JP2022092815A - Steel sheet for cans and production method thereof - Google Patents
Steel sheet for cans and production method thereof Download PDFInfo
- Publication number
- JP2022092815A JP2022092815A JP2020205743A JP2020205743A JP2022092815A JP 2022092815 A JP2022092815 A JP 2022092815A JP 2020205743 A JP2020205743 A JP 2020205743A JP 2020205743 A JP2020205743 A JP 2020205743A JP 2022092815 A JP2022092815 A JP 2022092815A
- Authority
- JP
- Japan
- Prior art keywords
- chromium
- steel sheet
- cans
- amount
- electrolysis treatment
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 96
- 239000010959 steel Substances 0.000 title claims abstract description 96
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 26
- 239000011651 chromium Substances 0.000 claims abstract description 116
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims abstract description 110
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 110
- 229910052751 metal Inorganic materials 0.000 claims abstract description 25
- 239000002184 metal Substances 0.000 claims abstract description 25
- 238000011282 treatment Methods 0.000 claims description 62
- 238000005868 electrolysis reaction Methods 0.000 claims description 51
- 239000007864 aqueous solution Substances 0.000 claims description 27
- 238000000034 method Methods 0.000 claims description 20
- 239000002245 particle Substances 0.000 claims description 17
- 229910052731 fluorine Inorganic materials 0.000 claims description 13
- 239000011737 fluorine Substances 0.000 claims description 13
- 150000001875 compounds Chemical class 0.000 claims description 12
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 8
- -1 fluorine ions Chemical class 0.000 claims description 7
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 claims description 6
- 230000007797 corrosion Effects 0.000 abstract description 22
- 238000005260 corrosion Methods 0.000 abstract description 22
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 abstract description 3
- 229910000423 chromium oxide Inorganic materials 0.000 abstract 2
- 239000010410 layer Substances 0.000 description 67
- 239000011347 resin Substances 0.000 description 13
- 229920005989 resin Polymers 0.000 description 13
- 239000002585 base Substances 0.000 description 10
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 8
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 239000003513 alkali Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- QQVIHTHCMHWDBS-UHFFFAOYSA-N isophthalic acid Chemical compound OC(=O)C1=CC=CC(C(O)=O)=C1 QQVIHTHCMHWDBS-UHFFFAOYSA-N 0.000 description 4
- 239000002244 precipitate Substances 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 2
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 2
- 238000007334 copolymerization reaction Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- QQVIHTHCMHWDBS-UHFFFAOYSA-L isophthalate(2-) Chemical compound [O-]C(=O)C1=CC=CC(C([O-])=O)=C1 QQVIHTHCMHWDBS-UHFFFAOYSA-L 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000005554 pickling Methods 0.000 description 2
- 229920000139 polyethylene terephthalate Polymers 0.000 description 2
- 239000005020 polyethylene terephthalate Substances 0.000 description 2
- KMUONIBRACKNSN-UHFFFAOYSA-N potassium dichromate Chemical compound [K+].[K+].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O KMUONIBRACKNSN-UHFFFAOYSA-N 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000006722 reduction reaction Methods 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- HEMHJVSKTPXQMS-UHFFFAOYSA-M sodium hydroxide Inorganic materials [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- QLOKJRIVRGCVIM-UHFFFAOYSA-N 1-[(4-methylsulfanylphenyl)methyl]piperazine Chemical compound C1=CC(SC)=CC=C1CN1CCNCC1 QLOKJRIVRGCVIM-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 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
- 238000003854 Surface Print Methods 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 1
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 1
- 235000011130 ammonium sulphate Nutrition 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 235000011132 calcium sulphate Nutrition 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 description 1
- 229910001430 chromium ion Inorganic materials 0.000 description 1
- 229940117975 chromium trioxide Drugs 0.000 description 1
- UOUJSJZBMCDAEU-UHFFFAOYSA-N chromium(3+);oxygen(2-) Chemical class [O-2].[O-2].[O-2].[Cr+3].[Cr+3] UOUJSJZBMCDAEU-UHFFFAOYSA-N 0.000 description 1
- GAMDZJFZMJECOS-UHFFFAOYSA-N chromium(6+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Cr+6] GAMDZJFZMJECOS-UHFFFAOYSA-N 0.000 description 1
- VQWFNAGFNGABOH-UHFFFAOYSA-K chromium(iii) hydroxide Chemical class [OH-].[OH-].[OH-].[Cr+3] VQWFNAGFNGABOH-UHFFFAOYSA-K 0.000 description 1
- QFSKIUZTIHBWFR-UHFFFAOYSA-N chromium;hydrate Chemical compound O.[Cr] QFSKIUZTIHBWFR-UHFFFAOYSA-N 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000005097 cold rolling Methods 0.000 description 1
- 239000012611 container material Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 238000005238 degreasing Methods 0.000 description 1
- SOCTUWSJJQCPFX-UHFFFAOYSA-N dichromate(2-) Chemical compound [O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O SOCTUWSJJQCPFX-UHFFFAOYSA-N 0.000 description 1
- 238000002845 discoloration Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-M hydrogensulfate Chemical compound OS([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-M 0.000 description 1
- 238000010191 image analysis Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000010409 ironing Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- QPJSUIGXIBEQAC-UHFFFAOYSA-N n-(2,4-dichloro-5-propan-2-yloxyphenyl)acetamide Chemical compound CC(C)OC1=CC(NC(C)=O)=C(Cl)C=C1Cl QPJSUIGXIBEQAC-UHFFFAOYSA-N 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 239000012188 paraffin wax Substances 0.000 description 1
- NROKBHXJSPEDAR-UHFFFAOYSA-M potassium fluoride Chemical compound [F-].[K+] NROKBHXJSPEDAR-UHFFFAOYSA-M 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 238000009966 trimming Methods 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Abstract
Description
本発明は、缶用鋼板およびその製造方法に関する。 The present invention relates to a steel sheet for cans and a method for manufacturing the same.
特許文献１～２には、「鋼板の表面に、前記鋼板側から順に、金属クロム層およびクロム水和酸化物層」を有し、更に、金属クロム層が「粒状突起」を有する缶用鋼板が開示されている。
近年、缶用鋼板に要求される特性のレベルが高まっている。とりわけ、製缶加工後の耐食性がより良好な缶用鋼板が求められている。
そこで、本発明は、耐食性に優れる缶用鋼板およびその製造方法を提供することを目的とする。
In recent years, the level of characteristics required for steel sheets for cans has been increasing. In particular, there is a demand for steel sheets for cans having better corrosion resistance after can manufacturing.
Therefore, an object of the present invention is to provide a steel sheet for cans having excellent corrosion resistance and a method for producing the same.
本発明者らが鋭意検討した結果、下記構成を採用することにより、上記目的が達成されることを見出し、本発明を完成させた。 As a result of diligent studies by the present inventors, it was found that the above object can be achieved by adopting the following configuration, and the present invention has been completed.
すなわち、本発明は、以下の［１］～［７］を提供する。
［１］鋼板の表面に、上記鋼板側から順に、金属クロム層およびクロム水和酸化物層を有し、上記金属クロム層の付着量が、５０～２００ｍｇ／ｍ２であり、上記クロム水和酸化物層のクロム換算の付着量が、１５ｍｇ／ｍ２以上であり、上記金属クロム層は、平板状の基部と、上記基部上に設けられた粒状突起と、を含み、上記粒状突起の最大粒径が、１００ｎｍ以下であり、上記粒状突起の個数密度が、１０個／μｍ２未満である、缶用鋼板。
［２］上記クロム水和酸化物層のクロム換算の付着量が、３０ｍｇ／ｍ２超である、上記［１］に記載の缶用鋼板。
［３］上記クロム水和酸化物層のクロム換算の付着量が、３２ｍｇ／ｍ２以上である、上記［１］または［２］に記載の缶用鋼板。
［４］上記［１］～［３］のいずれかに記載の缶用鋼板を製造する方法であって、鋼板に対して、六価クロム化合物およびフッ素含有化合物を含有する水溶液を用いて、陰極電解処理Ｃ１、陽極電解処理Ａ１および陰極電解処理Ｃ２を、この順に施し、上記陽極電解処理Ａ１の電流密度が、１０．０Ａ／ｄｍ２以上であり、上記陽極電解処理Ａ１の電気量密度が、５．０Ｃ／ｄｍ２以上である、缶用鋼板の製造方法。
［５］上記水溶液におけるＣｒ量が、０．５０ｍｏｌ／Ｌ以上であり、上記水溶液におけるＦ量が、０．１０ｍｏｌ／Ｌ超である、上記［４］に記載の缶用鋼板の製造方法。
［６］上記陰極電解処理Ｃ２の電流密度が、２０．０Ａ／ｄｍ２以上であり、上記陰極電解処理Ｃ２の電気量密度が、５．０Ｃ／ｄｍ２以上である、上記［４］または［５］に記載の缶用鋼板の製造方法。
［７］上記フッ素含有化合物が、上記水溶液中でフッ素イオンを遊離する化合物である、上記［４］～［６］のいずれかに記載の缶用鋼板の製造方法。
That is, the present invention provides the following [1] to [7].
[1] The surface of the steel plate has a metallic chromium layer and a chromium hydrated oxide layer in this order from the steel plate side, and the amount of the metallic chromium layer adhered is 50 to 200 mg / m 2 , and the chromium hydration. The adhesion amount of the oxide layer in terms of chromium is 15 mg / m 2 or more, and the metal chromium layer includes a flat plate-shaped base and granular protrusions provided on the base, and is the maximum of the granular protrusions. A steel plate for cans having a particle size of 100 nm or less and a number density of the granular protrusions of less than 10 pieces / μm 2 .
[2] The steel sheet for cans according to the above [1], wherein the adhesion amount of the chromium hydrated oxide layer in terms of chromium is more than 30 mg / m 2 .
[3] The steel sheet for cans according to the above [1] or [2], wherein the adhesion amount of the chromium hydrated oxide layer in terms of chromium is 32 mg / m 2 or more.
[4] The method for producing a steel plate for cans according to any one of the above [1] to [3], wherein an aqueous solution containing a hexavalent chromium compound and a fluorine-containing compound is used for the steel plate as a cathode. Electrolysis treatment C1, anodic electrolysis treatment A1 and cathode electrolysis treatment C2 are performed in this order. A method for manufacturing a steel plate for a can, which is 5.0 C / dm 2 or more.
[5] The method for producing a steel sheet for cans according to the above [4], wherein the amount of Cr in the aqueous solution is 0.50 mol / L or more and the amount of F in the aqueous solution is more than 0.10 mol / L.
[6] The current density of the cathode electrolytic treatment C2 is 20.0 A / dm 2 or more, and the electric quantity density of the cathode electrolytic treatment C2 is 5.0 C / dm 2 or more, the above [4] or [ 5] The method for manufacturing a steel sheet for a can.
[7] The method for producing a steel sheet for cans according to any one of [4] to [6] above, wherein the fluorine-containing compound is a compound that liberates fluorine ions in the aqueous solution.
本発明によれば、耐食性に優れる缶用鋼板およびその製造方法を提供できる。 According to the present invention, it is possible to provide a steel sheet for cans having excellent corrosion resistance and a method for producing the same.
［缶用鋼板］
図１は、缶用鋼板の一例を模式的に示す断面図である。
図１に示すように、鋼板２を有する。缶用鋼板１は、更に、鋼板２の表面に、鋼板２側から順に、金属クロム層３およびクロム水和酸化物層４を有する。
金属クロム層３は、鋼板２を覆う平板状の基部３ａと、基部３ａ上に設けられた粒状突起３ｂとを含む。クロム水和酸化物層４は、粒状突起３ｂの形状に追従するように、金属クロム層３上に配置される。
[Steel sheet for cans]
FIG. 1 is a cross-sectional view schematically showing an example of a steel plate for a can.
As shown in FIG. 1, it has a
The
以下、缶用鋼板の各構成について、より詳細に説明する。 Hereinafter, each configuration of the steel plate for cans will be described in more detail.
〈鋼板〉
鋼板の種類は特に限定されない。通常、容器材料として使用される鋼板（例えば、低炭素鋼板、極低炭素鋼板）を使用できる。鋼板の製造方法、材質なども特に限定されない。通常の鋼片製造工程から熱間圧延、酸洗、冷間圧延、焼鈍、調質圧延等の工程を経て製造される。
<Steel plate>
The type of steel sheet is not particularly limited. Usually, a steel plate used as a container material (for example, a low carbon steel plate or an extremely low carbon steel plate) can be used. The manufacturing method and material of the steel sheet are not particularly limited. It is manufactured through processes such as hot rolling, pickling, cold rolling, annealing, and temper rolling from the normal steel piece manufacturing process.
〈金属クロム層〉
上述した鋼板の表面には、金属クロム層が配置される。金属クロムは、鋼板の表面露出を抑えて耐食性を向上させる。
<Metallic chrome layer>
A metal chromium layer is arranged on the surface of the steel sheet described above. Metallic chromium suppresses surface exposure of the steel sheet and improves corrosion resistance.
《付着量》
缶用鋼板の耐食性が優れるという理由から、金属クロム層の付着量は、５０ｍｇ／ｍ２以上であり、６０ｍｇ／ｍ２以上が好ましく、７０ｍｇ／ｍ２以上がより好ましい。付着量は、鋼板の片面当たりの付着量である（以下、同様）。
<< Adhesion amount >>
The amount of the metal chromium layer adhered is 50 mg / m 2 or more, preferably 60 mg / m 2 or more, and more preferably 70 mg / m 2 or more because the corrosion resistance of the steel sheet for cans is excellent. The adhesion amount is the adhesion amount per one side of the steel sheet (hereinafter, the same applies).
ところで、缶用鋼板は、その表面が塗料やフィルムなどの有機樹脂で被覆された後、製缶加工される場合がある。
金属クロム量が多すぎると、有機樹脂との密着性（以下、単に「密着性」ともいう）が、製缶加工後に不十分となる場合がある。
缶用鋼板の製缶加工後の密着性が優れるという理由から、金属クロム層の付着量は、２００ｍｇ／ｍ２以下であり、１８０ｍｇ／ｍ２以下が好ましく、１６０ｍｇ／ｍ２以下がより好ましく、１３４ｍｇ／ｍ２以下が更に好ましい。
By the way, the surface of a steel sheet for cans may be coated with an organic resin such as a paint or a film and then processed into a can.
If the amount of metallic chromium is too large, the adhesion to the organic resin (hereinafter, also simply referred to as “adhesion”) may be insufficient after the can making process.
The amount of the metal chromium layer adhered is 200 mg / m 2 or less, preferably 180 mg / m 2 or less, more preferably 160 mg / m 2 or less, because the adhesiveness of the steel sheet for cans after can manufacturing is excellent. It is more preferably 134 mg / m 2 or less.
（付着量の測定方法）
金属クロム層の付着量、および、後述するクロム水和酸化物層のクロム換算の付着量は、次のようにして測定する。
まず、金属クロム層およびクロム水和酸化物層を形成させた缶用鋼板について、蛍光Ｘ線装置を用いて、クロム量（全クロム量）を測定する。次いで、缶用鋼板を９０℃の７．５Ｎ－ＮａＯＨ中に１０分間浸漬させるアルカリ処理を行なってから、再び、蛍光Ｘ線装置を用いて、クロム量（アルカリ処理後クロム量）を測定する。アルカリ処理後クロム量を、金属クロム層の付着量とする。
次に、（アルカリ可溶性クロム量）＝（全クロム量）－（アルカリ処理後クロム量）を計算し、アルカリ可溶性クロム量を、クロム水和酸化物層のクロム換算の付着量とする。
(Measuring method of adhesion amount)
The amount of adhesion of the metallic chromium layer and the amount of adhesion of the chromium hydrated oxide layer described later in terms of chromium are measured as follows.
First, the amount of chromium (total amount of chromium) is measured for a steel sheet for cans on which a metallic chromium layer and a chromium hydrated oxide layer are formed, using a fluorescent X-ray apparatus. Next, the steel sheet for cans is subjected to an alkali treatment by immersing it in 7.5 N-NaOH at 90 ° C. for 10 minutes, and then the amount of chromium (the amount of chromium after the alkali treatment) is measured again using a fluorescent X-ray apparatus. The amount of chromium after the alkali treatment is defined as the amount of adhesion of the metallic chromium layer.
Next, (alkali-soluble chromium amount) = (total chromium amount)-(chromium amount after alkali treatment) is calculated, and the alkali-soluble chromium amount is used as the chromium-equivalent adhesion amount of the chromium hydrated oxide layer.
このような金属クロム層は、平板状の基部と、基部上に設けられた粒状突起と、を含む。次に、金属クロム層が含むこれらの各部について、詳細に説明する。 Such a metallic chromium layer includes a flat plate-shaped base and granular protrusions provided on the base. Next, each of these parts included in the metallic chromium layer will be described in detail.
《基部》
金属クロム層の基部は、主に、鋼板の表面を被覆し、耐食性を向上させる。
金属クロム層の基部は、ハンドリング時に不可避的に缶用鋼板どうしが接触した際に、表層に設けられた粒状突起が基部を破壊して鋼板が露出しないように、充分な厚みを確保していることが好ましい。
缶用鋼板の耐食性が優れるという理由から、金属クロム層の基部の付着量は、３０ｍｇ／ｍ２以上が好ましく、４０ｍｇ／ｍ２以上がより好ましい。
"base"
The base of the metal chromium layer mainly covers the surface of the steel sheet to improve corrosion resistance.
The base of the metal chromium layer has a sufficient thickness so that when the steel plates for cans inevitably come into contact with each other during handling, the granular protrusions provided on the surface layer destroy the base and the steel plates are not exposed. Is preferable.
The amount of adhesion of the base of the metal chromium layer is preferably 30 mg / m 2 or more, and more preferably 40 mg / m 2 or more because the corrosion resistance of the steel sheet for cans is excellent.
《粒状突起》
金属クロム層の粒状突起は、上述した基部の表面に形成されており、例えば、缶用鋼板どうしの接触抵抗を低下させて溶接性を向上させる（粒状突起がクロム水和酸化物層を破壊して、溶接電流の通電点になり、接触抵抗が大幅に低下すると考えられる）。
《Granular protrusion》
The granular protrusions of the metal chromium layer are formed on the surface of the above-mentioned base, and for example, the contact resistance between the steel plates for cans is lowered to improve the weldability (the granular protrusions destroy the chromium hydrated oxide layer). Therefore, it becomes the current-carrying point of the welding current, and it is considered that the contact resistance is significantly reduced).
また、缶用鋼板を有機樹脂で被覆した場合において、粒状突起のアンカー効果によって、その有機樹脂との密着性が良好になる。 Further, when the steel sheet for cans is coated with the organic resin, the adhesion with the organic resin is improved by the anchor effect of the granular protrusions.
ところで、クロム水和酸化物層は、後述するように、耐食性などの特性を向上させる。
しかし、缶用鋼板を製缶加工する際に、粒状突起によって、クロム水和酸化物層が破壊される場合がある。この場合、製缶加工後の耐食性が不十分となり得る。
そこで、粒状突起の最大粒径を１００ｎｍ以下、かつ、粒状突起の個数密度を１０個／μｍ２未満にする。これにより、粒状突起によるクロム水和酸化物層の破壊が抑制され、製缶加工後の耐食性が優れる。
By the way, the chromium hydrated oxide layer improves properties such as corrosion resistance, as will be described later.
However, when the steel sheet for cans is processed into a can, the chromium hydrated oxide layer may be destroyed by the granular protrusions. In this case, the corrosion resistance after the can making process may be insufficient.
Therefore, the maximum particle size of the granular protrusions is 100 nm or less, and the number density of the granular protrusions is 10 pieces / μm 2 or less. As a result, the destruction of the chromium hydrated oxide layer due to the granular protrusions is suppressed, and the corrosion resistance after the can making process is excellent.
更に、これにより、缶用鋼板の表面外観が優れる。これは、粒状突起が小径化したり少なくなったりすることで、粒状突起による可視光の乱反射が抑制されて、色調が均一になるためと考えられる。 Further, this makes the surface appearance of the steel plate for cans excellent. It is considered that this is because the diameter of the granular protrusions is reduced or reduced, so that the diffused reflection of visible light by the granular protrusions is suppressed and the color tone becomes uniform.
（最大粒径）
粒状突起の最大粒径は、上述したように１００ｎｍ以下であり、缶用鋼板の表面外観がより優れるという理由から、６０ｎｍ以下が好ましく、４４ｎｍ以下がより好ましく、４０ｎｍ以下が更に好ましく、３５ｎｍ以下が特に好ましい。
下限は特に限定されず、粒状突起の最大粒径は、例えば、５ｎｍ以上である。
(Maximum particle size)
As described above, the maximum particle size of the granular protrusions is 100 nm or less, preferably 60 nm or less, more preferably 44 nm or less, further preferably 40 nm or less, and 35 nm or less because the surface appearance of the steel sheet for cans is more excellent. Especially preferable.
The lower limit is not particularly limited, and the maximum particle size of the granular protrusion is, for example, 5 nm or more.
（個数密度）
粒状突起の個数密度は、上述したように１０個／μｍ２未満であり、缶用鋼板の表面外観がより優れるという理由から、８個／μｍ２以下が好ましく、６個／μｍ２以下がより好ましい。
下限は特に限定されず、粒状突起の個数密度は、例えば、１個／μｍ２以上である。
(Number density)
As described above, the number density of the granular protrusions is less than 10 pieces / μm 2 , and 8 pieces / μm 2 or less is preferable, and 6 pieces / μm 2 or less is more preferable because the surface appearance of the steel sheet for cans is more excellent. preferable.
The lower limit is not particularly limited, and the number density of the granular protrusions is, for example, 1 piece / μm 2 or more.
（粒径および個数密度の測定方法）
金属クロム層の粒状突起の粒径および個数密度は、次のようにして求める。
まず、金属クロム層およびクロム水和酸化物層を形成させた缶用鋼板の表面に、カーボン蒸着を行ない、抽出レプリカ法によって観察用サンプルを作製する。その後、走査透過電子顕微鏡（ＴＥＭ）で２０，０００倍にて写真を撮影する。撮影した写真について、ソフトウェア（商品名：ＩｍａｇｅＪ）を用いて二値化して画像解析を行なうことで、粒状突起の占める面積から逆算し、真円換算として粒径および個数密度を求める。最大粒径は、５視野での最大の粒径とする。個数密度は、５視野の平均とする。
(Measuring method of particle size and number density)
The particle size and the number density of the granular protrusions of the metallic chromium layer are determined as follows.
First, carbon vapor deposition is performed on the surface of a steel sheet for cans on which a metallic chromium layer and a chromium hydrated oxide layer are formed, and an observation sample is prepared by an extraction replica method. Then, a photograph is taken with a scanning transmission electron microscope (TEM) at a magnification of 20,000. The photograph taken is binarized using software (trade name: ImageJ) and image analysis is performed to calculate back from the area occupied by the granular protrusions and obtain the particle size and the number density as a perfect circle conversion. The maximum particle size is the maximum particle size in five fields of view. The number density is the average of 5 fields of view.
〈クロム水和酸化物層〉
クロム水和酸化物は、鋼板の表面に金属クロムと同時に析出し、耐食性を向上させる。クロム水和酸化物は、例えば、クロム酸化物およびクロム水酸化物を含む。
<Chromium hydrated oxide layer>
Chromium hydrate precipitates on the surface of the steel sheet at the same time as metallic chromium, improving corrosion resistance. Chromium hydrated oxides include, for example, chromium oxides and chromium hydroxides.
《付着量》
クロム水和酸化物層は、その付着量が多いほど、製缶加工の際に粒状突起により破壊されにくく、良好な耐食性が維持されやすい。
缶用鋼板の製缶加工後の耐食性が優れるという理由から、クロム水和酸化物層のクロム換算の付着量は、１５ｍｇ／ｍ２以上であり、３０ｍｇ／ｍ２超が好ましく、３２ｍｇ／ｍ２以上がより好ましく、３５ｍｇ／ｍ２以上が更に好ましく、４０ｍｇ／ｍ２以上が特に好ましい。
<< Adhesion amount >>
The larger the adhered amount of the chromium hydrated oxide layer, the less likely it is to be destroyed by the granular protrusions during the can manufacturing process, and the better the corrosion resistance is easily maintained.
The adhesion amount of the chromium hydrated oxide layer in terms of chromium is 15 mg / m 2 or more, preferably more than 30 mg / m 2 and 32 mg / m 2 because the corrosion resistance of the steel sheet for cans after the can manufacturing process is excellent. The above is more preferable, 35 mg / m 2 or more is further preferable, and 40 mg / m 2 or more is particularly preferable.
なお、クロム水和酸化物層は、缶用鋼板を有機樹脂で被覆した場合において、その有機樹脂との密着性にも寄与する。
もっとも、クロム水和酸化物層の付着量が多すぎると、有機樹脂との密着性が製缶加工後に不十分となる場合がある。
このため、缶用鋼板の製缶加工後の密着性が優れるという理由から、クロム水和酸化物層のクロム換算の付着量は、８０ｍｇ／ｍ２以下が好ましく、７０ｍｇ／ｍ２以下がより好ましく、６０ｍｇ／ｍ２以下が更に好ましい。
The chromium hydrated oxide layer also contributes to the adhesion to the organic resin when the steel sheet for cans is coated with the organic resin.
However, if the amount of the chromium hydrated oxide layer adhered is too large, the adhesion to the organic resin may be insufficient after the can making process.
Therefore, the adhesion amount of the chromium hydrated oxide layer in terms of chromium is preferably 80 mg / m 2 or less, and more preferably 70 mg / m 2 or less, because the adhesion of the steel sheet for cans after the can manufacturing process is excellent. , 60 mg / m 2 or less is more preferable.
クロム水和酸化物層のクロム換算の付着量の測定方法は、上述したとおりである。 The method for measuring the amount of adhesion of the chromium hydrated oxide layer in terms of chromium is as described above.
［缶用鋼板の製造方法］
次に、上述した缶用鋼板を製造する方法を説明する。
概略的には、鋼板に対して、六価クロム化合物およびフッ素含有化合物を含有する水溶液を用いて、陰極電解処理Ｃ１、陽極電解処理Ａ１および陰極電解処理Ｃ２を、この順に施す。
[Manufacturing method of steel sheet for cans]
Next, a method for manufacturing the above-mentioned steel sheet for cans will be described.
Generally, a cathode electrolytic treatment C1, an anodic electrolytic treatment A1 and a cathode electrolytic treatment C2 are applied to a steel sheet in this order using an aqueous solution containing a hexavalent chromium compound and a fluorine-containing compound.
〈水溶液〉
水溶液は、少なくとも、六価クロム化合物およびフッ素含有化合物を含有する。
<Aqueous solution>
The aqueous solution contains at least a hexavalent chromium compound and a fluorine-containing compound.
六価クロム化合物としては、例えば、三酸化クロム（ＣｒＯ３）；二クロム酸カリウム（Ｋ２Ｃｒ２Ｏ7）などの二クロム酸塩；クロム酸カリウム（Ｋ２ＣｒＯ４）などのクロム酸塩；等が挙げられる。 Examples of the hexavalent chromium compound include chromium trioxide (CrO 3 ); dichromate such as potassium dichromate (K 2 Cr 2 O 7 ); and chromate such as potassium chromate (K 2 CrO 4 ). ; Etc. can be mentioned.
フッ素含有化合物としては、水溶液中で重フッ素イオンを遊離するケイフッ化水素酸の塩（ケイフッ化ナトリウム、ケイフッ化アンモニウムなど）よりも、水溶液中でフッ素イオンを遊離する化合物の方が好ましい。金属クロムの析出効率が良好であり、クロム水和酸化物層の膜厚が均一になりやすいからである。
水溶液中でフッ素イオンを遊離する化合物としては、例えば、フッ化水素酸（ＨＦ）、フッ化カリウム（ＫＦ）、フッ化ナトリウム（ＮａＦ）などが挙げられる。
As the fluorine-containing compound, a compound that liberates fluorine ions in an aqueous solution is preferable to a salt of hydrofluoric acid that liberates heavy fluorine ions in an aqueous solution (sodium silica fluoride, ammonium silica fluoride, etc.). This is because the precipitation efficiency of metallic chromium is good and the film thickness of the chromium hydrated oxide layer tends to be uniform.
Examples of the compound that liberates fluorine ions in an aqueous solution include hydrofluoric acid (HF), potassium fluoride (KF), and sodium fluoride (NaF).
水溶液におけるＣｒ量は、０．３０ｍｏｌ／Ｌ以上が好ましく、０．５０ｍｏｌ／Ｌ以上がより好ましく、０．７０ｍｏｌ／Ｌ以上が更に好ましい。
一方、水溶液におけるＣｒ量は、５．００ｍｏｌ／Ｌ以下が好ましく、３．００ｍｏｌ／Ｌ以下がより好ましい。
The amount of Cr in the aqueous solution is preferably 0.30 mol / L or more, more preferably 0.50 mol / L or more, and even more preferably 0.70 mol / L or more.
On the other hand, the amount of Cr in the aqueous solution is preferably 5.00 mol / L or less, more preferably 3.00 mol / L or less.
水溶液におけるＦ量は、０．１０ｍｏｌ／Ｌ超が好ましく、０．１５ｍｏｌ／Ｌ以上がより好ましい。
一方、水溶液におけるＦ量は、４．００ｍｏｌ／Ｌ以下が好ましく、２．００ｍｏｌ／Ｌ以下がより好ましい。
The amount of F in the aqueous solution is preferably more than 0.10 mol / L, more preferably 0.15 mol / L or more.
On the other hand, the amount of F in the aqueous solution is preferably 4.00 mol / L or less, more preferably 2.00 mol / L or less.
水溶液は、更に、硫酸を含有してもよい。硫酸は、その一部または全部が、硫酸ナトリウム、硫酸カルシウム、硫酸アンモニウムなどの硫酸塩であってもよい。
水溶液中のフッ素含有化合物および硫酸は、フッ化物イオン、硫酸イオンおよび硫酸水素イオンへと解離した状態で存在する。これらは、陰極電解処理および陽極電解処理において進行する、水溶液中に存在する六価クロムイオンの還元反応および酸化反応に関与する触媒として働く。
水溶液が硫酸を含有する場合、水溶液におけるＳＯ４
２－量は、０．０００１ｍｏｌ／Ｌ以上が好ましく、０．０００３ｍｏｌ／Ｌ以上がより好ましく、０．００１０ｍｏｌ／Ｌ以上が更に好ましい。
一方、このＳＯ４
２－量は、０．１０００ｍｏｌ／Ｌ以下が好ましく、０．０５００ｍｏｌ／Ｌ以下がより好ましい。
The aqueous solution may further contain sulfuric acid. Sulfuric acid may be a sulfate salt such as sodium sulfate, calcium sulfate, and ammonium sulfate in whole or in part.
The fluorine-containing compound and sulfuric acid in the aqueous solution exist in a state of being dissociated into fluoride ion, sulfate ion and hydrogen sulfate ion. These act as catalysts involved in the reduction reaction and oxidation reaction of hexavalent chromium ions present in the aqueous solution, which proceed in the cathode electrolysis treatment and the anodic electrolysis treatment.
When the aqueous solution contains sulfuric acid, the SO4-2 amount in the aqueous solution is preferably 0.0001 mol / L or more, more preferably 0.0003 mol / L or more, still more preferably 0.0010 mol / L or more.
On the other hand, the amount of SO 4-2 is preferably 0.1000 mol / L or less, more preferably 0.0500 mol / L or less.
陰極電解処理Ｃ１、陽極電解処理Ａ１、および、陰極電解処理Ｃ１においては、１種類の水溶液のみを用いてもよく、２種類以上の水溶液を併用してもよい。
水溶液の液温は、２０℃以上が好ましく、４０℃以上がより好ましい。一方、この液温は、８０℃以下が好ましく、６０℃以下がより好ましい。
In the cathode electrolysis treatment C1, the anode electrolysis treatment A1, and the cathode electrolysis treatment C1, only one kind of aqueous solution may be used, or two or more kinds of aqueous solutions may be used in combination.
The liquid temperature of the aqueous solution is preferably 20 ° C. or higher, more preferably 40 ° C. or higher. On the other hand, the liquid temperature is preferably 80 ° C. or lower, more preferably 60 ° C. or lower.
〈陰極電解処理Ｃ１〉
陰極電解処理Ｃ１は、金属クロムおよびクロム水和酸化物を析出させる。
このとき、適切な析出量とする観点から、陰極電解処理Ｃ１の電気量密度（電流密度と通電時間との積）は、３０．０Ｃ／ｄｍ２以上が好ましく、４５．０Ｃ／ｄｍ２以上がより好ましい。
一方、陰極電解処理Ｃ１の電気量密度は、７０．０Ｃ／ｄｍ２以下が好ましく、５５．０Ｃ／ｄｍ２以下がより好ましい。
陰極電解処理Ｃ１の電流密度（単位：Ａ／ｄｍ２）および通電時間（単位：ｓｅｃ．）は、上記の電気量密度から、適宜設定される。
<Cathode electrolysis treatment C1>
Cathode electrolysis treatment C1 precipitates metallic chromium and chromium hydrated oxide.
At this time, from the viewpoint of obtaining an appropriate precipitation amount, the electric quantity density (product of the current density and the energization time) of the cathode electrolysis treatment C1 is preferably 30.0 C / dm 2 or more, and 45.0 C / dm 2 or more. More preferred.
On the other hand, the electric energy density of the cathode electrolysis treatment C1 is preferably 70.0 C / dm 2 or less, and more preferably 55.0 C / dm 2 or less.
The current density (unit: A / dm 2 ) and energization time (unit: sec.) Of the cathode electrolysis treatment C1 are appropriately set from the above-mentioned electric quantity density.
〈陽極電解処理Ａ１〉
陽極電解処理Ａ１は、陰極電解処理Ｃ１で析出した金属クロムを溶解させて、陰極電解処理Ｃ２における金属クロム層の粒状突起の発生サイトを形成する。
このとき、陽極電解処理Ａ１において、電流密度を１０．０Ａ／ｄｍ２以上、電気量密度を５．０Ｃ／ｄｍ２以上にする。
これにより、金属クロムの溶解が強くなり、発生サイトが減少し、粒状突起の個数密度が減少したり、粒状突起が小径化したりする。
<Anode electrolysis treatment A1>
The anodic electrolysis treatment A1 dissolves the metallic chromium precipitated in the cathode electrolysis treatment C1 to form a site where granular protrusions of the metallic chromium layer are generated in the cathode electrolysis treatment C2.
At this time, in the anode electrolysis treatment A1, the current density is 10.0 A / dm 2 or more, and the electric energy density is 5.0 C / dm 2 or more.
As a result, the dissolution of metallic chromium becomes stronger, the number of generated sites decreases, the number density of the granular protrusions decreases, and the diameter of the granular protrusions becomes smaller.
ところで、陽極電解処理Ａ１では、クロム水和酸化物層も溶解する。
このとき、クロム水和酸化物層が不均一に溶解すると、続く陰極電解処理Ｃ２では、クロム水和酸化物層における局所的に溶解した部分において、優先的に金属クロムが析出して、粒状突起が形成される。この場合、粒状突起は、大径化したり、個数密度が増加したりしやすい。
しかしながら、陽極電解処理Ａ１の電流密度および電気量密度を上記範囲にすることで、クロム水和酸化物層の不均一な溶解が抑制される。これにより、粒状突起の大径化および個数密度の増加が抑制される。
更に、その結果、クロム水和酸化物層の付着量を、十分な量にすることができる。
By the way, in the anode electrolysis treatment A1, the chromium hydrated oxide layer is also dissolved.
At this time, when the chromium hydrated oxide layer is non-uniformly dissolved, in the subsequent cathode electrolysis treatment C2, metallic chromium is preferentially deposited in the locally dissolved portion of the chromium hydrated oxide layer, and granular protrusions are formed. Is formed. In this case, the granular protrusions tend to have a large diameter and an increase in the number density.
However, by setting the current density and the electric quantity density of the anode electrolysis treatment A1 within the above ranges, the non-uniform dissolution of the chromium hydrated oxide layer is suppressed. As a result, the increase in diameter and the number density of the granular protrusions are suppressed.
Further, as a result, the amount of the chromium hydrated oxide layer attached can be made sufficient.
陽極電解処理Ａ１の電流密度は、上述したように１０．０Ａ／ｄｍ２以上であり、２０．０Ａ／ｄｍ２以上が好ましく、３０．０Ａ／ｄｍ２以上がより好ましい。
上限は特に限定されず、陽極電解処理Ａ１の電流密度は、例えば、８０．０Ｃ／ｄｍ２以下であり、７０．０Ｃ／ｄｍ２以下が好ましい。
As described above, the current density of the anode electrolysis treatment A1 is 10.0 A / dm 2 or more, preferably 20.0 A / dm 2 or more, and more preferably 30.0 A / dm 2 or more.
The upper limit is not particularly limited, and the current density of the anode electrolysis treatment A1 is, for example, 80.0 C / dm 2 or less, preferably 70.0 C / dm 2 or less.
陽極電解処理Ａ１の電気量密度は、上述したように５．０Ｃ／ｄｍ２以上であり、１０．０Ｃ／ｄｍ２以上が好ましく、１５．０Ｃ／ｄｍ２以上がより好ましく、２０．０Ｃ／ｄｍ２以上が更に好ましい。
上限は特に限定されず、陽極電解処理Ａ１の電気量密度は、例えば、４０．０Ｃ／ｄｍ２以下であり、３５．０Ｃ／ｄｍ２以下が好ましい。
As described above, the electric energy density of the anode electrolysis treatment A1 is 5.0 C / dm 2 or more, preferably 10.0 C / dm 2 or more, more preferably 15.0 C / dm 2 or more, and 20.0 C / dm. 2 or more is more preferable.
The upper limit is not particularly limited, and the electric energy density of the anode electrolysis treatment A1 is, for example, 40.0 C / dm 2 or less, preferably 35.0 C / dm 2 or less.
陽極電解処理Ａ１の通電時間（単位：ｓｅｃ．）は、上記の電流密度および電気量密度から、適宜設定される。 The energization time (unit: sec.) Of the anode electrolysis treatment A1 is appropriately set from the above current density and electric quantity density.
〈陰極電解処理Ｃ２〉
上述したように、陰極電解処理は、金属クロムおよびクロム水和酸化物を析出させる。
特に、陰極電解処理Ｃ２は、上述した発生サイトを起点として、金属クロム層の粒状突起を生成させる。更に、陰極電解処理Ｃ２は、クロム水和酸化物層の付着量を制御する。
クロム析出反応と競合する水素発生反応を効果的に抑制し、金属クロム層およびクロム水和酸化物層を効率良く析出させるという理由から、陰極電解処理Ｃ２の電流密度は、２０．０Ａ／ｄｍ２以上が好ましく、３０．０Ａ／ｄｍ２以上がより好ましい。
一方、陰極電解処理Ｃ２の電流密度は、６０．０Ａ／ｄｍ２以下が好ましく、５０．０Ａ／ｄｍ２以下がより好ましい。
<Cathode electrolysis treatment C2>
As mentioned above, the cathode electrolysis treatment precipitates metallic chromium and chromium hydrated oxide.
In particular, the cathode electrolysis treatment C2 generates granular protrusions of the metal chromium layer starting from the above-mentioned generation site. Further, the cathode electrolysis treatment C2 controls the amount of adhesion of the chromium hydrated oxide layer.
The current density of the cathode electrolytic treatment C2 is 20.0 A / dm 2 because it effectively suppresses the hydrogen generation reaction that competes with the chromium precipitation reaction and efficiently precipitates the metallic chromium layer and the chromium hydrated oxide layer. The above is preferable, and 30.0 A / dm 2 or more is more preferable.
On the other hand, the current density of the cathode electrolysis treatment C2 is preferably 60.0 A / dm 2 or less, and more preferably 50.0 A / dm 2 or less.
同様の理由から、陰極電解処理Ｃ２の電気量密度は、５．０Ｃ／ｄｍ２以上が好ましく、７．０Ｃ／ｄｍ２以上がより好ましく、１０．０Ｃ／ｄｍ２以上が更に好ましい。
一方、陰極電解処理Ｃ２の電気量密度は、３０．０Ｃ／ｄｍ２以下が好ましく、２５．０Ｃ／ｄｍ２以下がより好ましく、２０．０Ｃ／ｄｍ２以下が更に好ましい。
For the same reason, the electric energy density of the cathode electrolysis treatment C2 is preferably 5.0 C / dm 2 or more, more preferably 7.0 C / dm 2 or more, and further preferably 10.0 C / dm 2 or more.
On the other hand, the electric energy density of the cathode electrolysis treatment C2 is preferably 30.0 C / dm 2 or less, more preferably 25.0 C / dm 2 or less, and further preferably 20.0 C / dm 2 or less.
陰極電解処理Ｃ２の通電時間（単位：ｓｅｃ．）は、上記の電流密度および電気量密度から、適宜設定される。 The energization time (unit: sec.) Of the cathode electrolysis treatment C2 is appropriately set from the above current density and electric quantity density.
陰極電解処理Ｃ１、陽極電解処理Ａ１および陰極電解処理Ｃ２は、それぞれ、連続電解処理でなくてもよい。すなわち、工業生産上、複数の電極に分けて電解することにより不可避的に無通電浸漬時間が存在する断続電解処理であってもよい。断続電解処理の場合、トータルの電気量密度が上記範囲内であることが好ましい。 The cathode electrolysis treatment C1, the anode electrolysis treatment A1 and the cathode electrolysis treatment C2 do not have to be continuous electrolysis treatments, respectively. That is, in industrial production, it may be an intermittent electrolysis treatment in which a non-energized immersion time is inevitably present by electrolyzing the electrodes separately. In the case of intermittent electrolysis treatment, it is preferable that the total electric quantity density is within the above range.
以下に、実施例を挙げて本発明を具体的に説明する。ただし、本発明は以下の実施例に限定されない。 Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples.
〈缶用鋼板の作製〉
０．２２ｍｍの板厚で製造した鋼板（調質度：Ｔ５ＣＡ）に対して、通常の脱脂および酸洗を施した。
次いで、この鋼板に対して、下記表１に示す水溶液のいずれかを流動セルでポンプにより１００ｍｐｍ相当で循環させ、鉛電極を使用し、下記表２に示す条件で電解処理（陰極電解処理Ｃ１、陽極電解処理Ａ１および陰極電解処理Ｃ２）を施した。電解処理を施さなかった場合は、下記表２に「－」を記載した。
こうして、缶用鋼板を作製した。作製後の缶用鋼板は、水洗し、ブロアを用いて室温で乾燥した。
<Making steel sheets for cans>
A steel sheet (furnishing degree: T5CA) manufactured with a plate thickness of 0.22 mm was subjected to normal degreasing and pickling.
Next, one of the aqueous solutions shown in Table 1 below was circulated to this steel plate at a pump of 100 mpm in a flow cell, and a lead electrode was used for electrolysis treatment (cathode electrolysis treatment C1,) under the conditions shown in Table 2 below. Anode electrolysis treatment A1 and cathode electrolysis treatment C2) were performed. When the electrolytic treatment was not performed, "-" is shown in Table 2 below.
In this way, a steel plate for cans was produced. The prepared steel sheet for cans was washed with water and dried at room temperature using a blower.
〈付着量ならびに粒状突起の最大粒径および個数密度〉
作製した缶用鋼板について、金属クロム層の付着量、および、クロム水和酸化物層のクロム換算の付着量（下記表３では単に「付着量」と表記）を測定した。
また、作製した缶用鋼板の金属クロム層について、粒状突起の最大粒径および個数密度を測定した。
測定方法は、いずれも上述したとおりである。結果を下記表３に示す。粒状突起が観察されなかった場合は、下記表３に「－」を記載した。
<Adhesion amount and maximum particle size and number density of granular protrusions>
With respect to the produced steel sheet for cans, the amount of adhesion of the metallic chromium layer and the amount of adhesion of the chromium hydrated oxide layer in terms of chromium (indicated simply as "adhesion amount" in Table 3 below) were measured.
In addition, the maximum particle size and the number density of the granular protrusions were measured for the metallic chromium layer of the produced steel sheet for cans.
The measuring methods are all as described above. The results are shown in Table 3 below. When no granular protrusions were observed, "-" is shown in Table 3 below.
〈評価〉
作製した缶用鋼板について、以下の評価を行なった。評価結果は下記表３に示す。
<evaluation>
The following evaluations were made on the produced steel sheets for cans. The evaluation results are shown in Table 3 below.
《表面外観》
作製した缶用鋼板について、旧ＪＩＳ Ｚ ８７３０（１９８０）において規定されるハンター式色差測定に基づいて、Ｌ値を測定した。缶用鋼板ごとに、任意の１０部位でＬ値を測定し、その平均値および標準偏差値σを求め、下記基準に従い評価した。実用上、「◎」または「○」であれば、表面外観に優れると評価できる。
◎：７０≦Ｌ値の平均値、σ≦１
○：６７≦Ｌ値の平均値＜７０、１＜σ≦３
×：Ｌ値の平均値＜６７、３＜σ
《Surface appearance》
The L value of the produced steel sheet for cans was measured based on the Hunter-type color difference measurement specified in the old JIS Z 8730 (1980). The L value was measured at any 10 sites for each steel sheet for cans, and the average value and standard deviation value σ were obtained and evaluated according to the following criteria. Practically, if it is "◎" or "○", it can be evaluated that the surface appearance is excellent.
⊚: mean value of 70 ≦ L value, σ ≦ 1
◯: Average value of 67 ≦ L values <70, 1 <σ ≦ 3
×: Mean value of L value <67, 3 <σ
《製缶加工後の特性》
作製した缶用鋼板を有機樹脂（延伸フィルム）で被覆してから、金属缶（シームレス缶）を作製し、耐食性および密着性を評価した。具体的には、以下のとおりである。
<< Characteristics after can making >>
After coating the produced steel sheet for cans with an organic resin (stretched film), a metal can (seamless can) was produced, and the corrosion resistance and adhesion were evaluated. Specifically, it is as follows.
（有機樹脂被覆鋼板の作製）
作製した缶用鋼板の一方の片面（金属缶の内面となる面）上に、厚さ１９μｍの延伸フィルム１を、他方の片面（金属缶の外面となる面）上に、厚さ１３μｍの延伸フィルム２を、それぞれ、ラミネートロールを介して熱圧着させた。
延伸フィルム１は、ポリエチレンテレフタレートおよびイソフタレートの共重合組成を有し、１１モル％のイソフタル酸成分を含有する、延伸フィルムである。
延伸フィルム２は、ポリエチレンテレフタレートおよびイソフタレートの共重合組成を有し、１２モル％のイソフタル酸成分を含有する、延伸フィルムである。延伸フィルム２は、更に、酸化チタンを含有することにより、ホワイトに着色している。
熱圧着後、直ちに水冷することにより、延伸フィルムに適度な配向状態が残るように留意しながら、有機樹脂被覆鋼板を得た。得られた有機樹脂被覆鋼板は、後述する金属缶（シームレス缶）の作製に使用した。
(Manufacturing of organic resin coated steel sheet)
A stretched film 1 having a thickness of 19 μm is stretched on one side (the inner surface of the metal can) of the produced steel sheet for cans, and a stretched film 1 having a thickness of 13 μm is stretched on the other side (the outer surface of the metal can). Each of the
The stretched film 1 is a stretched film having a copolymerization composition of polyethylene terephthalate and isophthalate and containing 11 mol% of an isophthalic acid component.
The stretched
Immediately after thermocompression bonding, water cooling was performed to obtain an organic resin-coated steel sheet while paying attention so that an appropriate orientation state remained on the stretched film. The obtained organic resin-coated steel sheet was used for producing a metal can (seamless can) described later.
（金属缶の作製）
得られた有機樹脂被覆鋼板を、その両面にパラフィンワックスを塗布してから、直径１４３ｍｍの円形に打ち抜いた。円形に打ち抜かれた有機樹脂被覆鋼板を用いて、定法に従い、径９１ｍｍ、高さ３６ｍｍの絞りカップを作製した。
次いで、作製した絞りカップを、同時絞りしごき加工を２回繰り返すことによって、径が小さく高さの大きいカップに成形した。得られたカップの諸特性を、以下に示す。
カップ径：５２．０ｍｍ
カップ高さ：１１１．７ｍｍ
元板厚に対する板厚減少率（缶側壁部）：３０％
得られたカップをドーミング成形した後、延伸フィルムの歪みを除去するために、２２０℃で６０秒間の熱処理を実施した。続いて、カップの開口端をトリミング加工してから、曲面印刷した。その後、直径が５０．８ｍｍとなるようにネックイン加工し、更に、フランジ加工をした。こうして、２００ｍＬ用の金属缶（シームレス缶）を得た。
(Making metal cans)
The obtained organic resin-coated steel sheet was coated with paraffin wax on both sides thereof, and then punched into a circle having a diameter of 143 mm. Using an organic resin-coated steel plate punched out in a circle, a drawn cup having a diameter of 91 mm and a height of 36 mm was produced according to a conventional method.
Next, the produced drawing cup was formed into a cup having a small diameter and a large height by repeating the simultaneous drawing and ironing process twice. The characteristics of the obtained cup are shown below.
Cup diameter: 52.0 mm
Cup height: 111.7 mm
Plate thickness reduction rate with respect to the original plate thickness (can side wall): 30%
After doming molding of the obtained cup, heat treatment was performed at 220 ° C. for 60 seconds in order to remove the strain of the stretched film. Subsequently, after trimming the open end of the cup, curved surface printing was performed. Then, neck-in processing was performed so that the diameter was 50.8 mm, and further flange processing was performed. In this way, a metal can (seamless can) for 200 mL was obtained.
（耐食性）
得られたシームレス缶の缶側壁部を、試験片として切り出した。試験片の端部を、テープで被覆した。その後、試験片における缶下部から５０ｍｍの部分に、カッターを用いて、長さ４ｃｍのクロスカットを入れた。クロスカットを入れた試験片を、市販のコーヒー（商品名：Ｂｌｅｎｄｙ・ボトルコーヒー低糖、味の素ゼネラルフーズ社製）に浸漬し、３７℃に保持した状態で、４週間経過させた。その後、クロスカット部からの変色の広がり（片側あたり）を測定し、下記基準に従い評価した。実用上、「◎◎」、「◎」または「○」であれば、耐食性に優れると評価できる。
◎◎：０．３ｍｍ未満
◎：０．３ｍｍ以上０．５ｍｍ未満
○：０．５ｍｍ以上１ｍｍ未満
△：１ｍｍ以上２ｍｍ未満
×：２ｍｍ以上
(Corrosion resistance)
The side wall portion of the obtained seamless can was cut out as a test piece. The edges of the test piece were covered with tape. Then, a cross cut having a length of 4 cm was placed in a portion of the test piece 50 mm from the lower part of the can using a cutter. The test piece containing the cross cut was immersed in commercially available coffee (trade name: Blendy, bottle coffee low sugar, manufactured by Ajinomoto General Foods Co., Ltd.) and kept at 37 ° C. for 4 weeks. Then, the spread of discoloration (per one side) from the cross-cut portion was measured and evaluated according to the following criteria. Practically, if it is "◎◎", "◎" or "○", it can be evaluated as having excellent corrosion resistance.
◎ ◎: Less than 0.3 mm ◎: 0.3 mm or more and less than 0.5 mm ○: 0.5 mm or more and less than 1 mm △: 1 mm or more and less than 2 mm ×: 2 mm or more
（密着性）
得られたシームレス缶の缶側壁部の外面（缶上部から１５ｍｍの部分）に、直線状の切れ目を入れた。その後、引張試験機を用いて、延伸フィルムを缶高さ方向（１８０度方向）に引き剥がし、その際の最大引張強さを測定し、下記基準に従い評価した。実用上、「◎」または「○」であれば、密着性に優れると評価できる。
◎：３．０Ｎ／１５ｍｍ以上
○：０．５Ｎ／１５ｍｍ以上３．０Ｎ／１５ｍｍ未満
×：０．５Ｎ／１５ｍｍ未満
(Adhesion)
A linear cut was made in the outer surface (a portion 15 mm from the upper part of the can) of the side wall portion of the obtained seamless can. Then, the stretched film was peeled off in the can height direction (180 degree direction) using a tensile tester, and the maximum tensile strength at that time was measured and evaluated according to the following criteria. Practically, if it is "◎" or "○", it can be evaluated as having excellent adhesion.
⊚: 3.0N / 15mm or more ○: 0.5N / 15mm or more and less than 3.0N / 15mm ×: 0.5N / less than 15mm
〈評価結果まとめ〉
上記表３に示す結果は、以下のとおりであった。
<Summary of evaluation results>
The results shown in Table 3 above were as follows.
《比較例１～４の説明》
クロム水和酸化物層の付着量が１５ｍｇ／ｍ２未満である比較例１は、製缶加工後の耐食性が不十分であった。
クロム水和酸化物層の付着量が１５ｍｇ／ｍ２未満であり、粒状突起の最大粒径が１００ｎｍ超であり、かつ、粒状突起の個数密度が１０個／μｍ２以上である比較例２～４は、製缶加工後の耐食性が不十分であった。
<< Explanation of Comparative Examples 1 to 4 >>
In Comparative Example 1 in which the amount of the chromium hydrated oxide layer adhered was less than 15 mg / m 2 , the corrosion resistance after the can-making process was insufficient.
Comparative Examples 2 to 2 in which the adhesion amount of the chromium hydrated oxide layer is less than 15 mg / m 2 , the maximum particle size of the granular protrusions is more than 100 nm, and the number density of the granular protrusions is 10 pieces / μm 2 or more. No. 4 had insufficient corrosion resistance after can making.
《実施例１～２０の説明》
クロム水和酸化物層の付着量が１５ｍｇ／ｍ２以上であり、粒状突起の最大粒径が１００ｎｍ以下であり、かつ、粒状突起の個数密度が１０個／μｍ２未満である実施例１～２０の缶用鋼板は、比較例１～４と比較して、製缶加工後の耐食性に優れていた。
更に、実施例１～２０の缶用鋼板は、表面外観に優れ、かつ、製缶加工後の密着性も良好であった。
<< Explanation of Examples 1 to 20 >>
Examples 1 to 1 to Example 1 in which the adhesion amount of the chromium hydrated oxide layer is 15 mg / m 2 or more, the maximum particle size of the granular protrusions is 100 nm or less, and the number density of the granular protrusions is 10 pieces / μm 2 or less. The steel sheets for cans of 20 were excellent in corrosion resistance after the can-making process as compared with Comparative Examples 1 to 4.
Further, the steel sheets for cans of Examples 1 to 20 had excellent surface appearance and good adhesion after can manufacturing.
金属クロム層の付着量が１３４ｍｇ／ｍ２以下である各実施例（実施例８を除く）は、これを満たさない実施例９、１５および１８よりも製缶加工後の密着性がより良好であった。 Each example (excluding Example 8) having an adhesion amount of the metallic chromium layer of 134 mg / m 2 or less has better adhesion after can making than Examples 9, 15 and 18 which do not satisfy this. there were.
クロム水和酸化物層の付着量が３２ｍｇ／ｍ２以上である実施例６～８、１１、１４、１７および２０は、これを満たさない各実施例と比較して、製缶加工後の耐食性がより良好であった。
このうち、実施例７～８は、製缶加工後の耐食性が更に良好であった。
ただし、製缶加工後の密着性については、実施例８よりも、クロム水和酸化物層の付着量が少ない実施例７の方が良好であった。
Examples 6 to 8, 11, 14, 17 and 20 in which the adhesion amount of the chromium hydrated oxide layer is 32 mg / m 2 or more have corrosion resistance after can making as compared with each example which does not satisfy this. Was better.
Of these, Examples 7 to 8 had even better corrosion resistance after can making.
However, the adhesion after the can-making process was better in Example 7 in which the amount of the chromium hydrated oxide layer adhered was smaller than in Example 8.
粒状突起の最大粒径が４４ｎｍ以下であり、かつ、粒状突起の個数密度が６個／μｍ２以下である各実施例は、これらのいずれか一方または両方を満たさない実施例４、９、１２、１５、１８および１９と比較して、表面外観がより良好であった。 Examples 4, 9, and 12 in which the maximum particle size of the granular protrusions is 44 nm or less and the number density of the granular protrusions is 6 pieces / μm 2 or less do not satisfy either or both of them. , 15, 18 and 19, the surface appearance was better.
１：缶用鋼板
２：鋼板
３：金属クロム層
３ａ：基部
３ｂ：粒状突起
４：クロム水和酸化物層
1: Steel plate for cans 2: Steel plate 3:
Claims (7)
前記金属クロム層の付着量が、５０～２００ｍｇ／ｍ２であり、
前記クロム水和酸化物層のクロム換算の付着量が、１５ｍｇ／ｍ２以上であり、
前記金属クロム層は、平板状の基部と、前記基部上に設けられた粒状突起と、を含み、
前記粒状突起の最大粒径が、１００ｎｍ以下であり、
前記粒状突起の個数密度が、１０個／μｍ２未満である、缶用鋼板。 A metal chromium layer and a chromium hydrated oxide layer are provided on the surface of the steel sheet in this order from the steel sheet side.
The amount of the metal chromium layer adhered is 50 to 200 mg / m 2 .
The adhered amount of the chromium hydrated oxide layer in terms of chromium is 15 mg / m 2 or more.
The metallic chromium layer includes a flat plate-shaped base and granular protrusions provided on the base.
The maximum particle size of the granular protrusion is 100 nm or less, and the particle size is 100 nm or less.
A steel sheet for cans in which the number density of the granular protrusions is less than 10 pieces / μm 2 .
鋼板に対して、六価クロム化合物およびフッ素含有化合物を含有する水溶液を用いて、陰極電解処理Ｃ１、陽極電解処理Ａ１および陰極電解処理Ｃ２を、この順に施し、
前記陽極電解処理Ａ１の電流密度が、１０．０Ａ／ｄｍ２以上であり、
前記陽極電解処理Ａ１の電気量密度が、５．０Ｃ／ｄｍ２以上である、缶用鋼板の製造方法。 The method for manufacturing a steel sheet for cans according to any one of claims 1 to 3.
Cathodic electrolysis treatment C1, anodic electrolysis treatment A1 and cathode electrolysis treatment C2 are applied to the steel sheet in this order using an aqueous solution containing a hexavalent chromium compound and a fluorine-containing compound.
The current density of the anode electrolysis treatment A1 is 10.0 A / dm 2 or more, and the current density is 10.0 A / dm 2.
A method for manufacturing a steel sheet for cans, wherein the electric energy density of the anode electrolysis treatment A1 is 5.0 C / dm 2 or more.
前記水溶液におけるＦ量が、０．１０ｍｏｌ／Ｌ超である、請求項４に記載の缶用鋼板の製造方法。 The amount of Cr in the aqueous solution is 0.50 mol / L or more, and the amount of Cr is 0.50 mol / L or more.
The method for producing a steel sheet for cans according to claim 4, wherein the amount of F in the aqueous solution is more than 0.10 mol / L.
前記陰極電解処理Ｃ２の電気量密度が、５．０Ｃ／ｄｍ２以上である、請求項４または５に記載の缶用鋼板の製造方法。 The current density of the cathode electrolysis treatment C2 is 20.0 A / dm 2 or more, and the current density is 20.0 A / dm 2.
The method for producing a steel sheet for cans according to claim 4 or 5, wherein the electric energy density of the cathode electrolysis treatment C2 is 5.0 C / dm 2 or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020205743A JP7384151B2 (en) | 2020-12-11 | 2020-12-11 | Steel plate for cans and its manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020205743A JP7384151B2 (en) | 2020-12-11 | 2020-12-11 | Steel plate for cans and its manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2022092815A true JP2022092815A (en) | 2022-06-23 |
| JP7384151B2 JP7384151B2 (en) | 2023-11-21 |
Family
ID=82069067
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2020205743A Active JP7384151B2 (en) | 2020-12-11 | 2020-12-11 | Steel plate for cans and its manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP7384151B2 (en) |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3348672B2 (en) | 1999-02-26 | 2002-11-20 | 日本鋼管株式会社 | Laminated steel plate for non-polishing welded general cans |
| CA3007983C (en) | 2015-12-11 | 2020-04-28 | Jfe Steel Corporation | Steel sheet for cans and production method for steel sheet for cans |
| CN112639172B (en) | 2018-08-29 | 2023-11-07 | 杰富意钢铁株式会社 | Steel sheet for cans and method for producing same |
-
2020
- 2020-12-11 JP JP2020205743A patent/JP7384151B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP7384151B2 (en) | 2023-11-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP7067543B2 (en) | Steel sheet for cans and its manufacturing method | |
| JP6648835B2 (en) | Steel plate for can and method of manufacturing the same | |
| JP6493519B2 (en) | Steel plate for can and manufacturing method thereof | |
| JP6601574B2 (en) | Steel plate for can and manufacturing method thereof | |
| JP6493520B2 (en) | Steel plate for can and manufacturing method thereof | |
| JP7056594B2 (en) | Steel sheet for cans and its manufacturing method | |
| JP7409337B2 (en) | Steel plate for cans and its manufacturing method | |
| JP7024807B2 (en) | Steel sheet for cans and its manufacturing method | |
| JP7384151B2 (en) | Steel plate for cans and its manufacturing method | |
| TWI730341B (en) | Steel plate for tank and manufacturing method thereof | |
| WO2023112467A1 (en) | Steel sheet for cans and method for producing same | |
| JP7239014B2 (en) | Steel plate for can and manufacturing method thereof | |
| JP7023418B2 (en) | Roughened nickel plated plate | |
| JP7239087B1 (en) | Steel plate for can and manufacturing method thereof | |
| WO2023127236A1 (en) | Can steel sheet and method for producing same | |
| JP6164206B2 (en) | Steel plate for container and method for producing the same | |
| KR20230121871A (en) | Steel sheet for cans and its manufacturing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20220725 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20230526 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20230606 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20230726 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20231010 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20231023 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 7384151 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |