JPS63111163A - Production of hot dip galvanized steel strip - Google Patents
Production of hot dip galvanized steel stripInfo
- Publication number
- JPS63111163A JPS63111163A JP25675686A JP25675686A JPS63111163A JP S63111163 A JPS63111163 A JP S63111163A JP 25675686 A JP25675686 A JP 25675686A JP 25675686 A JP25675686 A JP 25675686A JP S63111163 A JPS63111163 A JP S63111163A
- Authority
- JP
- Japan
- Prior art keywords
- steel strip
- hot
- dip galvanized
- galvanized steel
- plating
- 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
- 229910001335 Galvanized steel Inorganic materials 0.000 title claims abstract description 21
- 239000008397 galvanized steel Substances 0.000 title claims abstract description 21
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 46
- 239000010959 steel Substances 0.000 claims abstract description 46
- 238000001816 cooling Methods 0.000 claims abstract description 25
- 238000007747 plating Methods 0.000 claims description 48
- 238000005246 galvanizing Methods 0.000 claims description 4
- 238000005096 rolling process Methods 0.000 abstract description 9
- 238000010422 painting Methods 0.000 abstract description 8
- 239000000463 material Substances 0.000 abstract description 4
- 230000007797 corrosion Effects 0.000 abstract description 3
- 238000005260 corrosion Methods 0.000 abstract description 3
- 239000010410 layer Substances 0.000 description 31
- 239000013078 crystal Substances 0.000 description 23
- 238000005452 bending Methods 0.000 description 22
- 238000000137 annealing Methods 0.000 description 11
- 238000012360 testing method Methods 0.000 description 10
- 239000011248 coating agent Substances 0.000 description 9
- 238000000576 coating method Methods 0.000 description 9
- 230000015572 biosynthetic process Effects 0.000 description 7
- 238000001953 recrystallisation Methods 0.000 description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 6
- 229910052802 copper Inorganic materials 0.000 description 6
- 239000010949 copper Substances 0.000 description 6
- 238000005336 cracking Methods 0.000 description 6
- 238000005097 cold rolling Methods 0.000 description 5
- 238000005098 hot rolling Methods 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 239000003973 paint Substances 0.000 description 5
- 239000011701 zinc Substances 0.000 description 5
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 4
- 229910052725 zinc Inorganic materials 0.000 description 4
- 230000007547 defect Effects 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 2
- 239000010960 cold rolled steel Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 241000519995 Stachys sylvatica Species 0.000 description 1
- 229910001297 Zn alloy Inorganic materials 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000002050 diffraction method Methods 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000010309 melting process Methods 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Coating With Molten Metal (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は塗装後の曲げ加工の際に生じるめっき層や塗膜
の割れを極力回避するのに有利な塗装鋼板の下地用鋼板
に適する溶融亜鉛めっき鋼帯の製造方法に関するもので
ある。Detailed Description of the Invention (Industrial Field of Application) The present invention is a melting process suitable for a base steel plate of a coated steel plate, which is advantageous in avoiding as much as possible cracks in the plating layer and coating film that occur during bending after painting. The present invention relates to a method for producing galvanized steel strip.
（従来の技術）
溶融亜鉛めっき鋼帯に連続塗装ラインで塗装を施した塗
装鋼帯は屋根、壁材などの建材或いは家電製品容器等に
使用されている。(Prior Art) Painted steel strips, which are hot-dip galvanized steel strips coated on a continuous coating line, are used for building materials such as roofs and wall materials, containers for home appliances, and the like.
従来塗装鋼板となる溶融亜鉛めっき鋼板は塗装後の表面
外観が亜鉛めっき面の凹凸、面方位により不均一になる
ことを避けるため、スパングルを出来るだけ細かくする
ことが好ましいとされている（特開昭５８−４８６５７
号公報、特公昭６０−５５５９３号公報参照）。It is said that it is preferable to make the spangles as fine as possible for hot-dip galvanized steel sheets, which are conventionally painted steel sheets, in order to avoid unevenness of the surface appearance after painting due to irregularities and surface orientation of the galvanized surface. Showa 58-48657
(See Japanese Patent Publication No. 60-55593).
ところでこのような溶融亜鉛めっき鋼帯を通用した塗装
鋼板を、かかる用途に使用する場合以下の如き問題があ
った。However, when a coated steel sheet that has been used as a hot-dip galvanized steel strip is used for such purposes, there are the following problems.
すなわち、塗装鋼板に曲げ加工を施すと、曲げ加工のめ
っき層および塗膜に割れが生じ、耐食性や外観が著しく
損なわれる。That is, when a painted steel sheet is subjected to bending, cracks occur in the plating layer and coating film resulting from the bending, which significantly impairs corrosion resistance and appearance.
例えばｐｂを０．０５％以上含有させためっき浴にて処
理しためっき鋼帯は、めっき後の冷却条件によってスパ
ングルを極力小さくすることが可能で、塗装後の表面外
観を改善することができるが、スパングルが小さくなる
程加工時に割れが発生しやすい不利があった。For example, for plated steel strips treated with a plating bath containing 0.05% or more of PB, spangles can be minimized by changing the cooling conditions after plating, and the surface appearance after painting can be improved. However, the smaller the spangle, the more likely it is that cracks will occur during processing.
このため従来では塗膜自体の加工性の改善を図ったり、
あるいはめっき処理におけるｐｂの低減と、めっき後の
冷却条件を種々に組合わせた処理を施し、スパングルの
より一層の微細化を図った上で曲げ加工時に発生する割
れを防止していた。For this reason, conventional efforts have been made to improve the workability of the coating film itself,
Alternatively, various combinations of Pb reduction during plating and post-plating cooling conditions have been applied to further refine the spangles and prevent cracks that occur during bending.
（発明が解決しようとする問題点）
しかし従来の方法では、曲げ加工により塗膜やめっき層
の微細な割れを防止するのが困難で塗膜の硬質化の妨げ
になったり、曲げ加工で割れの発生を避けるように曲げ
半径が制限されていたので製品デザインに制約がある等
、不十分な点が指摘されていたのが現状であった。(Problem to be solved by the invention) However, with the conventional method, it is difficult to prevent minute cracks in the coating film or plating layer due to bending, which hinders hardening of the coating, or cracks caused by bending. At present, inadequacies were pointed out, such as the bending radius being limited to avoid the occurrence of blemishes, which placed constraints on the product design.
本発明の目的は、スパングルがより微細であると同時に
曲げ加工を施しても上述した如き問題のない塗装鋼板の
素地に適した溶融亜鉛めっき鋼帯の製造方法を提案する
ところにある。An object of the present invention is to propose a method for manufacturing a hot-dip galvanized steel strip that has finer spangles and is suitable for use as a base material for coated steel sheets, which does not cause the above-mentioned problems even when subjected to bending.
（問題点を解決するための手段）
本発明者らは溶融亜鉛めっき鋼板の曲げ加工時の割れ発
生挙動を種々検討した結果、めっきを構成する亜鉛結晶
の結晶方位が（００１）／／板面となっている場合に割
れが発生し易く、めっき後亜鉛めっき層が凝固する際に
（００１）／／板面なる方位の結晶の生成、成長を抑制
することにより、塗装した後の鋼板の加工時に生じる塗
膜やめっき層の割れを効果的に回避し得ることを見出し
た。(Means for Solving the Problems) As a result of various studies on cracking behavior during bending of hot-dip galvanized steel sheets, the present inventors found that the crystal orientation of the zinc crystals constituting the coating was (001)//sheet surface. Cracks are likely to occur when the galvanized layer solidifies after coating, and by suppressing the formation and growth of crystals in the (001)// plate surface orientation, processing of the steel plate after painting is improved. It has been found that cracks in paint films and plating layers that sometimes occur can be effectively avoided.
すなわち本発明は、塗装鋼板の下地鋼板に適した溶融亜
鉛めっき鋼帯を製造するに際し、７００℃〜Ａｒ、の温
度域で熱間仕上圧延を施した鋼帯を、冷間圧延し、つい
で焼鈍を経てからＰｂ ： ０．０５％以下、４１：０
．１〜０．３％を含有する溶融亜鉛めっき浴中に浸漬通
板させてめっき処理を施したのち、少なくとも４１０℃
〜３００℃の温度域を冷却速度２０’Ｃ／ｓ以上で冷却
することを特徴とする溶融亜鉛めっき鋼帯の製造方法で
ある。That is, when manufacturing a hot-dip galvanized steel strip suitable as a base steel sheet for painted steel sheets, the present invention cold-rolls a steel strip that has been hot finish rolled in a temperature range of 700°C to Ar, and then anneales it. Pb after passing through: 0.05% or less, 41:0
．． After plating by immersing the plate in a hot-dip galvanizing bath containing 1 to 0.3%, at least 410℃
This is a method for producing a hot-dip galvanized steel strip, characterized by cooling in a temperature range of ~300°C at a cooling rate of 20'C/s or more.
（作 用）
めっき層における亜鉛の結晶方位を（００１）／／板面
とならないようにするためには素地鋼板の最表面層の再
結晶焼鈍後の結晶方位として（１１１）／／板面となる
ものを極力少なくしておく必要がある。(Function) In order to prevent the crystal orientation of zinc in the plating layer from becoming (001) // sheet surface, the crystal orientation after recrystallization annealing of the outermost layer of the base steel sheet should be set to (111) // sheet surface. It is necessary to minimize the number of things that occur.
すなわち素地鋼板の表面層の結晶方位が（１１１）／／
板面であると、めっき層中に（００１）／／板面となる
結晶が多くなり易く、このため曲げ加工でのめっき層割
れが発生し易くなる。In other words, the crystal orientation of the surface layer of the base steel sheet is (111)//
If it is a plate surface, there are likely to be many crystals forming the (001)//plate surface in the plating layer, which makes it easy for the plating layer to crack during bending.
そこでまず、素地鋼板の製造工程において、被圧延材を
７００℃〜Ａｒ＝の温度域で熱間仕上げ圧延する。Therefore, first, in the manufacturing process of the base steel plate, the material to be rolled is hot finish rolled in a temperature range of 700° C. to Ar=.
上記温度域で熱間仕上圧延するのは、再結晶焼鈍後の調
帯の表面近傍に（１１１）／／板面方位の結晶の形成を
防止するためである。熱間仕上圧延温度がＡｒ＝を超、
える場合にはその効果が小さく、逆に７００℃未満では
調帯表面に酸化物の噛込みが多くなり不めっき、白点等
のめっき欠陥の発生原因となる。The reason why hot finish rolling is performed in the above temperature range is to prevent the formation of crystals with (111)//plate plane orientation near the surface of the toning zone after recrystallization annealing. The hot finish rolling temperature exceeds Ar=,
On the other hand, if the temperature is lower than 700° C., oxides will be trapped on the surface of the strip, causing plating defects such as unplated spots and white spots.
次に、熱間圧延して得られた調帯を好ましくは圧下率４
０％〜９５％の範囲で冷間圧延する。Next, the toning obtained by hot rolling is preferably carried out at a rolling reduction rate of 4
Cold rolling is performed in the range of 0% to 95%.
冷間圧延における圧下率により、再結晶焼鈍後の調帯の
集合組織は変化することが知られているが、７００℃〜
Ａｒ３点の温度域で熱間仕上圧延した鋼帯の最表面層の
結晶方位は、冷間圧延での圧下率によらず、（１１１）
／／板面となる結晶の形成が十分抑制される。It is known that the texture of the strip after recrystallization annealing changes depending on the reduction rate during cold rolling, but
The crystal orientation of the outermost layer of a steel strip hot finish rolled in the Ar3 temperature range is (111), regardless of the reduction rate in cold rolling.
//The formation of crystals forming the plate surface is sufficiently suppressed.
圧下率は、経済的な合理性を満足する範囲として４０％
〜９５％に設定する。The rolling reduction rate is 40%, which satisfies economic rationality.
Set to ~95%.
冷間圧延された鋼帯は引続き焼鈍工程に供給して再結晶
温度〜９００℃の温度域で所定の時間焼鈍する。The cold-rolled steel strip is subsequently fed to an annealing process and annealed at a temperature ranging from the recrystallization temperature to 900° C. for a predetermined period of time.
焼鈍工程における鋼帯のｍ織は再結晶と同時に結晶方位
が定まるが、優先的に成長する結晶方位は、焼鈍条件に
よって変化する。The crystal orientation of the m-weave of the steel strip in the annealing process is determined at the same time as recrystallization, but the crystal orientation that grows preferentially changes depending on the annealing conditions.
しかし再結晶後における銅帯の最表面層の結晶方位は焼
鈍温度によってはほとんど変化せず熱間仕上圧延温度が
前述した範囲であれば上記温度域の焼鈍にて（１１０）
／／板面や（１００）／／板面とすることができ（１１
１）／／板面となる結晶は極めて少ない。However, the crystal orientation of the outermost layer of the copper strip after recrystallization hardly changes depending on the annealing temperature, and if the hot finish rolling temperature is within the above range, annealing in the above temperature range (110)
//Plate surface or (100) //Plate surface (11
1) // There are very few crystals that form plate surfaces.
焼鈍温度は再結晶温度以上であって鋼帯の形状が保たれ
得る９００℃以下の範囲に設定するのが望ましい。It is desirable that the annealing temperature be set in a range that is higher than the recrystallization temperature and lower than 900° C. so that the shape of the steel strip can be maintained.
次に焼鈍工程を経た鋼帯をめっき処理するが、溶融亜鉛
めっき浴に含有するｐｂおよびＡｌｌはそれぞれ０．０
５％以下、０．１〜０．３％に調整する必要がある。Next, the steel strip that has undergone the annealing process is plated, and the PB and All contained in the hot-dip galvanizing bath are each 0.0
It is necessary to adjust it to 5% or less, 0.1 to 0.3%.
ｐｂはとくにスパングルの大きさを制御するためにめっ
き浴中に添加する元素であるが、塗装鋼板の下地用の溶
融亜鉛めっき鋼帯を得る場合、スパングルが極力小さく
でき、かつ曲げ加工の際に塗膜やめっき層の割れを防止
する必要がある。そのためにはめっき処理後の急冷によ
り十分細かいスパングルが得られかつ加工時において割
れが発生し難いめっき層が得られる範囲でｐｂは可及的
に少ない方が好ましい。かかる目的に合致するｐｂの含
有量は０．０５％以下である。PB is an element added to the plating bath to control the size of spangles, but when obtaining a hot-dip galvanized steel strip for the base of painted steel sheets, it is necessary to minimize the spangles and to reduce the amount of spangles during bending. It is necessary to prevent cracks in the paint film and plating layer. For this purpose, it is preferable that the amount of PB be as small as possible within the range that sufficiently fine spangles can be obtained by rapid cooling after plating and a plating layer that is difficult to crack during processing can be obtained. The content of PB that meets this purpose is 0.05% or less.
Ａｌは、めっき処理した鋼帯のめっき層が凝固するまで
の間に、めっき層を形成する溶融金属中にＦｅが溶出し
て鋼帯表面とめっき層界面にＦｅ −Ｚｎ合金層が形成
されることによって、めっき層の密着性が劣化するのを
防止するために添加する元素である。そのためにはめっ
き浴中にＡｌｌを０．１％以上添加する必要がある。と
ころで０．３％を超えるとドロス欠陥等のめっき欠陥が
発生しやすくなる。よってＡｎの含有量は０．１〜０．
３％の範囲に限定した。In Al, until the plating layer of the plated steel strip solidifies, Fe is eluted into the molten metal that forms the plating layer, and a Fe-Zn alloy layer is formed at the interface between the steel strip surface and the plating layer. This element is added to prevent the adhesion of the plating layer from deteriorating. For this purpose, it is necessary to add 0.1% or more of All into the plating bath. However, if it exceeds 0.3%, plating defects such as dross defects are likely to occur. Therefore, the content of An is 0.1 to 0.
It was limited to a range of 3%.
上述した如き成分調整されためっき浴に銅帯を浸漬通板
させる。そして必要量以上に付着した溶融金属を気体払
拭装置で取除いてめっき目付量を８周整する。The copper strip is immersed and passed through a plating bath whose composition has been adjusted as described above. Then, the molten metal that has adhered in excess of the required amount is removed by a gas wiping device, and the plating area weight is adjusted 8 times.
次にめっき処理を終えた銅帯を少なくとも４２０℃〜３
００℃の温度域で急冷する。めっき処理後の銅帯を上記
温度域で冷却することによりスパングルの微細化を図り
、かつ（００１）／／板面方位の結晶の形成を効果的に
抑制することが可能となる。Next, the copper strip after the plating treatment is plated at a temperature of at least 420℃~3
Rapid cooling in the temperature range of 00°C. By cooling the copper strip after plating in the above temperature range, it is possible to make spangles finer and to effectively suppress the formation of crystals with (001)//plate plane orientation.
このような急冷による効果を十分発揮させるためには冷
却速度を２０℃／ｓ以上にする必要がある。In order to fully exhibit the effect of such rapid cooling, it is necessary to set the cooling rate to 20° C./s or more.
ここで、めっき処理する前の銅帯の（１１１）／／板面
となる結晶を少なくし、めっき処理後所定の条件で冷却
することで（００１）／／板面になる結晶の形成を抑制
できる機構については明らかでないが、以下のように推
定される。Here, by reducing the number of crystals that will become the (111) // plate surface of the copper strip before plating, and cooling it under predetermined conditions after plating, the formation of crystals that will become the (001) // plate surface is suppressed. Although the mechanism by which this occurs is not clear, it is presumed as follows.
Ｆｅの（１１１）面上には亜鉛の（００１）面が発達し
易く、例えばめっき処理後の冷却速度が小さい場合、亜
鉛めっき層の凝固は最も放熱し易い最表面と、調帯から
Ｆｅが溶出して融点の上昇した鋼帯−めっき層界面より
始まるためとくに鋼帯の結晶方位の影響を受は易いもの
と考えられる。すなわち（ＩＩＩ）／／板面となってい
るＦｅ結晶上に（００１）／／板面になるめっき層が形
成され易い。The (001) plane of zinc is likely to develop on the (111) plane of Fe. For example, if the cooling rate after plating is slow, the galvanized layer will solidify on the outermost surface where heat is most easily dissipated, and on the top surface where Fe will dissipate most easily. Since it begins at the steel strip-plating layer interface where the melting point has increased due to elution, it is thought that it is particularly susceptible to the influence of the crystal orientation of the steel strip. In other words, a plating layer having a (001) // plate surface is easily formed on the Fe crystal having a (III) // plate surface.
ところでめっき処理前の鋼帯表面近傍における（１１１
）／／板面方位の結晶の形成をあらかじめ抑制し、めっ
き処理後所定の条件で急冷すれば亜鉛めっき層の凝固が
主に最表面より起こるので銅帯の結晶方位に影響されず
ランダムな方位の結晶を形成することができる。従って
（００１）／／板面なる方位の亜鉛結晶の形成を極力抑
制できるのである。By the way, (111
)//If the formation of crystals in the sheet surface orientation is suppressed in advance and the galvanized layer is rapidly cooled under predetermined conditions after plating, solidification of the galvanized layer will occur mainly from the outermost surface, resulting in random orientation without being affected by the crystal orientation of the copper strip. crystals can be formed. Therefore, the formation of zinc crystals in the (001)// plate plane orientation can be suppressed to the utmost.
（実施例）
表−１に示す化学成分よりなる鋼を用い種々の条件で溶
融亜鉛めっき鋼帯を製造した。(Example) Hot-dip galvanized steel strips were manufactured under various conditions using steel having the chemical components shown in Table-1.
表−１
（ｗｔ％）
鋼１は低炭素鋼で、冷却速度２０℃／ｓで冷却した時、
変形なしの状態で測定したＡｒ３点は約８２０℃であっ
た。また鋼２は極低炭素鋼で同様の条件で測定したＡｒ
３点は８６０℃であった。Table 1 (wt%) Steel 1 is a low carbon steel, and when cooled at a cooling rate of 20°C/s,
The temperature at three Ar points measured without deformation was about 820°C. Steel 2 is an ultra-low carbon steel with Ar measured under the same conditions.
The temperature at 3 points was 860°C.
鋼ｌを熱間圧延するに際しては、熱延仕上温度を７７０
℃と８６０℃、鋼２を熱間圧延するに際しては熱延仕上
温度を８８０℃、８２０℃と、それぞれ２条件で熱間圧
延し、計４種の板厚２．８龍の熱延鋼板を得た。これら
熱延鋼板を冷延するに際しては、低温（７７０℃、８２
０℃）で熱延したものは仕上げ板厚を０．３．０．７お
よび１．２１１とし、高温（８６０℃。When hot rolling steel l, the hot rolling finishing temperature is set to 770.
When hot rolling Steel 2, hot rolling was carried out under two conditions: 880°C and 820°C, respectively, and a total of four types of hot rolled steel sheets with a thickness of 2.8°C were obtained. Obtained. When cold rolling these hot-rolled steel sheets, low temperatures (770°C, 82°C
The finished plate thicknesses of those hot-rolled at 0.3, 0.7 and 1.211 were applied at high temperature (860°C).
８８０℃）で熱延したものは０．７Ｂのみに圧延し、計
８種の冷延鋼板を得た。板厚０．３．０．７および１．
２鶴の冷延圧下率はそれぞれ８９％、７５％、５７％で
ある。Those hot-rolled at 880° C.) were rolled to only 0.7B to obtain a total of 8 types of cold-rolled steel sheets. Plate thickness 0.3, 0.7 and 1.
The cold rolling reduction ratios of Nitsuru are 89%, 75%, and 57%, respectively.
次に連続式溶融亜鉛めっき設備でこれらの鋼板に焼鈍、
及びめっき処理を施した。焼鈍温度はすべて７５０℃と
し、均熱時間は、それぞれの板厚に応じて０．３鶴の時
３０ｓｅｃ、 ０．７鶴の時４０ｓｅｃ 。Next, these steel plates are annealed using continuous hot-dip galvanizing equipment.
and plating treatment. The annealing temperature was 750°C in all cases, and the soaking time was 30 sec for 0.3 tsuru and 40 sec for 0.7 tsuru, depending on the thickness of each plate.
１．２鶴の時６０ｓｅｃとした。1. When the crane was 2, it was set to 60 seconds.
まためっき浴の組成は、ＡＣを０．１５％、ｐｂを０６
０２％含有する浴とし、めっき目付量はすべて２５０ｇ
／ｍ２とした。目付量を制御するための気体払拭後、ク
ーリングタワー中に設けた冷却設備でそれぞれ自然放冷
（Ａ）、衝風冷却（Ｇ）、および気水冷却（Ｍ）を施し
た。The composition of the plating bath was 0.15% AC and 0.6% PB.
The bath contains 0.02%, and the plating weight is 250g.
/m2. After wiping off the gas to control the basis weight, natural cooling (A), blast cooling (G), and air/water cooling (M) were performed using cooling equipment installed in the cooling tower.
冷却速度は７℃／ｓ〜６０″Ｃｐｓの範囲で調節した。The cooling rate was adjusted in the range of 7°C/s to 60″Cps.
その後得られた溶融亜鉛めっき鋼帯に圧下率０．５％の
調質圧延を施して製品とし、これら製品より幅４０ｎ×
長さ５０鶴の試験片を採取して曲げ試験によるめっき層
の割れ特性を調べた。After that, the obtained hot-dip galvanized steel strip was subjected to temper rolling with a reduction rate of 0.5% to produce products, and these products were made into products with a width of 40n×
A test piece with a length of 50 cranes was taken and the cracking characteristics of the plating layer were examined by bending test.
曲げ試験は試験片を密着曲げ加工し、曲げ加工部に発生
する割れを４段階評価（１良−４悪）した。In the bending test, the test piece was subjected to close bending, and cracks occurring in the bent portion were evaluated on a four-grade scale (1 good to 4 bad).
さらにこれら亜鉛めっき鋼板にリン酸塩処理を施した後
ポリエステル系のプライマーおよびトップコートで塗装
後試験片を採取して曲げ試験により塗膜割れ挙動を調べ
た。曲げ試験はめっき後の曲げと同様密着曲げ加工を施
し割れ発生の有無（Ｏ×）を調べた。Further, these galvanized steel sheets were subjected to phosphate treatment, and then coated with a polyester primer and top coat, test pieces were taken and the cracking behavior of the paint film was investigated by a bending test. In the bending test, a close bending process was performed in the same manner as the bending after plating, and the presence or absence of cracking (Ox) was examined.
表−２に溶融亜鉛めっき鋼帯の製造条件および曲げ試験
結果をそれぞれ示す。また参考としてＺｎ粉末としてＸ
線回折法により求めためっき層の（００１）面強度比を
併せ示す。Table 2 shows the manufacturing conditions and bending test results for the hot-dip galvanized steel strip. Also, as a reference, X as Zn powder
The (001) plane intensity ratio of the plating layer determined by the line diffraction method is also shown.
めっき処理後における冷却速度が２０°Ｃ／ｓ未満の場
合には、鋼１、！１ｉ１２にかかわらず亜鉛めっき層の
（００１）面強度比は３以上でありめっき層に割れが多
く発生し、塗装後においても割れが発生した。If the cooling rate after plating is less than 20°C/s, steel 1,! Regardless of 1i12, the (001) plane strength ratio of the galvanized layer was 3 or more, and many cracks occurred in the plating layer, and cracks also occurred after painting.
また熱間仕上圧延温度がＡｒ３点を超えたものについて
はめっき後の冷却速度が２０℃／ｓ以上であっても（０
０１）面強度比は５．０以上であり上記同様にめっき層
の割れが多く塗装後においても割れが発生した。In addition, for those whose hot finish rolling temperature exceeds the Ar3 point, even if the cooling rate after plating is 20°C/s or more (0
01) The surface strength ratio was 5.0 or more, and similarly to the above, there were many cracks in the plating layer, and cracks occurred even after painting.
本発明を適用したものについては、冷却速度が大きくな
る程（００１）面強度比が小さくなる傾向にあり、めっ
き後の曲げ試験および塗装後の曲げ試験において割れが
全く発生せず、めっき層の（００１）面の発達を抑制す
ることによってめっき層や塗膜の割れを効果的に防止で
きることが確かめられた。Regarding the products to which the present invention is applied, the (001) surface strength ratio tends to decrease as the cooling rate increases, and no cracks occur in the bending test after plating or the bending test after painting, and the plating layer It was confirmed that cracking of the plating layer and paint film can be effectively prevented by suppressing the development of the (001) plane.
（発明の効果）
本発明によればスパングルをより微細にした上で曲げ加
工時におけるめっき層や塗膜の割れを完全に防止できる
塗装鋼板の下地鋼板に適した溶融亜鉛めっき鋼帯を製造
することが可能で、このようなめっき鋼帯を適用した塗
装鋼板においては加工部の外観が損なわれず耐食性を著
しく改善することができる。また塗装鋼板に用いる塗料
の種類も従来に比べ大幅に増加することができる。(Effects of the Invention) According to the present invention, a hot-dip galvanized steel strip suitable for a base steel sheet of a coated steel sheet can be produced, which has finer spangles and can completely prevent cracking of the plating layer or coating film during bending. In a coated steel sheet to which such a plated steel strip is applied, the appearance of the processed portion is not impaired and the corrosion resistance can be significantly improved. Furthermore, the types of paints used for painted steel sheets can be significantly increased compared to conventional methods.
Claims (1)
製造するに際し、 ７００℃〜Ａｒ＿３の温度域で熱間仕上圧延を施した鋼
帯を、冷間圧延しついで焼鈍を経てから、Ｐｂ：０．０
５％以下、Ａｌ：０．１〜０．３％を含有する溶融亜鉛
めっき浴中に浸漬通板させてめっき処理を施したのち、
少なくとも４２０℃〜３００℃の温度域を冷却速度２０
℃／ｓ以上で冷却することを特徴とする溶融亜鉛めっき
鋼帯の製造方法。[Claims] 1. When producing a hot-dip galvanized steel strip suitable as a base steel plate for painted steel sheets, a steel strip that has been hot finish rolled in a temperature range of 700°C to Ar_3 is cold rolled and then annealed. After passing through, Pb: 0.0
After performing plating treatment by immersing the plate in a hot-dip galvanizing bath containing 5% or less and Al: 0.1 to 0.3%,
Cooling rate 20 in the temperature range of at least 420℃~300℃
A method for producing a hot-dip galvanized steel strip, characterized by cooling at a rate of ℃/s or higher.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61256756A JPH0610332B2 (en) | 1986-10-30 | 1986-10-30 | Method for manufacturing steel strip with fused zinc plating |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61256756A JPH0610332B2 (en) | 1986-10-30 | 1986-10-30 | Method for manufacturing steel strip with fused zinc plating |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63111163A true JPS63111163A (en) | 1988-05-16 |
| JPH0610332B2 JPH0610332B2 (en) | 1994-02-09 |
Family
ID=17297007
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61256756A Expired - Fee Related JPH0610332B2 (en) | 1986-10-30 | 1986-10-30 | Method for manufacturing steel strip with fused zinc plating |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0610332B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2019505666A (en) * | 2015-12-22 | 2019-02-28 | ポスコＰｏｓｃｏ | Hot-dip galvanized steel sheet with excellent surface quality and low-temperature brittle fracture resistance |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6033318A (en) * | 1983-08-01 | 1985-02-20 | Kawasaki Steel Corp | Manufacture of high tensile strength hot-dip zinc-coated caron steel sheet efficient in bending workability |
| JPS6055592A (en) * | 1983-09-07 | 1985-03-30 | Hitachi Ltd | Semiconductor device |
-
1986
- 1986-10-30 JP JP61256756A patent/JPH0610332B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6033318A (en) * | 1983-08-01 | 1985-02-20 | Kawasaki Steel Corp | Manufacture of high tensile strength hot-dip zinc-coated caron steel sheet efficient in bending workability |
| JPS6055592A (en) * | 1983-09-07 | 1985-03-30 | Hitachi Ltd | Semiconductor device |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2019505666A (en) * | 2015-12-22 | 2019-02-28 | ポスコＰｏｓｃｏ | Hot-dip galvanized steel sheet with excellent surface quality and low-temperature brittle fracture resistance |
| US11078564B2 (en) | 2015-12-22 | 2021-08-03 | Posco | Hot-dip galvanized steel sheet with excellent surface quality and resistance to low temperature brittle fracture |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0610332B2 (en) | 1994-02-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104755647A (en) | Hot-dip galvanized steel sheet | |
| KR890001829B1 (en) | Hot dip zinc plated basin | |
| KR20150073315A (en) | HOT DIP Zn-Al-Mg ALLOY PLATED STEEL SHEET HAVING EXCELLENT CORROSION RESISTANCE AND METHOD FOR MANUFACTURING THE SAME | |
| JPH0324255A (en) | Hot-dip galvanized hot rolled steel plate and its production | |
| JP3052822B2 (en) | Micro spangle hot-dip Zn-Al alloy coated steel sheet and its manufacturing method | |
| JPH11140587A (en) | Galvannealed steel sheet excellent in plating adhesion | |
| JPS63111163A (en) | Production of hot dip galvanized steel strip | |
| JP3159135B2 (en) | Micro spangle hot-dip galvanized steel sheet and manufacturing method | |
| JPH0124221B2 (en) | ||
| JPH0559489A (en) | Cold rolled steel sheet for deep drawing as well as galvanized product thereof and there manufacturing method | |
| JP2004124118A (en) | Galvanized steel sheet having excellent press formability and appearance and method for manufacturing the same | |
| JP3654520B2 (en) | Surface-treated steel sheet excellent in workability and corrosion resistance of machined part and method for producing the same | |
| JP3749487B2 (en) | Surface-treated steel sheet excellent in workability and corrosion resistance of machined part | |
| JP3205292B2 (en) | Manufacturing method of hot-dip galvanized steel sheet with excellent corrosion resistance and plating adhesion | |
| JP3371819B2 (en) | Hot-dip galvanized steel sheet excellent in blackening resistance and method for producing the same | |
| JPH10140316A (en) | Production of hot dip galvanized steel sheet excellent in workability | |
| JP3643559B2 (en) | Surface-treated steel sheet excellent in workability and corrosion resistance of machined part and method for producing the same | |
| JPH08269662A (en) | Production of zinc-tin alloy coated steel sheet | |
| JP2002249862A (en) | Surface treated steel sheet having excellent workability nd corrosion resistance in worked part, and production method therefor | |
| JPS62182260A (en) | Manufacture of hot dip galvanized steel sheet | |
| KR20010112968A (en) | The method of high image clarity alloyed hot dip galvanized steel for outcase of automobile | |
| KR0128126B1 (en) | Manufacturing method of hot dip zinc coated steel sheet | |
| JP2998642B2 (en) | Manufacturing method of galvannealed steel sheet | |
| JPH04378A (en) | Alloyed molten zinc plates steel sheet having superior outside and inside corrosion resistance | |
| JPH05320850A (en) | Production of galvannealed steel sheet having excellent powdering resistance and weldability |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| LAPS | Cancellation because of no payment of annual fees |