸漬からなる弱酸化処理を施して、めっき層の表
面上に酸化被膜を形成した。Next, the steel sheet on which the alloyed hot-dip iron-zinc alloy plating layer has been formed as the lower layer is subjected to a weak oxidation treatment consisting of heating or immersion in a chemical solution to form an oxide film on the surface of the plating layer. Formed.
【００２５】次いで、酸化被膜を有する下層としての合
金化溶融鉄−亜鉛合金めっき層が形成された鋼板に対し
、下記に示す条件で電気めっき処理を施し、下層として
の合金化溶融鉄−亜鉛合金めっき層の表面上に、所定量
の鉄−亜鉛合金電気めっき層を形成した。
■ めっき浴の化学成分組成：
ＦｅＳＯ４ ・７Ｈ２Ｏ：３８０ｇ／ｌ、
ＺｎＳＯ４ ・７Ｈ２Ｏ ：２０ｇ／ｌ 、
Ｎａ２ＳＯ４ ： ３０ｇ／ｌ、
ＣＨ３ＣＯＯＮａ・３Ｈ２Ｏ：２０ｇ／ｌ■ めっ
き浴のｐＨ値：２．０
■ めっき浴の温度：５０℃
■ めっき電気量 ：５０Ａ／ｄｍ２Next, the steel sheet on which the alloyed molten iron-zinc alloy plating layer as a lower layer having an oxide film was formed was electroplated under the conditions shown below to coat the alloyed molten iron-zinc alloy as the lower layer. A predetermined amount of an iron-zinc alloy electroplating layer was formed on the surface of the plating layer. ■ Chemical composition of plating bath: FeSO4 ・7H2O: 380g/l,
ZnSO4 ・7H2O: 20g/l, Na2SO4: 30g/l,
CH3COONa・3H2O: 20g/l ■ pH value of plating bath: 2.0 ■ Temperature of plating bath: 50℃ ■ Plating electricity amount: 50A/dm2
【００２６】
このようにして、鋼板の表面上に、酸化被膜が生成され
た下層としての合金化溶融鉄−亜鉛合金めっき層と、上
層としての鉄−亜鉛合金電気めっき層とを有する、この
発明の鉄−亜鉛合金めっき鋼板の供試体（以下、本発明
供試体という）Ｎｏ． １〜６を調製した。
第１表に、本発明供試体Ｎｏ． １〜６の弱酸化処理手
段を示す。[0026]
In this way, the steel plate of the present invention has an alloyed hot-dip iron-zinc alloy plating layer as a lower layer on which an oxide film is formed and an iron-zinc alloy electroplating layer as an upper layer on the surface of the steel sheet. Zinc alloy coated steel sheet specimen (hereinafter referred to as the present invention specimen) No. 1 to 6 were prepared. Table 1 shows the present invention specimen No. The weak oxidation treatment means 1 to 6 are shown below.
【００２７】[0027]
【００２８】[0028]
【比較例】比較のために、下層としての合金化溶融鉄−
亜鉛合金めっき層の表層に酸化被膜が形成されていない
ほかは、上述した実施例と同じ条件でめっき層を形成し
た比較用の鉄−亜鉛合金めっき鋼板の供試体（以下、比
較用供試体という）Ｎｏ． １を調製した。[Comparative Example] For comparison, alloyed molten iron as a lower layer -
A comparative iron-zinc alloy coated steel sheet specimen (hereinafter referred to as the comparative specimen) was prepared with a plating layer formed under the same conditions as the above-mentioned example, except that no oxide film was formed on the surface layer of the zinc alloy plating layer. ) No. 1 was prepared.
【００２９】このようにして調製された本発明供試体お
よび比較用供試体の各々について、電着塗装性を、以下
に述べる性能試験によって調査した。電着塗装性試験本
発明供試体および比較用供試体の各々の表面上に、浸漬
処理によって燐酸塩被膜を形成した後、下記条件によっ
てカチオンタイプの電着塗装を施した。
電圧 ： ２８０Ｖ
浴温 ： ２７℃塗膜の厚さ
： ２０μｍ
焼き付け温度： １７５℃
焼き付け時間： ２０分
塗料 ： エレクロンＮｏ． ２００
０ （関西ペイント株式会社製）The electrocoatability of each of the specimens of the present invention and comparative specimens thus prepared was investigated by the performance test described below. Electrodeposition coating property test After a phosphate film was formed on the surface of each of the present invention specimen and comparative specimen by dipping treatment, cationic electrodeposition coating was applied under the following conditions. Voltage: 280V Bath temperature: 27℃ Paint film thickness
: 20μm Baking temperature: 175℃ Baking time: 20 minutes Paint: Elekron No. 200
0 (manufactured by Kansai Paint Co., Ltd.)
【００３０】上記のようにして電着塗装を施した供試体
に対し、直径３０ｍｍの頭部を有する平頭ポンチを使用
して高さ１０ｍｍの張り出し成形加工を施し、供試体の
塗膜に生じた気泡状欠陥の個数を目視によって調べ、下
記によって評価した。
◎：０〜５個、 ○：６〜１０個、 △：１１〜１
００ 個、 ×：１０１ 個[0030] The specimen coated with electrodeposition as described above was subjected to an overhang molding process to a height of 10 mm using a flat head punch with a head diameter of 30 mm. The number of bubble-like defects was visually inspected and evaluated as follows. ◎: 0 to 5 pieces, ○: 6 to 10 pieces, △: 11 to 1
00 pieces, ×: 101 pieces
【００３１】第２表に、本発明供試体および比較用供試
体の各々に対する、上述した電着塗装性試験結果を、め
っき層の成分組成およびめっき量と共に示す。[0031] Table 2 shows the results of the above-mentioned electrodeposition coating property test for each of the specimens of the present invention and comparative specimens, together with the component composition of the plating layer and the amount of plating.
【００３２】[0032]
【００３３】第１表および第２表から明らかなように、
下層としての合金化溶融鉄−亜鉛合金めっき層に酸化被
膜が形成されていない比較用供試体Ｎｏ． １は、塗膜
中に気泡状欠陥が極めて多量に発生し、電着塗装性が悪
かった。これに対して、本発明供試体Ｎｏ． １〜６は
、何れも、塗膜に殆ど気泡状欠陥が発生せず、電着塗装
性に優れていた。As is clear from Tables 1 and 2,
Comparative specimen No. 1 in which no oxide film was formed on the alloyed hot-dip iron-zinc alloy plating layer as the lower layer. In No. 1, an extremely large number of bubble-like defects were generated in the coating film, and the electrodeposition coating properties were poor. In contrast, the present invention specimen No. No. 1 to No. 6 had almost no bubble-like defects in the coating film and had excellent electrodeposition coating properties.
【００３４】[0034]
【発明の効果】以上述べたように、この発明によれば、
プレス等によって厳しい成形加工が施されても、塗膜に
、下層としての合金化溶融鉄−亜鉛合金めっき層に発生
した剥離や脱落に基づく気泡状欠陥が生ぜず、且つ、ピ
ンホールも殆ど生じない、電着塗装性に優れた、複数の
鉄−亜鉛合金めっき層を有する鉄−亜鉛合金めっき鋼板
が得られる、工業上有用な効果がもたらされる。[Effects of the Invention] As described above, according to the present invention,
Even when subjected to severe forming processing using presses, etc., the paint film does not have bubble-like defects due to peeling or falling off of the underlying alloyed hot-dip iron-zinc alloy plating layer, and almost no pinholes occur. This brings about an industrially useful effect in that an iron-zinc alloy plated steel sheet having a plurality of iron-zinc alloy plating layers with excellent electrodeposition coating properties can be obtained.
Claims (3)
ミニウムを含有し、残部が亜鉛および不可避不純物から
なる溶融亜鉛めっき浴に通し、前記鋼板の表面上に亜鉛
めっき層を形成し、次いで、前記鋼板を加熱して、前記
亜鉛めっき層と前記鋼板とを合金化させ、このような合
金化の過程において、前記鋼板が前記溶融亜鉛めっき浴
中に浸入してから、少なくとも、亜鉛めっき層の表面に
鉄−亜鉛合金相が形成されるまでの間、前記鋼板を５０
０ ℃以下の温度に保つことによって、めっき層の表層
に、微細な凹凸を有する柱状鉄−亜鉛合金結晶を生成せ
しめ、かくして、前記鋼板の少なくとも１つの表面上に
、微細な凹凸を有する柱状鉄−亜鉛合金結晶が生成され
た、８〜１２ｗｔ．％の鉄を含有する下層としての合金
化溶融鉄−亜鉛合金めっき層を形成し、次いで、前記下
層としての合金化溶融鉄−亜鉛合金めっき層が形成され
た鋼板に対し、弱酸化処理を施すことによって、前記合
金化溶融鉄−亜鉛合金めっき層の表面上に酸化被膜を形
成し、次いで、前記酸化被膜を有する下層としての合金
化溶融鉄−亜鉛合金めっき層が形成された鋼板を、鉄−
亜鉛合金電気めっき浴に通し、前記鋼板に陰極電解処理
を施すことにより、前記下層としての合金化溶融鉄−亜
鉛合金めっき層の上に、５０ｗｔ．％以上の鉄を含有す
る、１〜１０ｇ／ｍ２の量の上層としての鉄−亜鉛合金
電気めっき層を形成することを特徴とする、電着塗装性
に優れた、複数の鉄−亜鉛合金めっき層を有する鉄−亜
鉛合金めっき鋼板の製造方法。Claim 1: A steel plate having a weight of 0.20wt. % or less of aluminum, with the remainder consisting of zinc and unavoidable impurities, to form a galvanized layer on the surface of the steel sheet, and then heat the steel sheet to form a galvanized layer on the surface of the steel sheet. Alloying the steel plate with the steel plate, and in the alloying process, from the time the steel plate enters the hot-dip galvanizing bath until at least an iron-zinc alloy phase is formed on the surface of the galvanized layer. The steel plate was heated for 50 minutes.
By maintaining the temperature at 0° C. or lower, columnar iron-zinc alloy crystals having fine irregularities are generated on the surface layer of the plating layer, and thus columnar iron having fine irregularities is formed on at least one surface of the steel sheet. - Zinc alloy crystals were produced, 8-12 wt. An alloyed molten iron-zinc alloy plating layer is formed as a lower layer containing % of iron, and then a weak oxidation treatment is performed on the steel sheet on which the alloyed molten iron-zinc alloy plating layer is formed as the lower layer. By this, an oxide film is formed on the surface of the alloyed molten iron-zinc alloy plating layer, and then the steel sheet on which the alloyed molten iron-zinc alloy plating layer as a lower layer having the oxide film is formed is coated with iron. −
By passing the steel sheet through a zinc alloy electroplating bath and subjecting it to cathodic electrolytic treatment, 50 wt. A plurality of iron-zinc alloy platings with excellent electrodeposition coating properties, characterized by forming an iron-zinc alloy electroplating layer as an upper layer in an amount of 1 to 10 g/m2 containing 1 to 10 g/m2 of iron. A method for manufacturing an iron-zinc alloy coated steel sheet having a layer.
としての合金化溶融鉄−亜鉛合金めっき層が形成された
鋼板に対する前記弱酸化処理を、大気中または露点の高
い雰囲気中において、２５０ 〜３５０ ℃の範囲内の
温度で３０秒以上加熱することによって行う、請求項１
記載の方法。2. The weak oxidation treatment of the steel sheet having an alloyed hot-dip iron-zinc alloy plating layer as a lower layer on at least one surface thereof is carried out in the air or in an atmosphere with a high dew point at a temperature of 250 to 350°C. Claim 1: The method is carried out by heating at a temperature within the range of 30 seconds or more.
Method described.
としての合金化溶融鉄−亜鉛合金めっき層が形成された
鋼板に対する前記弱酸化処理を、薬液中に浸漬すること
によって行う、請求項１記載の方法。3. The weak oxidation treatment of the steel sheet having an alloyed hot-dip iron-zinc alloy plating layer as a lower layer formed on at least one surface thereof is performed by immersing the steel sheet in a chemical solution. the method of.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3014803A JP2541380B2 (en) | 1991-01-14 | 1991-01-14 | Method for producing iron-zinc alloy-plated steel sheet having a plurality of iron-zinc alloy plating layers having excellent electrodeposition coatability |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3014803A JP2541380B2 (en) | 1991-01-14 | 1991-01-14 | Method for producing iron-zinc alloy-plated steel sheet having a plurality of iron-zinc alloy plating layers having excellent electrodeposition coatability |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04236752A true JPH04236752A (en) | 1992-08-25 |
| JP2541380B2 JP2541380B2 (en) | 1996-10-09 |
Family
ID=11871202
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3014803A Expired - Lifetime JP2541380B2 (en) | 1991-01-14 | 1991-01-14 | Method for producing iron-zinc alloy-plated steel sheet having a plurality of iron-zinc alloy plating layers having excellent electrodeposition coatability |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2541380B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT412403B (en) * | 2003-07-29 | 2005-02-25 | Voestalpine Stahl Gmbh | Corrosion-protection layer for hardened metallic profiled structural part of motor vehicle, has roller-formed profiled elements having affinity to oxygen, and oxide skin comprising oxides of elements |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63157847A (en) * | 1986-12-19 | 1988-06-30 | Nippon Steel Corp | Manufacture of alloying-galvanized steel sheet |
| JPH01108396A (en) * | 1987-10-21 | 1989-04-25 | Sumitomo Metal Ind Ltd | Production of galvannealed steel sheet for coating by cationic electrodeposition |
| JPH0257670A (en) * | 1988-08-22 | 1990-02-27 | Nippon Steel Corp | Alloying hot dip galvanized steel sheet excellent in powdering resistance and flaking resistance and its production |
| JPH02243780A (en) * | 1989-03-16 | 1990-09-27 | Kawasaki Steel Corp | Production of alloyed hot dip galvanized steel sheet having resistance to powdering property |
-
1991
- 1991-01-14 JP JP3014803A patent/JP2541380B2/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63157847A (en) * | 1986-12-19 | 1988-06-30 | Nippon Steel Corp | Manufacture of alloying-galvanized steel sheet |
| JPH01108396A (en) * | 1987-10-21 | 1989-04-25 | Sumitomo Metal Ind Ltd | Production of galvannealed steel sheet for coating by cationic electrodeposition |
| JPH0257670A (en) * | 1988-08-22 | 1990-02-27 | Nippon Steel Corp | Alloying hot dip galvanized steel sheet excellent in powdering resistance and flaking resistance and its production |
| JPH02243780A (en) * | 1989-03-16 | 1990-09-27 | Kawasaki Steel Corp | Production of alloyed hot dip galvanized steel sheet having resistance to powdering property |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT412403B (en) * | 2003-07-29 | 2005-02-25 | Voestalpine Stahl Gmbh | Corrosion-protection layer for hardened metallic profiled structural part of motor vehicle, has roller-formed profiled elements having affinity to oxygen, and oxide skin comprising oxides of elements |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2541380B2 (en) | 1996-10-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3045612B2 (en) | High corrosion resistant nickel-plated steel strip and its manufacturing method | |
| MXPA04006178A (en) | Surface treated steel plate and method for production thereof. | |
| US4036600A (en) | Steel substrate electroplated with Al powder dispersed in Zn | |
| JPH0753901B2 (en) | Hot dip galvanizing method | |
| JP2619550B2 (en) | Manufacturing method of galvannealed steel sheet | |
| JP7247946B2 (en) | Hot-dip galvanized steel sheet and its manufacturing method | |
| CN114846171B (en) | Hot dip plated alloy steel material having excellent corrosion resistance and method for producing same | |
| JP2936718B2 (en) | Method for producing iron-based alloy plated steel sheet having a plurality of iron-based alloy plating layers excellent in electrodeposition coating property and workability | |
| JPH04236752A (en) | Production of iron-zinc alloy plated steel sheet having plural iron-zinc alloy plating layers having excellent electrodeposition coating suitability | |
| JPH11140587A (en) | Galvannealed steel sheet excellent in plating adhesion | |
| JP3637702B2 (en) | Method for producing hot-dip galvanized steel sheet with excellent workability | |
| CN114901853A (en) | Zn-Al-Mg series hot dip alloyed steel material excellent in corrosion resistance of worked portion and method for producing same | |
| KR20210145195A (en) | Method for manufacturing steel strip with improved bonding in hot dip plating | |
| JP3581451B2 (en) | Manufacturing method of zinc-tin alloy plated steel sheet | |
| JPH04236753A (en) | Production of iron-zinc alloy plated steel sheet having plural iron-zinc alloy plating layers having excellent electrodeposition coating suitability | |
| KR102602054B1 (en) | Method for manufacturing steel strip with improved bonding of hot dip galvanizing | |
| JPS62256959A (en) | Manufacture of alloying-plated steel sheet | |
| JPH0319297B2 (en) | ||
| JP2936717B2 (en) | Method for producing iron-based alloy plated steel sheet having a plurality of iron-based alloy plating layers excellent in electrodeposition coating property and workability | |
| JP3102785B1 (en) | Electrogalvanized steel sheet and method for producing the same | |
| JPH05171392A (en) | Method for galvanizing high-strength steel sheet | |
| JPH05156416A (en) | Galvanizing method for si-containing steel sheet | |
| JPH04202784A (en) | Production of iron-zinc alloy plated steel sheet excellent in electrodeposition coating property and workability and having plural iron-zinc alloy plating layers | |
| JPH07243012A (en) | Production of galvannealed steel sheet excellent in external appearance of surface | |
| JPH04276055A (en) | Manufacture of differential galvannealed steel |