JPS6330984B2 - - Google Patents
Info
- Publication number
- JPS6330984B2 JPS6330984B2 JP56183653A JP18365381A JPS6330984B2 JP S6330984 B2 JPS6330984 B2 JP S6330984B2 JP 56183653 A JP56183653 A JP 56183653A JP 18365381 A JP18365381 A JP 18365381A JP S6330984 B2 JPS6330984 B2 JP S6330984B2
- Authority
- JP
- Japan
- Prior art keywords
- corrosion resistance
- plating
- bath
- present
- 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.)
- Expired
Links
- 229910001335 Galvanized steel Inorganic materials 0.000 claims description 18
- 239000008397 galvanized steel Substances 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 18
- 239000011701 zinc Substances 0.000 claims description 16
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 15
- 229910052725 zinc Inorganic materials 0.000 claims description 15
- 239000011777 magnesium Substances 0.000 claims description 9
- 229910052782 aluminium Inorganic materials 0.000 claims description 6
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 229910052749 magnesium Inorganic materials 0.000 claims description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 4
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 3
- 239000012535 impurity Substances 0.000 claims description 2
- 238000005260 corrosion Methods 0.000 description 34
- 230000007797 corrosion Effects 0.000 description 34
- 238000007747 plating Methods 0.000 description 28
- 239000000047 product Substances 0.000 description 19
- 239000000203 mixture Substances 0.000 description 12
- 238000005246 galvanizing Methods 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 10
- 238000000576 coating method Methods 0.000 description 7
- 238000001816 cooling Methods 0.000 description 7
- 239000011248 coating agent Substances 0.000 description 6
- 238000005096 rolling process Methods 0.000 description 6
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 238000005275 alloying Methods 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 239000013078 crystal Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910001327 Rimmed steel Inorganic materials 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 238000007664 blowing Methods 0.000 description 2
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 230000005496 eutectics Effects 0.000 description 2
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 description 2
- 229910052745 lead Inorganic materials 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 229910001297 Zn alloy Inorganic materials 0.000 description 1
- 229910007570 Zn-Al Inorganic materials 0.000 description 1
- 238000010306 acid treatment Methods 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000003466 anti-cipated effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000007429 general method Methods 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 239000012943 hotmelt Substances 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000010422 painting Methods 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011265 semifinished product Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000010301 surface-oxidation reaction Methods 0.000 description 1
- 238000011179 visual inspection Methods 0.000 description 1
- 230000004580 weight loss Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- 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
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
- C23C2/06—Zinc or cadmium or alloys based thereon
-
- C—CHEMISTRY; METALLURGY
- 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
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/26—After-treatment
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C18/00—Alloys based on zinc
- C22C18/04—Alloys based on zinc with aluminium as the next major constituent
-
- C—CHEMISTRY; METALLURGY
- 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
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/26—After-treatment
- C23C2/28—Thermal after-treatment, e.g. treatment in oil bath
-
- C—CHEMISTRY; METALLURGY
- 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
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/34—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
- C23C2/36—Elongated material
- C23C2/40—Plates; Strips
Description
本発明は耐食性、塗装性に優れた溶融亜鉛めつ
き鋼板の製造法に関する。
近年溶融亜鉛めつき鋼板は従来の屋根、壁用の
素材から、自動車部材あるいは塗装を目的とした
プレコート用素材へとその用途が多様化、高級化
しつつある。即ちその加工製品に優れた表面外観
と形状が要求されるので、厳しい曲げ加工、絞り
加工などにおいて、素材の加工性はもとよりめつ
き層の加工性、加工部のめつき層の耐食性が一段
と良好な製品への要求が高まつている。
従来、耐食性の向上は亜鉛付着量を増加させる
方法と、めつき亜鉛そのものの耐食性を高めるた
めに亜鉛浴に対する他元素を添加する方法が種々
検討されている。
前者は亜鉛の鉄地に対する保薄作用は増加する
反面、加工部分のめつき層にクラツクが起りやす
く、めつき層の剥離を生じたり、さらに表面外観
の低下を起こすなどの実用上の欠点がかなり大き
い。
後者に関しては、例えば、アメリカ合衆国特許
第4029478号に、Al：0.2〜17％、Mg：0.003〜
0.15％、Pb：0.02〜0.15％を含有する亜鉛浴の使
用が提案されている。この亜鉛合金浴の使用は耐
食性の点ではかなり効果が認められるが、詳細に
検討した結果は、Al、Mg、Pbなどの添加元素の
量的バランスに若干難点があるためか、耐食性も
不充分であり、塗装性の面でも欠点があることが
確認された。その理由はPbの量がやや高いこと、
Pb量に比較してMg量が少ないことが原因である
と推定される。
また、亜鉛めつき鋼板の表面外観の向上、およ
び機械的性質等の向上を目的に、一般的手段とし
て、めつき後、溶融亜鉛が凝固する直前に、ミス
ト冷却によつて亜鉛結晶粒を微細化したり、めつ
き後、レベラー加工と調質圧延との組合わせによ
つて表面を平滑化したりすることが行なわれてい
る。しかし、めつき層を急速冷却や機械的手段で
平滑化させることは腐食に対する活性点を増すこ
とであり、耐食性の面から必ずしも好ましくな
く、特に調質圧延などは過度に行なうことは禁物
である。
さらに、プレコート原板、あるいは自動車用素
材としての使用を考慮した場合、加工の面から絞
り性、溶接性などが重要な要件となり、その点で
は、めつき層の厚さは薄い程効果的であるから、
極薄目付でしかも高耐食性を具備することが要求
される。近年、溶融めつきにおいては、めつき厚
さの制御は気体吹拭方式が採られており、しかも
高速操業（160〜200ｍ／min）で行なわれてい
る。このような高速操業下では、現行の亜鉛めつ
き浴組成（Al：0.15〜0.18％）で、付着量45〜60
ｇ／m2（片面以下同じ）の範囲であり、加工の面
から目標とされる30ｇ／m2以下の程度の極薄付着
量は達成されていない。付着量を低下させるため
に一般に採られているのは、めつき速度を標準よ
り20〜30％低下させて、ガスワイピングによる吹
拭効果を利用するものであるが、これは生産性を
低下させて工業的に好ましい手段ではない。
本発明者等は、上記の諸問題を解決すべく研究
を重ねた結果、問題解決の要点は基本的にはめつ
き浴の性質にあることを認識して本発明に到達し
た。
本発明によれば、溶融亜鉛めつき鋼板の製造に
おいて、アルミニウム0.35〜3.0％、マグネシウ
ム0.15〜1.0％を含有し、鉛含有量が0.015％以下
で、残部亜鉛および不可避的不純物からなる浴を
用いることを特徴とする溶融亜鉛めつき鋼板の製
造方法が提供される。
前記のような組成の亜鉛めつき浴は使用された
ことがない。
本発明は次の諸特徴を有する。
１ 製品の耐食性は現行のAlを0.15〜0.18％含有
する亜鉛浴から得られるものに比較して３倍以
上である。
２ めつき浴通過後、特別に急速冷却せずにミニ
マイズドスパングルを有する平滑なものが得ら
れる。
３ めつき後、軽度の調質圧延（圧下率１％前
後）を施すことにより、表面外観の極めて優れ
た、機械的性質の良好な製品が得られる。
４ 亜鉛めつき浴の組成において、アルミニウム
濃度が2.5〜20倍に高めた結果、同一温度で浴
の流動性が増し、同一ガスワイピング条件で吹
拭効果が増大し、極薄付着量の製品が得られ
る。
次に本発明方法に使用する亜鉛めつき浴の組成
の限定理由について述べる。
１ アルミニウム
溶融亜鉛浴中のAlの濃度は増加するに従つ
て同一温度における流動性は現行浴より１段と
増大する。現行浴のAl濃度は0.15％程度である
が0.3％を越えると、流動性は現行浴の1.5〜2.0
倍程度に上昇する。それ故本発明の浴ではその
下限を0.35％とした。また上限は、3.0％を越
えるとZn−Alの共晶組織が顕著となり、共晶
部位と亜鉛との間で局部電池が構成され、耐食
性の低下の原因となるため3.0％を上限とした。
２ マグネシウム
Mgは耐食性を向上させる目的で添加される
元素の１つであるが、含有量0.15％近傍から生
成めつき層の耐食性が顕著に良好になる。Mg
の増加とともに耐食性はさらに増大するが、そ
の濃度は1.0％を越えると製品のめつき層外観
がシワ状となる劣化や表面の酸化が顕著になり
だすとともに、めつき浴表面の酸化（ドロスの
生成）が盛になり浴を消耗する結果となる。従
つてMgの含有量は0.15〜1.0％と限定される。
３ 鉛
PbのZn中への固溶限は常温で殆んどなく通
常結晶粒内、粒界に微細な粒状で晶出し、局部
電池を構成し、耐食性低下の原因の１つとなつ
ている。この意味からPb含有量は低い程好ま
しい。検討を重ねた結果Pb濃度0.015％以下で
は、めつき層において微視的にめつき層粒界、
粒間においてその存在が殆んど検出できず、実
際上の耐食性もこの濃度以下なら粒界における
腐食も殆んど認められず、さらに亜鉛の結晶ス
パングルも肉眼的に殆んど認められず、表面の
平滑なめつき表面外観であることなど確認して
Pb含有量は0.015％以下と定めた。
この組成の亜鉛めつき浴の使用により、現行の
操業条件で、めつき付着量が30ｇ／m2以下の極薄
付着量で、優れた耐食性と表面外観を有する溶融
亜鉛めつき鋼板が得られる。
なお極薄付着量は本発明の特徴の１つであるけ
れども、付着量はガスワイピングの条件を変化さ
せることで変化させることができ、厚付着も当然
に可能である。
本発明方法の浴を用いてめつき後、めつき鋼板
を加熱処理することによつて合金化亜鉛めつき鋼
板が得られるが、現行の亜鉛めつき浴を使用した
めつき鋼板に比し、一段と耐食性の良好な亜鉛め
つき鋼板が得られることが確認されている。合金
化のための加熱条件は通常の合金化条件でよく、
例えば、雰囲気温度550℃〜1200℃、２〜30秒加
熱すればよい。
また自動車部材に使用される片面亜鉛めつき鋼
板を、めつき阻止剤法によつて試作したものにつ
いても、耐食性、加工性ともに優れたものが得ら
れることが確認されている。
本発明方法による亜鉛めつき鋼板は、従来の屋
根、壁等の用途はもとより、プレコートカラー用
の半製品、自動車用部材、家電用材料のみなら
ず、将来的に種々の工業分野での利用が期待さ
れ、その工業的利用価値は極めて高い。
次に本発明を実施例によりさらに具体的に説明
する。
実施例 １
次の表１に示す組成の亜鉛めつき浴を用いて、
板厚0.4mm、板巾300mmの未焼鈍リムド鋼鋼板に、
ガス還元方式溶融めつき設備で、次の条件で、亜
鉛めつきを施した、
前処理条件
無酸化炉出口側板温 590〜600℃
還元炉 ガス組成 H2：75％、N2：25％
〃 出口側板温 700〜720℃
めつき浴温度 460℃±５℃
めつき厚さ：亜鉛付着量片面120ｇ／m2
めつき後処理
調質圧延なし
クロム酸後処理なし
製品の特性検査の方法および結果の評価は次の
通りである。
スパングルのサイズ：目視
めつき密着性：ロツクフオーミング加工し、加工
後加工部をセロテープ剥離試験し剥離の有無を
見る。剥離しないものを「良好」とする。
粒間、粒界のPbの存在状態：走査電子顕微鏡に
よる組成像によつて判定（大、中、小、微）
耐食性：
(1) 塩水噴霧試験（JIS Ｚ−2371）によつて赤錆
発生までの時間を測定
(2) 塩水噴霧試験（JIS Ｚ−2371）200時間後の
腐食減量（ｇ／m2）測定
The present invention relates to a method for manufacturing hot-dip galvanized steel sheets with excellent corrosion resistance and paintability. In recent years, the uses of hot-dip galvanized steel sheets have been diversifying and becoming more sophisticated, from conventional materials for roofs and walls to pre-coating materials for automobile parts and painting purposes. In other words, the processed product is required to have an excellent surface appearance and shape, so in severe bending, drawing, etc., not only the workability of the material but also the workability of the plated layer and the corrosion resistance of the plated layer of the processed part are improved. There is an increasing demand for products with Conventionally, various methods have been studied to improve corrosion resistance, including increasing the amount of zinc deposited, and adding other elements to the zinc bath in order to increase the corrosion resistance of the plated zinc itself. The former has practical disadvantages, such as increasing the thinning effect of zinc on the iron base, but cracks in the plating layer on processed parts, causing peeling of the plating layer, and further deteriorating the surface appearance. Quite large. Regarding the latter, for example, in U.S. Pat. No. 4,029,478, Al: 0.2-17%, Mg: 0.003-
It is proposed to use a zinc bath containing 0.15%, Pb: 0.02-0.15%. Although the use of this zinc alloy bath is recognized to be quite effective in terms of corrosion resistance, the results of a detailed study revealed that the corrosion resistance is also insufficient, probably due to some difficulties in the quantitative balance of additive elements such as Al, Mg, and Pb. It was confirmed that there were also drawbacks in terms of paintability. The reason is that the amount of Pb is somewhat high,
It is presumed that the cause is that the amount of Mg is small compared to the amount of Pb. In addition, for the purpose of improving the surface appearance and mechanical properties of galvanized steel sheets, as a general method, after plating, just before the molten zinc solidifies, zinc crystal grains are made fine by mist cooling. After plating, the surface is smoothed by a combination of leveling and temper rolling. However, smoothing the plated layer by rapid cooling or mechanical means increases the number of active points for corrosion, which is not necessarily desirable in terms of corrosion resistance, and excessive heat rolling is especially prohibited. . Furthermore, when considering use as a pre-coated original sheet or a material for automobiles, drawability, weldability, etc. are important requirements from a processing perspective, and in this respect, the thinner the plated layer is, the more effective it is. from,
It is required to have an extremely thin basis weight and high corrosion resistance. In recent years, in hot melt plating, a gas wiping method has been adopted to control the plating thickness, and the process is carried out at high speed (160 to 200 m/min). Under such high-speed operation, with the current galvanizing bath composition (Al: 0.15-0.18%), the coating weight is 45-60%.
g/m 2 (same for one side and below), and the ultra-thin adhesion amount of 30 g/m 2 or less, which is the target from the processing perspective, has not been achieved. The common method to reduce the amount of plating is to reduce the plating speed by 20 to 30% from the standard and utilize the wiping effect of gas wiping, but this reduces productivity. This is not an industrially preferred method. As a result of repeated research aimed at solving the above-mentioned problems, the present inventors realized that the key to solving the problems basically lies in the properties of the plating bath, and arrived at the present invention. According to the present invention, in the production of hot-dip galvanized steel sheets, a bath containing 0.35-3.0% aluminum, 0.15-1.0% magnesium, and a lead content of 0.015% or less, with the balance consisting of zinc and inevitable impurities, is used. A method for manufacturing a hot-dip galvanized steel sheet is provided. A galvanizing bath of such composition has never been used. The present invention has the following features. 1. The corrosion resistance of the product is more than three times that obtained from current zinc baths containing 0.15-0.18% Al. 2. After passing through the plating bath, a smooth product with minimized spangles can be obtained without special rapid cooling. 3. After plating, a light temper rolling (reduction ratio of around 1%) is performed to obtain a product with an extremely excellent surface appearance and good mechanical properties. 4 In the composition of the galvanizing bath, the aluminum concentration was increased by 2.5 to 20 times, which increased the fluidity of the bath at the same temperature, increased the wiping effect under the same gas wiping conditions, and produced products with extremely thin coatings. can get. Next, the reasons for limiting the composition of the galvanizing bath used in the method of the present invention will be described. 1 Aluminum As the concentration of Al in the molten zinc bath increases, the fluidity at the same temperature increases by one step compared to the current bath. The Al concentration of the current bath is about 0.15%, but if it exceeds 0.3%, the fluidity will be 1.5 to 2.0% of the current bath.
It will rise to about twice as much. Therefore, in the bath of the present invention, the lower limit was set at 0.35%. Moreover, the upper limit was set at 3.0% because if it exceeds 3.0%, the eutectic structure of Zn-Al will become noticeable and a local battery will be formed between the eutectic site and zinc, causing a decrease in corrosion resistance. 2 Magnesium Mg is one of the elements added for the purpose of improving corrosion resistance, and the corrosion resistance of the formed plated layer becomes significantly better when the content is around 0.15%. Mg
Corrosion resistance further increases as the concentration increases, but when the concentration exceeds 1.0%, the appearance of the plating layer of the product becomes wrinkled, the surface oxidation becomes noticeable, and the surface of the plating bath becomes oxidized (dross). (formation) will increase and the bath will be consumed. Therefore, the Mg content is limited to 0.15 to 1.0%. 3. Lead There is almost no solid solubility limit for Pb in Zn at room temperature, and it usually crystallizes in fine grains within crystal grains and at grain boundaries, forming local batteries and being one of the causes of reduced corrosion resistance. In this sense, the lower the Pb content, the better. As a result of repeated studies, when the Pb concentration is 0.015% or less, the plating layer grain boundaries and
Its existence is almost undetectable between grains, and in terms of actual corrosion resistance, below this concentration, corrosion at grain boundaries is hardly observed, and zinc crystal spangles are hardly visible to the naked eye. Check that the surface is smooth and has a smooth surface appearance.
The Pb content was set at 0.015% or less. By using a galvanizing bath with this composition, under current operating conditions, hot-dip galvanized steel sheets with an extremely thin coating weight of 30 g/m 2 or less and excellent corrosion resistance and surface appearance can be obtained. . Although an extremely thin coating amount is one of the features of the present invention, the coating amount can be changed by changing the gas wiping conditions, and a thick coating is naturally also possible. An alloyed galvanized steel sheet can be obtained by heat-treating the plated steel sheet after plating using the bath of the present invention, but compared to the galvanized steel sheet using the current galvanizing bath, It has been confirmed that galvanized steel sheets with even better corrosion resistance can be obtained. The heating conditions for alloying may be normal alloying conditions;
For example, heating may be performed at an ambient temperature of 550°C to 1200°C for 2 to 30 seconds. It has also been confirmed that single-sided galvanized steel sheets used for automobile parts produced by the galvanization inhibitor method have excellent corrosion resistance and workability. Galvanized steel sheets produced by the method of the present invention can be used not only for conventional roofing and wall applications, but also for semi-finished products for pre-coated colors, automobile parts, and home appliance materials, as well as for various industrial fields in the future. It is highly anticipated that its industrial utility value is extremely high. Next, the present invention will be explained in more detail with reference to Examples. Example 1 Using a galvanizing bath having the composition shown in Table 1 below,
Made of unannealed rimmed steel plate with a thickness of 0.4 mm and a width of 300 mm.
Galvanizing was performed using gas reduction hot-dip galvanizing equipment under the following conditions. Pretreatment conditions Non-oxidation furnace outlet side plate temperature 590-600℃ Reduction furnace Gas composition H 2 : 75%, N 2 : 25% 〃 Outlet side plate temperature 700-720℃ Plating bath temperature 460℃±5℃ Plating thickness: Zinc deposit 120g/m on one side 2 Post-plating treatment No skin-pass rolling No chromic acid post-treatment Method and results of product characteristic inspection The evaluation is as follows. Spangle size: Visual inspection Adhesion: Lock forming processing is performed, and after processing, the processed part is subjected to a sellotape peel test to check for peeling. Those that do not peel off are considered "good." Presence of Pb between grains and grain boundaries: Determined by composition image using a scanning electron microscope (large, medium, small, fine) Corrosion resistance: (1) Until red rust occurs by salt spray test (JIS Z-2371) (2) Measurement of corrosion weight loss (g/m 2 ) after 200 hours of salt spray test (JIS Z-2371)
【表】【table】
【表】
表１には試験を浴組成とともにまとめて示して
ある。以下、表の記載について本発明方法による
製品とそれ以外の製法（比較例）の製品の性質を
比較して説明する。
１ スパングルサイズ
本発明方法による製品は、めつき後放冷した
にもかかわらず微細なスパングルを呈し、表中
の評価「微少」は目視では殆んど識別し得ない
もので、表面外観は全く平滑であつた。一方比
較例ではNo.10の試料が強制冷却（水冷）によつ
てスパングル小となつている以外、放冷ではい
ずれも中〜大であり、目視で明瞭なスパングル
が認められた。なお比較例はいずれも水冷によ
つてスパングル微細化するが均一性が劣ること
が多かつたり、また水冷しない場合明瞭なスパ
ングルが存在することもあつて表面の凹凸はか
なりのものである。従つてこれら表面を平滑化
させるには調質圧延をかなり強化する必要が生
じてくる。
２ めつき密着性
密着性そのものは本発明、比較例ともに特に
問題はなかつたが、曲げ加工部のめつき層のク
ラツキングは本発明の製品では極めて少く、微
少程度であるのに対して、比較例の製品では粒
界、粒間にかなり大きなめつき層のクラツキン
グが検知され、この点で本発明の製品は良好で
あつた。
３ 粒界、粒間におけるPbの存在状態
亜鉛めつき鋼板における腐食の発生の原因の
１つと考えられる粒界、粒間におけるPbの存
在は、浴のPb含有量を0.015％以下に限定した
結果、量的には微〜少程度で、走査電子顕微鏡
組成像においても殆んど目立たない。これに対
し、比較例ではPb含有量が高いために、試料
No.14以外は粒状で、粒界、粒内におけるPbの
存在は明瞭であつた。
４ 耐食性
本発明の製品はすべて赤錆発生までの時間が
1000時間以上であり、かつ腐食減量においても
30ｇ／m2未満であつた。一方比較例の製品は、
比較的良好なものNo.11で800時間、劣悪なもの
No.10、12では200時間未満であり、腐食減量に
おいても本発明製品の２〜６倍程度であつた。
実施例 ２
表２に示す組成の溶融亜鉛めつき浴を用いて、
実施例１と同じめつき装置で、下記の条件で極薄
目付亜鉛めつき鋼板を製造し、特性を調べた。
原板：板厚0.4mmのリムド鋼
前処理条件：実施例１に同じ
めつき厚さ−気体吹拭条件（一定）
ガス圧力 0.35Kg／cm2
ノズル高さ 浴面から150mm
ノズル間隔 ストリツプ〜ノズル先端間６mm
めつき後処理
調質圧延なし
クロム酸処理なし[Table] Table 1 summarizes the tests along with the bath composition. Hereinafter, the description in the table will be explained by comparing the properties of products produced by the method of the present invention and products produced by other production methods (comparative examples). 1 Spangle Size The product produced by the method of the present invention exhibits fine spangles even though it is left to cool after plating, and the "slight" rating in the table means that they are almost impossible to discern with the naked eye, and the surface appearance is completely It was smooth and warm. On the other hand, in Comparative Example, except for sample No. 10, which had small spangles due to forced cooling (water cooling), all spangles were medium to large when left to cool, and clear spangles were visually observed. In all of the comparative examples, spangles are made finer by water cooling, but the uniformity is often poor, and when water cooling is not done, clear spangles are sometimes present and the surface is quite uneven. Therefore, in order to smooth these surfaces, it becomes necessary to considerably intensify the temper rolling. 2. Plating adhesion There was no particular problem with the adhesion itself in both the present invention and the comparative example, but the cracking of the plating layer at the bending part was extremely small and only slight in the product of the present invention, whereas in the comparative example In the product of the example, considerable cracking of the plating layer at grain boundaries and between grains was detected, and the product of the present invention was good in this respect. 3 Existence of Pb at grain boundaries and intergranules The presence of Pb at grain boundaries and intergranules, which is considered to be one of the causes of corrosion in galvanized steel sheets, is the result of limiting the Pb content in the bath to 0.015% or less. The amount is minute to small, and it is hardly noticeable even in a scanning electron microscope composition image. On the other hand, in the comparative example, due to the high Pb content, the sample
All samples except No. 14 were granular, and the presence of Pb at the grain boundaries and within the grains was clear. 4 Corrosion resistance All products of the present invention have a long time until red rust appears.
More than 1000 hours and corrosion loss
It was less than 30g/ m2 . On the other hand, the comparative example product is
800 hours on relatively good No. 11, poor one
For Nos. 10 and 12, the time was less than 200 hours, and the corrosion loss was about 2 to 6 times that of the products of the present invention. Example 2 Using a hot-dip galvanizing bath having the composition shown in Table 2,
Using the same plating apparatus as in Example 1, an ultra-thin galvanized steel sheet was produced under the following conditions, and its properties were investigated. Original plate: Rimmed steel with a thickness of 0.4 mm Pre-treatment conditions: Same plating thickness as in Example 1 - gas blowing conditions (constant) Gas pressure 0.35 Kg/cm 2 nozzle height 150 mm from bath surface Nozzle spacing Strip to nozzle tip Distance 6mm Post-plating treatment No temper rolling No chromic acid treatment
【表】
以下表の記載について本発明方法による製品と
比較例の製品の性質を比較して説明する。
１ めつき付着量
本発明方法では、めつき付着量が片面で10
ｇ／m2前後の極薄目付量であるのに対し、比較
例では、その約２倍以上であることが分かる。
めつき条件が同一であることから、本発明浴は
気体吹拭による厚み制御に非常に効果のある浴
であることが明瞭である。
２ 耐食性
本実施例では付着量が極めて少ないため、耐
食性が懸念されたが、赤錆発生までの時間はNo.
17で270時間、No.16、18で140、180時間と可な
り高耐食性が得られることが確認された。また
赤錆発生面積が全試験面積の約30％を占めるま
での時間はNo.17で840時間、No.16、18が520、
580時間で、腐食の進行は可なり遅く、耐食性
は良好であることが確認された。一方比較例で
は付着量において、本発明に比較してて２倍以
上であるにもかかわらず、No.19で100時間で赤
錆発生面積は30％を越え、目付量の大きいNo.20
でも450時間で30％を越えており、耐食性にお
いても本発明方法が優れていることは明らかで
ある。
実施例 ３
表３に示す組成の溶融亜鉛めつき浴を用いて、
亜鉛めつき鋼板を製造した後、表示する加熱条件
にて合金化処理を施した。得られた合金化亜鉛め
つき鋼板の特性を表３に示す。表３の結果から明
らかなように、本発明に係る亜鉛めつき鋼板は合
金化処理を施した場合従来のものに比べ一層優れ
た耐蝕性を有することが確認できた。[Table] The description in the table below will be explained by comparing the properties of a product produced by the method of the present invention and a product of a comparative example. 1 Plating amount In the method of the present invention, the plating amount is 10 on one side.
It can be seen that the comparative example has an extremely thin basis weight of around g/m 2 , while it is more than twice that.
Since the plating conditions are the same, it is clear that the bath of the present invention is very effective in controlling thickness by gas blowing. 2 Corrosion Resistance In this example, the amount of adhesion was extremely small, so there were concerns about corrosion resistance, but the time until red rust appeared was the highest.
It was confirmed that considerably high corrosion resistance was obtained for 270 hours with No. 17, and 140 and 180 hours with No. 16 and 18. In addition, the time it took for the area where red rust occurred to occupy approximately 30% of the total test area was 840 hours for No. 17, 520 hours for Nos. 16 and 18, and 520 hours for No. 16 and 18.
After 580 hours, it was confirmed that the corrosion progress was quite slow and the corrosion resistance was good. On the other hand, in the comparative example, although the amount of adhesion is more than twice that of the present invention, the area where red rust occurred in No. 19 exceeded 30% in 100 hours, and No. 20 with a large area weight
However, the corrosion resistance exceeded 30% after 450 hours, and it is clear that the method of the present invention is superior in terms of corrosion resistance. Example 3 Using a hot dip galvanizing bath having the composition shown in Table 3,
After producing a galvanized steel sheet, it was subjected to alloying treatment under the indicated heating conditions. Table 3 shows the properties of the obtained alloyed galvanized steel sheet. As is clear from the results in Table 3, it was confirmed that the galvanized steel sheet according to the present invention had better corrosion resistance than the conventional steel sheet when subjected to alloying treatment.
【表】【table】
Claims (1)
ニウム0.35〜3.0％、マグネシウム0.15〜1.0％を
含有し、鉛含有量が0.015％以下で、残部亜鉛お
よび不可避不純物からなる浴を用いることを特徴
とする溶融亜鉛めつき鋼板の製造方法。 ２ 特許請求の範囲第１項記載の方法であつて、
亜鉛付着量が片面30ｇ／m2以下であることを特徴
とする方法。[Claims] 1. In the production of hot-dip galvanized steel sheets, a bath containing 0.35 to 3.0% aluminum, 0.15 to 1.0% magnesium, and a lead content of 0.015% or less, with the balance consisting of zinc and inevitable impurities, is used. A method for producing a hot-dip galvanized steel sheet. 2. The method according to claim 1, comprising:
A method characterized in that the amount of zinc deposited on one side is 30 g/m 2 or less.
Priority Applications (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56183653A JPS5891162A (en) | 1981-11-18 | 1981-11-18 | Manufacture of galvanized steel plate |
| CA000414918A CA1190353A (en) | 1981-11-18 | 1982-11-04 | Process for preparing hot-dip zinc-plated steel sheets |
| AU90229/82A AU540419B2 (en) | 1981-11-18 | 1982-11-08 | Hot dip zinc plated steel sheets |
| KR8205192A KR890001829B1 (en) | 1981-11-18 | 1982-11-17 | Hot dip zinc plated basin |
| GB08232830A GB2110248B (en) | 1981-11-18 | 1982-11-17 | Process for preparing hot dip zinc plated steel sheets |
| DE3242625A DE3242625C2 (en) | 1981-11-18 | 1982-11-18 | Process for the production of hot-dip galvanized steel sheets and hot-dip galvanizing melt |
| FR8219309A FR2537161B1 (en) | 1981-11-18 | 1982-11-18 | PROCESS AND BATH FOR THE PREPARATION OF GALVANIZED STEEL SHEETS BY HOT DIP |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56183653A JPS5891162A (en) | 1981-11-18 | 1981-11-18 | Manufacture of galvanized steel plate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5891162A JPS5891162A (en) | 1983-05-31 |
| JPS6330984B2 true JPS6330984B2 (en) | 1988-06-21 |
Family
ID=16139561
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56183653A Granted JPS5891162A (en) | 1981-11-18 | 1981-11-18 | Manufacture of galvanized steel plate |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS5891162A (en) |
| KR (1) | KR890001829B1 (en) |
| AU (1) | AU540419B2 (en) |
| CA (1) | CA1190353A (en) |
| DE (1) | DE3242625C2 (en) |
| FR (1) | FR2537161B1 (en) |
| GB (1) | GB2110248B (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3375971D1 (en) * | 1982-12-06 | 1988-04-14 | Siemens Ag | Housing for electronic equipments |
| JP2755387B2 (en) * | 1988-04-12 | 1998-05-20 | 大洋製鋼株式会社 | Manufacturing method of hot-dip zinc-alloy-plated steel sheet for pre-coated steel sheet and pre-coated steel sheet |
| JP4173990B2 (en) * | 2002-12-27 | 2008-10-29 | 新日本製鐵株式会社 | Zinc-based alloy-plated steel for welding and its ERW steel pipe |
| CN103320738A (en) | 2004-06-29 | 2013-09-25 | 塔塔钢铁艾默伊登有限责任公司 | Steel sheet with hot dip galvanized zinc alloy coating and process to produce it |
| EP1621645A1 (en) * | 2004-07-28 | 2006-02-01 | Corus Staal BV | Steel sheet with hot dip galvanized zinc alloy coating |
| EP1693477A1 (en) * | 2005-02-22 | 2006-08-23 | ThyssenKrupp Steel AG | Coated steel plate |
| US7413769B2 (en) * | 2005-07-01 | 2008-08-19 | Mcdevitt Erin T | Process for applying a metallic coating, an intermediate coated product, and a finish coated product |
| PL1857566T3 (en) | 2006-05-15 | 2017-10-31 | Thyssenkrupp Steel Europe Ag | Flat steel product provided with a corrosion protection coating and method of its manufacture |
| ES2629109T3 (en) * | 2006-05-15 | 2017-08-07 | Thyssenkrupp Steel Europe Ag | Procedure for the manufacture of a flat steel product coated with a corrosion protection system |
| US8721809B2 (en) | 2007-02-23 | 2014-05-13 | Tata Steel Ijmuiden B.V. | Method of thermomechanical shaping a final product with very high strength and a product produced thereby |
| DE202007006168U1 (en) | 2007-04-19 | 2007-07-19 | Rothfuss, Thomas | Wire grid for wire baskets, has steel core provided with coating that is made from alloy of zinc and aluminum, where coating has specific thickness and alloy is applied on steel core |
| CN105821199B (en) | 2007-07-19 | 2018-09-04 | 穆尔和本德公司 | For the method to annealing in length direction steel band with different thickness |
| DE102007048504B4 (en) | 2007-10-10 | 2013-11-07 | Voestalpine Stahl Gmbh | Anti-corrosion coating for steel sheets and method of conditioning a corrosion protection coating |
| EP2119804A1 (en) * | 2008-05-14 | 2009-11-18 | ArcelorMittal France | Method of manufacturing a covered metal strip with improved appearance |
| KR102568479B1 (en) * | 2017-05-25 | 2023-08-18 | 타타 스틸 이즈무이덴 베.뷔. | Method for producing continuous hot-dip galvanized steel strip and hot-dip galvanized steel sheet |
| DE102020119911B3 (en) | 2020-07-28 | 2021-12-09 | Johannes Hülshorst | Profile tube punch and working method |
| CN112322968A (en) * | 2020-09-28 | 2021-02-05 | 日照钢铁控股集团有限公司 | Thermal-base non-flower high-strength galvanized plate for photovoltaic support and preparation process thereof |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3320040A (en) * | 1963-08-01 | 1967-05-16 | American Smelting Refining | Galvanized ferrous article |
| FR1446872A (en) * | 1964-09-15 | 1966-07-22 | Inland Steel Co | Protective coating made of zinc-based alloys |
| GB1131951A (en) * | 1965-06-08 | 1968-10-30 | Hitachi Ltd | Method of and apparatus for continuous hot dip metal coating |
| US4152472A (en) * | 1973-03-19 | 1979-05-01 | Nippon Steel Corporation | Galvanized ferrous article for later application of paint coating |
| IT984964B (en) * | 1973-05-09 | 1974-11-20 | Centro Speriment Metallurg | ZINC-BASED COATING FOR THE PROTECTION OF IRON SURFACES AND METALLIC BODY FROM CORRO SION IN THIS WAY OBTAINED |
| US4029478A (en) * | 1976-01-05 | 1977-06-14 | Inland Steel Company | Zn-Al hot-dip coated ferrous sheet |
| JPS5641359A (en) * | 1979-09-10 | 1981-04-18 | Nippon Steel Corp | Manufacture of corrosion resistant zinc alloy-plated steel products by galvanizing |
| JPS5696062A (en) * | 1979-12-28 | 1981-08-03 | Nippon Steel Corp | Manufacture of corrosion resistant steel products coated with zinc alloy by hot dipping |
| AU525668B2 (en) * | 1980-04-25 | 1982-11-18 | Nippon Steel Corporation | Hot dip galvanizing steel strip with zinc based alloys |
-
1981
- 1981-11-18 JP JP56183653A patent/JPS5891162A/en active Granted
-
1982
- 1982-11-04 CA CA000414918A patent/CA1190353A/en not_active Expired
- 1982-11-08 AU AU90229/82A patent/AU540419B2/en not_active Ceased
- 1982-11-17 GB GB08232830A patent/GB2110248B/en not_active Expired
- 1982-11-17 KR KR8205192A patent/KR890001829B1/en active
- 1982-11-18 DE DE3242625A patent/DE3242625C2/en not_active Expired
- 1982-11-18 FR FR8219309A patent/FR2537161B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR2537161A1 (en) | 1984-06-08 |
| GB2110248A (en) | 1983-06-15 |
| KR840002463A (en) | 1984-07-02 |
| AU540419B2 (en) | 1984-11-15 |
| JPS5891162A (en) | 1983-05-31 |
| DE3242625C2 (en) | 1985-01-03 |
| FR2537161B1 (en) | 1986-08-08 |
| CA1190353A (en) | 1985-07-16 |
| GB2110248B (en) | 1985-09-25 |
| AU9022982A (en) | 1983-05-26 |
| KR890001829B1 (en) | 1989-05-25 |
| DE3242625A1 (en) | 1983-05-26 |
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