JP2697485B2 - Manufacturing method of high corrosion resistant galvannealed steel sheet - Google Patents
Manufacturing method of high corrosion resistant galvannealed steel sheetInfo
- Publication number
- JP2697485B2 JP2697485B2 JP4135075A JP13507592A JP2697485B2 JP 2697485 B2 JP2697485 B2 JP 2697485B2 JP 4135075 A JP4135075 A JP 4135075A JP 13507592 A JP13507592 A JP 13507592A JP 2697485 B2 JP2697485 B2 JP 2697485B2
- Authority
- JP
- Japan
- Prior art keywords
- steel sheet
- corrosion resistance
- treatment
- dip galvanized
- galvanized steel
- 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.)
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- Other Surface Treatments For Metallic Materials (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、高耐食性合金化溶融亜
鉛めっき鋼板の製造法に関し、さらに詳述すれば、特に
優れた塗装後の耐食性を有する合金化溶融亜鉛めっき鋼
板を安定的に製造する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 a galvannealed steel sheet having high corrosion resistance and, more particularly, to a method for stably producing a galvannealed steel sheet having particularly excellent corrosion resistance after painting. How to do it.
【０００２】[0002]
【従来の技術】溶融亜鉛めっき鋼板の塗装後耐食性を向
上させる技術として、古くから、Co、Ni置換めっきが知
られている。また、その方法を亜鉛−アルミニウム合金
めっき鋼板に適用した例として、特開昭62−20880 号公
報開示の方法がある。それは、表面に濃化したAl2O3 相
をpH＝11以上のアルカリ性水溶液で処理して溶解除去す
る方法である。2. Description of the Related Art As a technique for improving the corrosion resistance of a hot-dip galvanized steel sheet after painting, Co and Ni substitution plating has long been known. Further, as an example of applying the method to a zinc-aluminum alloy plated steel sheet, there is a method disclosed in Japanese Patent Application Laid-Open No. 62-20880. This is a method in which the Al 2 O 3 phase concentrated on the surface is treated with an alkaline aqueous solution having a pH of 11 or more to be dissolved and removed.
【０００３】また、亜鉛の耐食性塗装下地生成法とし
て、特開昭49−16635 号公報開示の方法があり、これは
６価のクロムを含む強アルカリ性溶液に浸漬し、次い
で、６価のクロムを含む酸性溶液に浸漬することを特徴
とする塗装下地生成法である。いずれも、めっき後の表
面酸化物を除去するという点で、めっき表面が均一化さ
れ、塗装後の耐食性の向上が期待できる。Further, as a method for producing a corrosion-resistant undercoat of zinc, there is a method disclosed in JP-A-49-16635, which is immersed in a strongly alkaline solution containing hexavalent chromium and then immersed in hexavalent chromium. This is a method for producing a paint base, characterized by immersing the base material in an acidic solution containing the base material. In any case, in terms of removing the surface oxide after plating, the plating surface is made uniform, and improvement in corrosion resistance after painting can be expected.
【０００４】一方、合金化溶融亜鉛めっき鋼板は、高温
処理による合金化過程において、その表層にAl2O3 やP
b、Sbその他の不純物および亜鉛酸化物が濃化してきて
おり、かつ、めっき層表面は不平滑で多孔質な形状をな
している。また、合金化はめっき層−地鉄界面での反応
であるため合金化初期に生成するFe％の低いζ相（FeZn
13) がめっき表面に残存しやすく、めっき層の表層部
は、Al2O3 等の酸化物、ζ相、さらにはδ相 (FeZn7)が
入り交じった状態にある。しかも、実際には鋼帯の機械
特性値の調整のため調質圧延されることから、調質圧延
後はロールの凹凸により、めっき層の内側部が掘り起こ
されており、極めて、局部電池を形成し易い状態となっ
ている。[0004] On the other hand, during the alloying process by high temperature treatment, the alloyed hot-dip galvanized steel sheet has Al 2 O 3 or P
b, Sb and other impurities and zinc oxide are becoming concentrated, and the surface of the plating layer is uneven and porous. In addition, since alloying is a reaction at the interface between the plating layer and the ferrous iron, a low ％ phase (FeZn
13 ) tends to remain on the plating surface, and the surface layer of the plating layer is in a state in which an oxide such as Al 2 O 3 , a ζ phase, and further a δ phase (FeZn 7 ) are mixed. In addition, since the steel strip is actually temper rolled to adjust the mechanical properties, the inner surface of the plating layer is dug up due to the unevenness of the roll after temper rolling, and extremely forms a local battery. It is in a state where it is easy to do.
【０００５】このような合金化溶融亜鉛めっき鋼板の塗
装後耐食性をさらに高めるためには、実際の処理ライン
において従来の短時間のアルカリ処理だけでは充分とは
言えないのが現状である。[0005] In order to further enhance the corrosion resistance of such galvannealed steel sheet after coating, conventional alkali treatment in a short time in an actual processing line is not sufficient at present.
【０００６】また、合金化溶融亜鉛めっき鋼板の化成処
理方法として、アルミニウムフッ素化合物を含むクロム
酸処理法 (特開昭55−44537 号公報参照) が開示されて
いるが、上記のように複雑な構造のめっき層を有する合
金化溶融亜鉛めっき鋼板の塗装後耐食性のさらなる改善
をフッ素化合物のエッチング作用だけで行うのは困難で
ある。As a chemical conversion treatment method for an alloyed hot-dip galvanized steel sheet, a chromic acid treatment method containing an aluminum fluorine compound (see Japanese Patent Application Laid-Open No. 55-44537) has been disclosed. It is difficult to further improve the post-painting corrosion resistance of an alloyed hot-dip galvanized steel sheet having a plated layer having a structure only by the etching action of a fluorine compound.
【０００７】[0007]
【発明が解決しようとする課題】このように、今日、合
金化溶融亜鉛めっき鋼板は、塗装後の耐食性に優れるた
め、自動車、家電分野で広く使用されているが、合金化
溶融亜鉛めっき鋼板の合金化度 (相構造) によって、そ
の塗装後の耐食性、とりわけ塗膜フクレに関してはその
バラツキは大きい。ここに、本発明の目的は、安定した
塗装後耐食性を発揮できる合金化溶融亜鉛めっき鋼板の
製造法を提供することである。As described above, alloyed hot-dip galvanized steel sheets are widely used today in the fields of automobiles and home appliances because of their excellent corrosion resistance after painting. Depending on the degree of alloying (phase structure), the variation in corrosion resistance after coating, especially with respect to coating blisters, is large. Here, an object of the present invention is to provide a method for producing an alloyed hot-dip galvanized steel sheet that can exhibit stable corrosion resistance after painting.
【０００８】[0008]
【課題を解決するための手段】本発明者らは、未塗装で
の耐食性を確保し、しかも従来の合金化溶融亜鉛めっき
鋼板のもつ塗装後耐食性を安定的に発揮させるため、鋭
意検討した結果、調質圧延時のロールの凹凸および加工
度を限定することにより合金化めっき層の内側部と表面
部との不均一性を抑制するとともに、さらに、pHの高い
アルカリ性溶液で合金化めっき層の表面部に形成された
酸化物層を一部または全部溶解し、同時に、このアルカ
リ性溶液中にNi、Coもしくはその両者を添加し、Niおよ
び／またはCoを置換析出させてめっき層の表面電位を貴
にすることにより、極めて優れた塗装後の耐食性を有す
る合金化溶融亜鉛めっき鋼板が安定的に製造可能なこと
を見い出し、本発明に至った。Means for Solving the Problems The inventors of the present invention have conducted intensive studies to ensure the corrosion resistance in the unpainted state and to stably exhibit the post-painting corrosion resistance of the conventional galvannealed steel sheet. In addition to suppressing the unevenness of the inside and the surface of the alloyed plating layer by limiting the unevenness of the roll and the degree of processing at the time of temper rolling, the alloyed plating layer is further treated with a high pH alkaline solution. Part or all of the oxide layer formed on the surface is dissolved, and at the same time, Ni or Co or both are added to the alkaline solution to displace and deposit Ni and / or Co to lower the surface potential of the plating layer. By making it noble, it has been found that an alloyed hot-dip galvanized steel sheet having extremely excellent corrosion resistance after painting can be stably manufactured, and the present invention has been accomplished.
【０００９】また、塗装後耐食性をさらに高めるため
に、合金化溶融亜鉛めっき鋼板の表層をδ1 相単相にす
るため、合金化めっき皮膜中のFe％を10wt％以上にする
と良いことが分かった。Further, in order to further increase the corrosion resistance after coating, it is found that the Fe% in the alloyed galvanized film should be 10 wt% or more in order to make the surface layer of the galvannealed steel sheet a single phase of δ 1 phase. Was.
【００１０】以上より、本発明の要旨とするところは: (1) 合金化溶融亜鉛めっき鋼板の製造法であって、溶融
亜鉛めっき鋼板の合金化処理後、表面粗さRa＝2.5 μm
以下のロールを用いて伸び率 0.8％以下の調質圧延を行
い、次いでNiおよびCoの一種または二種を合計で0.01重
量％以上0.5 重量％以下含有するpH＝12以上のアルカリ
性水溶液で処理することを特徴とする、塗装後耐食性に
優れた合金化溶融亜鉛めっき鋼板の製造法、および (2) 合金化処理後のめっき皮膜中のFe％を10重量％以上
とするとともに、前記アルカリ性水溶液による処理後、
クロメート処理する、上記(1) 記載の塗装後耐食性に優
れた合金化溶融亜鉛めっき鋼板の製造法である。From the above, the gist of the present invention is as follows: (1) A method for producing an alloyed hot-dip galvanized steel sheet, wherein after galvannealing the hot-dip galvanized steel sheet, the surface roughness is Ra = 2.5 μm
Perform temper rolling with an elongation of 0.8% or less using the following rolls, and then treat with an alkaline aqueous solution containing at least 0.01% by weight and at most 0.5% by weight of Ni and Co and having a pH of 12 or more in total. A method for producing an alloyed hot-dip galvanized steel sheet having excellent corrosion resistance after painting, and (2) making the Fe% in the plating film after the alloying treatment 10% by weight or more, and using the alkaline aqueous solution. After treatment,
The method for producing an alloyed hot-dip galvanized steel sheet having excellent post-paint corrosion resistance according to the above (1), wherein the steel sheet is subjected to a chromate treatment.
【００１１】[0011]
【作用】次に、本発明において各処理条件を上述のよう
に限定した理由を詳細に説明する。なお、本発明におい
て溶融亜鉛めっき処理および合金化処理それ自体は特に
制限はなく、慣用手段でもって行えばよく、以下の説明
にあっては割愛する。Next, the reason why each processing condition is limited as described above in the present invention will be described in detail. In the present invention, the hot-dip galvanizing treatment and the alloying treatment per se are not particularly limited, and may be performed by conventional means, and are omitted in the following description.
【００１２】鋼帯の機械特性値を調整する調質圧延時の
ロールの粗さは、一般には、1.5 〜3.5 μm 程度である
が、本発明によれば、表面粗さRaで2.5 μm 以下に限定
する。表面粗さが2.5 μm 超では、圧延時にめっき層内
部まで深く掘り起こされるため、めっき表面が電位的に
不均一になるためである。なお、Raの測定については例
えばJIS B0601 に準じて行えばよい。The roughness of the roll during temper rolling for adjusting the mechanical property value of the steel strip is generally about 1.5 to 3.5 μm, but according to the present invention, the surface roughness Ra is 2.5 μm or less. limit. If the surface roughness is more than 2.5 μm, the material is dug deep into the plating layer during rolling, and the plating surface becomes non-uniform in potential. The measurement of Ra may be performed according to, for example, JIS B0601.
【００１３】このような平滑ロールを用いて行う調質圧
延に際し、スキンパス伸び率は0.8％以下とする。スキ
ンパス伸び率が0.8 ％を越えると、めっき層の表面部の
加工が大きくなり、めっき皮膜のクラックが増え、内部
の合金層が表面に現れる割合が増えるため電位的に不均
一となるためである。なお、従来の調質圧延では一般に
0.5〜2.0 ％の伸び率で圧延が行われている。In the temper rolling performed using such a smooth roll, the skin pass elongation is set to 0.8% or less. If the skin pass elongation exceeds 0.8%, the processing of the surface of the plating layer becomes large, cracks in the plating film increase, and the proportion of the inner alloy layer appearing on the surface increases, resulting in non-uniform potential. . Generally, in conventional temper rolling,
Rolling is performed at an elongation of 0.5 to 2.0%.
【００１４】調質圧延後には合金化めっき層の表面部に
形成された酸化物層を一部または全部溶解するためにア
ルカリ処理を行うが、その場合のアルカリ処理用のアル
カリ性溶液のpHは12以上、好ましくは13以上が良い。pH
が12未満であれば合金化めっき層の表面部に濃化した酸
化物が充分に除去されないためである。After the temper rolling, alkali treatment is performed to partially or completely dissolve the oxide layer formed on the surface of the alloyed plating layer. In this case, the pH of the alkaline solution for alkali treatment is 12 Above, preferably 13 or more. pH
If the ratio is less than 12, oxides concentrated on the surface of the alloyed plating layer cannot be sufficiently removed.
【００１５】また、上記アルカリ溶液にはNiおよび/ ま
たはCoを添加しておき、それらをめっき層表面に析出さ
せる。このようにして析出しがNiおよび／またはCoはめ
っき表層の電位を貴にし、耐食性向上の作用をする。こ
のときのNi、Coの濃度は錯化剤、処理温度、処理時間に
もよるが、金属量換算で0.01重量％以上、0.5 重量％以
下とする。0.01％未満であれば、ほとんどNi、Coが置換
析出しない。また、0.5 ％超であれば、Ni、Coが金属と
して置換析出し、かえってめっき表面が電位的に不均一
となり、特に粉体塗装用途等でのクロメート処理された
未塗装面で亜鉛の白錆が発生しやすくなるためである。
なお、Niおよび/ またはCoの添加形態は特に制限されな
いが、例えばキレート化することによって安定してアル
カリ溶液に溶解させてもよい。Further, Ni and / or Co are added to the above-mentioned alkaline solution, and these are deposited on the surface of the plating layer. The Ni and / or Co deposited in this manner makes the potential of the plating surface layer noble and acts to improve the corrosion resistance. The concentration of Ni and Co at this time depends on the complexing agent, the treatment temperature and the treatment time, but is 0.01% by weight or more and 0.5% by weight or less in terms of metal amount. If it is less than 0.01%, Ni and Co hardly displace and precipitate. On the other hand, if it exceeds 0.5%, Ni and Co are substituted and precipitated as metal, and the plating surface becomes non-uniform in terms of potential. Especially, zinc rust on uncoated surface which has been subjected to chromate treatment in powder coating application etc. This is because it is likely to occur.
The addition form of Ni and / or Co is not particularly limited, but it may be stably dissolved in an alkaline solution by, for example, chelation.
【００１６】本発明の好適態様によれば、めっき皮膜中
のFe％は10重量％以上が好ましい。10重量％より少ない
と、σ1 層(FeZn7) とζ層( FeZn13) あるいは合金化条
件によってはη相が混在する。めっき皮膜中に電位の異
なる相が混在すると、腐食過程において局部電池を形成
し、電位の卑なζ相、η相は優先的に腐食し、塗装後の
腐食におけるフクレ幅が、本発明にかかる製造法にあっ
ても、場合によっては大きくなると考えられるからであ
る。According to a preferred embodiment of the present invention, the content of Fe in the plating film is preferably at least 10% by weight. If less than 10 wt%, depending sigma 1 layer (FeZn 7) and ζ layer (FeZn 13) or alloying conditions η phase are mixed. When phases with different potentials are mixed in the plating film, a local battery is formed in the corrosion process, the ζ phase and the η phase with a lower potential are preferentially corroded, and the blister width in the corrosion after coating is determined by the present invention. This is because even in the manufacturing method, it is considered that the size may increase in some cases.
【００１７】なお、ここに言うFe含有量は、合金化めっ
き層の平均値である。合金化めっき層のFe含有量を10％
以上とするには、例えば合金化処理時間、温度を調整す
ることで行うことができるが、その他、めっき浴中Al量
の手段でもってFe含有量を調整してもよい。The Fe content mentioned here is an average value of the alloyed plating layer. Fe content of alloyed plating layer is 10%
The above can be achieved by, for example, adjusting the alloying treatment time and temperature. Alternatively, the Fe content may be adjusted by means of the amount of Al in the plating bath.
【００１８】本発明の別の好適態様によれば、アルカリ
処理後にはクロメート処理を行うことによってさらに裸
および塗装後の耐食性が改善される。この場合のクロメ
ート処理も、特に制限されず、慣用手段でもって行えば
よい。例えば、塗布法によって、ＳｉＯ２ ゾル粒子を分
散含有するクロム酸溶液を塗布乾燥するようにして行え
ばよい。According to another preferred embodiment of the present invention, the chromate treatment is performed after the alkali treatment to further improve the corrosion resistance after naked and after painting. The chromate treatment in this case is not particularly limited, and may be performed by a conventional means. For example, by a coating method, may be performed in a chromic acid solution containing dispersed SiO 2 zone Le particles so that coating and drying.
【００１９】このようにして製造された合金化溶融亜鉛
めっき鋼板は、そのままあるいは、次いで、適宜塗装
(例: 電着塗装、粉体塗装) を行ってから、自動車用あ
るいは家電用に用いることができる。次に、実施例によ
って本発明をさらに具体的に示す。The alloyed hot-dip galvanized steel sheet manufactured as described above may be used as it is, or as appropriate.
(Example: electrodeposition coating, powder coating), and then used for automobiles or home appliances. Next, the present invention will be described more specifically by way of examples.
【００２０】[0020]
【実施例１】出発鋼板の合金化溶融亜鉛めっき鋼板とし
ては、慣用手段でもって溶融亜鉛めっきおよび合金化処
理を行って得た、合金化めっき皮膜中のFe％が9.8 重量
％の極低炭素鋼板 (板厚 0.8mm、めっき付着量45g/m2)
を用いた。Example 1 As an alloyed hot-dip galvanized steel sheet of a starting steel sheet, an ultra-low carbon alloy containing 9.8% by weight of Fe% in an alloyed coating film obtained by performing hot-dip galvanizing and alloying treatment by conventional means. Steel plate (sheet thickness 0.8mm, coating weight 45g / m 2 )
Was used.
【００２１】この合金化溶融亜鉛めっき鋼板を、表１に
示すスキンパス条件、Ni、Coアルカリ処理条件で処理し
た後、日本ペイント製リン酸亜鉛化成処理剤 (商品名:S
D2500MZ)を用いた標準条件で行い、さらに日本ペイント
製の電着塗装剤( 商品名:U−52) を20μm 厚さで塗装
し、さらに、中塗り( 塗料0T04830) 30 μm 、上塗り
(塗料OTO4630) 30 μm をそれぞれ施した。After treating this alloyed hot-dip galvanized steel sheet under the skin pass conditions and Ni, Co alkaline treatment conditions shown in Table 1, a zinc phosphate chemical conversion treatment agent (trade name: S
D2500MZ) under standard conditions, further apply Nippon Paint electrodeposition coating agent (trade name: U-52) with a thickness of 20 μm, and further apply a middle coat (paint 0T04830) 30 μm, top coat
(Paint OTO4630) 30 μm each was applied.
【００２２】得られた電着塗装鋼板から試験片を採取
し、その表面を幅0.1 mmでクロスカットして下記の塩水
噴霧→乾燥→湿潤のサイクル試験に供した。45サイクル
終了後、クロスカット部からの最大フクレ幅で耐外面錆
性を評価した。フクレ幅1.5mm以下を合格とした。A test piece was sampled from the obtained electrodeposition coated steel sheet, and the surface thereof was cross-cut with a width of 0.1 mm and subjected to the following salt spray → dry → wet cycle test. After the completion of 45 cycles, the outer rust resistance was evaluated at the maximum blister width from the cross cut portion. A blister width of 1.5 mm or less was accepted.
【００２３】[0023]
【数１】 (Equation 1)
【００２４】なお、Ni、Coはそれぞれの塩化物をエチレ
ンジアミンでキレートさせたものを用い、NaOHでpH調整
を行った。Ni and Co were prepared by chelating respective chlorides with ethylenediamine, and the pH was adjusted with NaOH.
【００２５】[0025]
【表１】 [Table 1]
【００２６】[0026]
【実施例２】実施例１と同様にして得ためっき皮膜中の
Fe％が８〜12％の低炭素鋼板 (板厚0.5mm、めっき付着
量35g/m2) を出発鋼板として用いた。Fe含有量の調整は
合金化処理時間を調整して行った。次いで、表２に示す
条件で調質圧延およびアルカリ性溶液での処理を行って
から、SiO2含有クロメート処理 (Cr付着量: 35 mg/m2)
を施した後、ポリエステル粉体塗装 (膜厚: 50μm)し、
塗装鋼板を得た。Example 2 In the plating film obtained in the same manner as in Example 1,
A low carbon steel sheet having a Fe% of 8 to 12% (sheet thickness 0.5 mm, coating weight 35 g / m 2 ) was used as a starting steel sheet. The Fe content was adjusted by adjusting the alloying treatment time. Next, after temper rolling and treatment with an alkaline solution were performed under the conditions shown in Table 2, SiO 2 -containing chromate treatment (Cr adhesion amount: 35 mg / m 2 )
After applying, polyester powder coating (film thickness: 50μm),
A coated steel plate was obtained.
【００２７】得られた塗装鋼板から試験片を採取し、そ
の表面を幅0.1 mmでクロスカット後、塩水噴霧試験 (35
℃ NaCl スプレー 500Hr) を行った後、クロスカット部
からの塗膜最大フクレ幅を測定した。結果を同じく表２
にまとめて示す。A test piece was sampled from the obtained coated steel sheet, and the surface thereof was cross-cut with a width of 0.1 mm.
After spraying NaCl spray at 500 ° C), the maximum blister width of the coating film from the cross cut portion was measured. Table 2 also shows the results
Are shown together.
【００２８】[0028]
【表２】 [Table 2]
【００２９】[0029]
【発明の効果】本発明によれば、塗装後耐食性が従来の
ものと比較して大幅に改善され、しかも安定して高い耐
食性が得られることが分かる。特に、合金化めっき層の
Fe含有量を10重量％以上とすることによって塗装後耐食
性は大幅に改善される。According to the present invention, it is understood that the corrosion resistance after coating is greatly improved as compared with the conventional one, and that a high corrosion resistance can be stably obtained. In particular, for alloyed plating layers
By setting the Fe content to 10% by weight or more, the corrosion resistance after painting is greatly improved.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平４−143291（ＪＰ，Ａ) 特開 平２−258962（ＪＰ，Ａ) 特開 平２−274857（ＪＰ，Ａ) 特開 昭54−124838（ＪＰ，Ａ) 特開 昭59−177381（ＪＰ，Ａ) 特開 昭62−20880（ＪＰ，Ａ) 特公 昭43−12974（ＪＰ，Ｂ１) ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-143291 (JP, A) JP-A-2-258962 (JP, A) JP-A-2-274857 (JP, A) JP-A-54-1979 124838 (JP, A) JP-A-59-177381 (JP, A) JP-A-62-20880 (JP, A) JP-B-43-12974 (JP, B1)
Claims (2)
って、溶融亜鉛めっき鋼板の合金化処理後、表面粗さRa
＝2.5 μm 以下のロールを用いて伸び率 0.8％以下の調
質圧延を行い、次いでNiおよびCoの一種または二種を合
計で0.01重量％以上0.5 重量％以下含有するpH＝12以上
のアルカリ性水溶液で処理することを特徴とする、塗装
後耐食性に優れた合金化溶融亜鉛めっき鋼板の製造法。1. A method for producing an alloyed hot-dip galvanized steel sheet, comprising the steps of:
= Temper rolling with elongation of 0.8% or less using rolls of 2.5 µm or less, and then an alkaline aqueous solution of pH 12 or more containing one or two types of Ni and Co in total of 0.01% to 0.5% by weight. A method for producing an alloyed hot-dip galvanized steel sheet having excellent corrosion resistance after painting, characterized in that the steel sheet is treated with a coating.
重量％以上とするとともに、前記アルカリ性水溶液によ
る処理後、クロメート処理する、請求項１記載の塗装後
耐食性に優れた合金化溶融亜鉛めっき鋼板の製造法。2. The Fe% in the plating film after the alloying treatment is reduced to 10%.
The method for producing an alloyed hot-dip galvanized steel sheet having excellent corrosion resistance after coating according to claim 1, wherein the content is not less than% by weight and chromate treatment is performed after the treatment with the alkaline aqueous solution.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4135075A JP2697485B2 (en) | 1992-05-27 | 1992-05-27 | Manufacturing method of high corrosion resistant galvannealed steel sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4135075A JP2697485B2 (en) | 1992-05-27 | 1992-05-27 | Manufacturing method of high corrosion resistant galvannealed steel sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05331662A JPH05331662A (en) | 1993-12-14 |
| JP2697485B2 true JP2697485B2 (en) | 1998-01-14 |
Family
ID=15143262
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4135075A Expired - Fee Related JP2697485B2 (en) | 1992-05-27 | 1992-05-27 | Manufacturing method of high corrosion resistant galvannealed steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2697485B2 (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54124838A (en) * | 1978-03-23 | 1979-09-28 | Kawasaki Steel Co | Production of one side gulvanized steel plate |
| JPS6220880A (en) * | 1985-07-19 | 1987-01-29 | Nippon Parkerizing Co Ltd | Surface treatment of zinc-aluminum alloy plated steel sheet |
| JPH02258962A (en) * | 1989-03-30 | 1990-10-19 | Nippon Steel Corp | Equipment for producing galvanizing steel sheet having excellent weldability |
| JPH0673681B2 (en) * | 1989-04-18 | 1994-09-21 | 川崎製鉄株式会社 | Manufacturing method of high function surface roughness adjustment alloyed hot dip plated steel sheet |
| JPH0776439B2 (en) * | 1990-10-03 | 1995-08-16 | 株式会社神戸製鋼所 | Method for producing double-layer alloyed hot-dip galvanized steel sheet |
-
1992
- 1992-05-27 JP JP4135075A patent/JP2697485B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05331662A (en) | 1993-12-14 |
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