JP2950199B2 - Electrogalvanized steel sheet and electrogalvanized steel sheet having excellent wood grain resistance, and methods for producing them - Google Patents
Electrogalvanized steel sheet and electrogalvanized steel sheet having excellent wood grain resistance, and methods for producing themInfo
- Publication number
- JP2950199B2 JP2950199B2 JP7144989A JP14498995A JP2950199B2 JP 2950199 B2 JP2950199 B2 JP 2950199B2 JP 7144989 A JP7144989 A JP 7144989A JP 14498995 A JP14498995 A JP 14498995A JP 2950199 B2 JP2950199 B2 JP 2950199B2
- Authority
- JP
- Japan
- Prior art keywords
- steel sheet
- steel
- less
- grain
- electrogalvanized
- 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 - Lifetime
Links
- 229910000831 Steel Inorganic materials 0.000 title claims description 151
- 239000010959 steel Substances 0.000 title claims description 151
- 238000000034 method Methods 0.000 title claims description 20
- 239000002023 wood Substances 0.000 title description 23
- 238000007747 plating Methods 0.000 claims description 59
- 238000000605 extraction Methods 0.000 claims description 37
- 238000005098 hot rolling Methods 0.000 claims description 19
- 239000002344 surface layer Substances 0.000 claims description 14
- 238000004519 manufacturing process Methods 0.000 claims description 13
- 239000010410 layer Substances 0.000 claims description 12
- 239000000463 material Substances 0.000 claims description 12
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 claims description 8
- 239000011347 resin Substances 0.000 claims description 8
- 229920005989 resin Polymers 0.000 claims description 8
- 229910001335 Galvanized steel Inorganic materials 0.000 claims description 7
- 239000008397 galvanized steel Substances 0.000 claims description 7
- 229910052748 manganese Inorganic materials 0.000 claims description 7
- 229910052710 silicon Inorganic materials 0.000 claims description 6
- 229910052757 nitrogen Inorganic materials 0.000 claims description 5
- 229910052698 phosphorus Inorganic materials 0.000 claims description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 77
- 230000007547 defect Effects 0.000 description 28
- 238000011282 treatment Methods 0.000 description 27
- 238000000137 annealing Methods 0.000 description 19
- 238000005096 rolling process Methods 0.000 description 16
- 238000010438 heat treatment Methods 0.000 description 10
- 239000010960 cold rolled steel Substances 0.000 description 9
- 230000007423 decrease Effects 0.000 description 9
- 239000011248 coating agent Substances 0.000 description 8
- 238000000576 coating method Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 8
- 238000005554 pickling Methods 0.000 description 8
- 239000000126 substance Substances 0.000 description 8
- 238000005097 cold rolling Methods 0.000 description 7
- 238000001816 cooling Methods 0.000 description 7
- 238000004804 winding Methods 0.000 description 7
- 230000001276 controlling effect Effects 0.000 description 6
- 238000002474 experimental method Methods 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 5
- 238000009713 electroplating Methods 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- 239000002436 steel type Substances 0.000 description 4
- 239000005028 tinplate Substances 0.000 description 4
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 238000009749 continuous casting Methods 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 238000005238 degreasing Methods 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 229910052717 sulfur Inorganic materials 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 238000003723 Smelting Methods 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 229910052758 niobium Inorganic materials 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 238000002791 soaking Methods 0.000 description 2
- 230000000007 visual effect Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- NWONKYPBYAMBJT-UHFFFAOYSA-L zinc sulfate Chemical compound [Zn+2].[O-]S([O-])(=O)=O NWONKYPBYAMBJT-UHFFFAOYSA-L 0.000 description 2
- 229960001763 zinc sulfate Drugs 0.000 description 2
- 229910000368 zinc sulfate Inorganic materials 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 102220479482 Puromycin-sensitive aminopeptidase-like protein_C21D_mutation Human genes 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 230000003679 aging effect Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 229910001567 cementite Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000000875 corresponding effect Effects 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000011010 flushing procedure Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- KFZAUHNPPZCSCR-UHFFFAOYSA-N iron zinc Chemical compound [Fe].[Zn] KFZAUHNPPZCSCR-UHFFFAOYSA-N 0.000 description 1
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- QELJHCBNGDEXLD-UHFFFAOYSA-N nickel zinc Chemical compound [Ni].[Zn] QELJHCBNGDEXLD-UHFFFAOYSA-N 0.000 description 1
- 231100000989 no adverse effect Toxicity 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000001301 oxygen Substances 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
- 239000000047 product Substances 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/34—Pretreatment of metallic surfaces to be electroplated
- C25D5/36—Pretreatment of metallic surfaces to be electroplated of iron or steel
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
- B21B3/02—Rolling special iron alloys, e.g. stainless steel
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/22—Electroplating: Baths therefor from solutions of zinc
Description
【０００１】[0001]
【産業上の利用分野】本発明は、木目状疵が少なく表面
性状の良好な電気亜鉛めっき用鋼板および電気亜鉛めっ
き鋼板、並びにこれらの鋼板を効率よく製造することの
できる方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrogalvanized steel sheet and an electrogalvanized steel sheet having few wood grain defects and good surface properties, and a method for efficiently producing these steel sheets.
【０００２】[0002]
【従来の技術】電気亜鉛めっき鋼板は、美麗で均質性の
高い外観が得られるという理由から、自動車や家庭用電
気製品等の外板材または建築材料等の他、近年では、電
子・家電製品のシャーシやコンピューターケース等にも
使用される等、その利用分野が大幅に拡大している。こ
の様な用途の拡大に伴って、電気亜鉛めっき鋼板におけ
る表面性状やめっき外観の向上が強く切望されている。2. Description of the Related Art In recent years, electrogalvanized steel sheets have been used not only for outer panels or building materials of automobiles and household electric appliances, but also in recent years for electronic and home electric appliances because they have a beautiful and highly uniform appearance. It is used in chassis and computer cases, and its fields of use are expanding significantly. With the expansion of such uses, there is a strong demand for improvement in surface properties and plating appearance of electrogalvanized steel sheets.
【０００３】このうち電気亜鉛めっき鋼板の表面に現れ
る疵としては、木目状疵、白すじ等が挙げられるが、こ
のうち木目状疵は、めっき処理前の冷延鋼板では殆ど検
出されず、めっきを施すことによって初めて顕著に現れ
ることから、その対策に苦慮しているのが現状である。Among the flaws appearing on the surface of the electrogalvanized steel sheet, wood grain flaws, white streaks and the like can be mentioned. Of these, wood grain flaws are hardly detected in cold-rolled steel sheets before plating, and At present, it is difficult to take countermeasures because it becomes noticeable for the first time.
【０００４】この様な木目状疵を改善するための方法と
して、例えば特公昭５７−２６３５４号には、電気ブリ
キ表面に現れる木目状の模様（木目模様）を防止すると
共に表面光沢を改善することのできる電気ブリキの製造
方法が開示されている。この方法は、表面錫をフローメ
ルト処理する際、フラックス中に界面活性剤を添加する
ことによりフラッシングの効果を強化し、木目模様の発
生を防止しようとするものである。しかしながら、上記
方法は電気ブリキを対象としたものであり、且つ電気ブ
リキ製造過程において通常施されるフローメルト処理を
制御することによって上記目的を達成しようとするもの
であるので、めっきの種類が異なり且つ該フローメルト
処理を必ずしも必要としない電気亜鉛めっき鋼板の製造
に、上記方法が有効に作用するかどうかは不明である。
しかも、上記フローメルト処理を施さずに電気亜鉛めっ
き鋼板を製造した場合に発生する木目状疵を防止する方
法については、依然として開示されていないのが現状で
ある。As a method for improving such a grain defect, for example, Japanese Patent Publication No. 57-26354 discloses a method of preventing a grain pattern (wood pattern) appearing on the surface of an electric tin plate and improving the surface gloss. A method for producing an electric tinplate is disclosed. This method aims to enhance the flushing effect by adding a surfactant to the flux when the surface tin is subjected to the flow melt treatment, and to prevent the occurrence of a grain pattern. However, the above-mentioned method is intended for electric tinplate, and since the above-mentioned method is intended to achieve the above-mentioned object by controlling a flow melt treatment usually performed in an electric tinplate manufacturing process, the type of plating is different. Further, it is not clear whether the above-mentioned method works effectively for the production of electrogalvanized steel sheet which does not necessarily require the flow melt treatment.
Moreover, at present, a method of preventing grain-like flaws generated when an electrogalvanized steel sheet is manufactured without performing the above-mentioned flow melt treatment has not yet been disclosed.
【０００５】[0005]
【発明が解決しようとする課題】本発明はこうした事情
に着目してなされたものであって、その目的は、耐木目
状疵性に優れた表面性状の良好な電気亜鉛めっき用鋼板
およびめっき鋼板、並びにこれらの鋼板を効率よく製造
することのできる方法を提供することにある。SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to provide a galvanized steel sheet and a galvanized steel sheet having excellent surface properties and excellent grain resistance. Another object of the present invention is to provide a method capable of efficiently producing these steel sheets.
【０００６】[0006]
【課題を解決するための手段】上記目的を達成し得た本
発明の電気亜鉛めっき用鋼板とは、鋼中のＮｉ量を0.06
％以下に制限すると共に、鋼板表層部のＮｉ濃度が１０
原子％以下であって且つ鋼板表面から２００Åの深さ位
置におけるＮｉ濃度が４原子％以下である点に要旨を有
するものである。鋼中のＮｉ量は0.03％以下であること
が好ましい。The steel sheet for electrogalvanizing of the present invention, which has achieved the above object, has a Ni content of 0.06%.
% And the Ni concentration in the surface layer of the steel sheet is 10% or less.
The gist is that the Ni concentration at a depth of 200% or less from the steel sheet surface is 200% or less. The amount of Ni in the steel is preferably 0.03% or less.
【０００７】また、上記目的を達成し得た本発明の電気
亜鉛めっき鋼板とは、上記電気亜鉛めっき用鋼板に電気
亜鉛めっきが施されたものである。このめっき層表面
に、更にクロメート皮膜および有機樹脂皮膜が順次施さ
れためっき鋼板は、本発明の好ましい実施態様である。
これらの電気亜鉛めっき用鋼板およびめっき鋼板は、電
気製品用の外板材等に好適に使用される。[0007] The electrogalvanized steel sheet of the present invention, which has achieved the above object, is the above-mentioned electrogalvanized steel sheet which is electrogalvanized. A plated steel sheet in which a chromate film and an organic resin film are sequentially applied to the surface of the plating layer is a preferred embodiment of the present invention.
These electrogalvanized steel sheets and galvanized steel sheets are suitably used as outer plate materials for electric products and the like.
【０００８】次に、上記目的を達成し得た本発明の電気
亜鉛めっき用鋼板の製造方法とは、Ｎｉ量を0.06％以下
に抑制した鋼材を使用し、熱間圧延における鋼材の表面
温度を１２００℃以下に抑えると共に抽出温度を１０５
０〜１２００℃に制御することにより、電気亜鉛めっき
用鋼板の表層部のＮｉ濃度を１０原子％以下、および鋼
板表面から２００Åの深さ位置におけるＮｉ濃度を４原
子％以下に抑制する点に要旨を有する。ここで、鋼中の
Ｎｉ量は0.03％以下とすることが好ましい。上記方法に
用いられる鋼材においてＮｉ以外の元素の好ましい含有
量は、Ｃ≦0.10％，Ｓｉ≦0.2 ％，Ｍｎ≦1.8 ％，Ｐ≦
0.10％，Ａｌ：0.005 〜0.10％，Ｎ≦0.010 ％であり、
必要に応じてＴｉ：0.005 〜0.1 ％および／またはＮ
ｂ：0.005〜0.1 ％、およびＢ：0.0005〜0.003 ％の要
件を満たすことが推奨される。本発明の電気亜鉛めっき
鋼板は、上記の様にして得られた電気亜鉛めっき用鋼板
に電気亜鉛めっきを施すことによって製造することがで
きる。Next, the method for producing a steel sheet for electrogalvanizing according to the present invention, which achieves the above object, uses a steel material in which the Ni content is suppressed to 0.06% or less, and reduces the surface temperature of the steel material in hot rolling. Keep the temperature below 1200 ° C and the extraction temperature at 105
By controlling the temperature to 0 to 1200 ° C., the Ni concentration in the surface portion of the steel sheet for electrogalvanizing is suppressed to 10 atomic% or less, and the Ni concentration at a depth of 200 ° from the steel sheet surface is suppressed to 4 atomic% or less. Having. Here, the Ni content in the steel is preferably set to 0.03% or less. Preferred contents of elements other than Ni in the steel used in the above method are C ≦ 0.10%, Si ≦ 0.2%, Mn ≦ 1.8%, P ≦
0.10%, Al: 0.005 to 0.10%, N ≦ 0.010%,
If necessary, Ti: 0.005 to 0.1% and / or N
It is recommended that the requirements of b: 0.005-0.1% and B: 0.0005-0.003% be met. The electrogalvanized steel sheet of the present invention can be manufactured by subjecting the steel sheet for electrogalvanization obtained as described above to electrogalvanization.
【０００９】[0009]
【作用】以下の記載では、電気亜鉛めっき用鋼板と電気
亜鉛めっき鋼板を明瞭に区別すべく、便宜上、電気亜鉛
めっき用鋼板をめっき原板と呼ぶ場合がある。本発明者
らは、電気亜鉛めっき鋼板において木目状疵が発生する
原因について鋭意検討を重ねてきた結果、この様な木目
状疵の見られる木目部分には、木目状疵の見られない正
常部分に比べてＮｉ濃化量が多いことを見出した。そこ
で、この様なＮｉ濃化量を制御することができれば、木
目状疵の発生を有効に防止することができると考え、鋼
中成分およびめっき処理前の製造条件に着目して更に実
験を行うことにより本発明を完成したのである。In the following description, for the sake of clarity, the steel sheet for electrogalvanizing may be referred to as the base sheet for convenience in order to clearly distinguish the steel sheet for electrogalvanizing from the steel sheet for electrogalvanizing. The present inventors have intensively studied the cause of the occurrence of grain-like flaws in an electrogalvanized steel sheet. As a result, the grain part where such grain-like flaws are seen is a normal part where grain-like flaws are not seen. It was found that the amount of Ni enrichment was larger than that of. Therefore, if it is possible to control the amount of Ni enrichment in such a manner, it is considered that the occurrence of wood grain flaws can be effectively prevented, and further experiments are conducted by focusing on the components in steel and the manufacturing conditions before plating. Thus, the present invention has been completed.
【００１０】以下、本発明の構成について、その実験経
緯を追って説明する。以下の実験では、化学成分として
Ｃ：0.050 ％，Ｓｉ：0.01％，Ｍｎ：0.20％，Ｐ：0.01
5 ％，Ｓ：0.015 ％，Ａｌ：0.045 ％，Ｎ：0.060 ％を
含有する鋼に、Ｎｉ量を0.004 〜0.10％の範囲で種々変
化させた５種類の鋼を用いた。これらの鋼を実験室規模
で溶製した後、粗圧延により３０ｍｍ厚のスラブとし
た。次に、熱間圧延時の加熱抽出温度を１０５０〜１３
００℃の範囲で変化させて熱間圧延した後、仕上温度：
９２０℃で３．６ｍｍ厚に仕上げ、５００℃×１時間の
巻取処理を行い、酸洗処理を経て熱延鋼板としてから冷
間圧延を施して０．８ｍｍ厚の冷延鋼板を得た。この様
にして得られた冷延鋼板に、６５０℃×２０時間の均熱
箱焼鈍、０．５％の調質圧延を施した後、硫酸亜鉛めっ
き浴中で電気めっきを行い、更にクロメート処理および
有機樹脂被覆処理を施すことによりめっき付着量が２０
／２０ｇ／ｍ2 の電気めっき鋼板を得た。なお、電気め
っき鋼板の表面に検出される木目状疵の評価は、下記の
様にして行った。Hereinafter, the configuration of the present invention will be described with reference to experimental details. In the following experiments, C: 0.050%, Si: 0.01%, Mn: 0.20%, P: 0.01
As steel containing 5%, S: 0.015%, Al: 0.045%, and N: 0.060%, five kinds of steels in which the amount of Ni was variously changed in the range of 0.004 to 0.10% were used. After smelting these steels on a laboratory scale, the slabs were 30 mm thick by rough rolling. Next, the hot extraction temperature during hot rolling was set to 1050 to 13
After hot rolling at a temperature in the range of 00 ° C., the finishing temperature is:
Finishing at 920 ° C. to a thickness of 3.6 mm, winding treatment at 500 ° C. × 1 hour, hot-rolled steel sheet after pickling treatment, and then cold rolling to obtain a 0.8-mm thick cold-rolled steel sheet. The cold-rolled steel sheet thus obtained is subjected to a soaking box annealing at 650 ° C. × 20 hours, a temper rolling of 0.5%, and then electroplating in a zinc sulfate plating bath, followed by a chromate treatment. And by applying an organic resin coating treatment, the coating weight is 20
/ 20 g / m 2 of the electroplated steel sheet was obtained. In addition, the evaluation of the grain-like flaw detected on the surface of the electroplated steel sheet was performed as follows.
【００１１】即ち、木目状疵評価用サンプルとして、上
記製造工程によって得られた冷延鋼板１枚につき、幅１
００ｍｍ×長さ１８０ｍｍにカットした冷延鋼板サンプ
ルを６枚用意し、上記と同様にしてめっき処理を行うこ
とにより電気亜鉛めっき鋼板を得た。各サンプルの表面
積を１０等分した１０視野、合計６０視野において発生
した木目状疵をカウントし、下式により木目状疵の発生
率を算出した。 木目状疵の発生率（％）＝（総発生数／６０）×１００That is, as a sample for wood grain defect evaluation, the width of one cold-rolled steel sheet
Six cold-rolled steel sheet samples cut to 00 mm x 180 mm in length were prepared and subjected to a plating treatment in the same manner as above to obtain an electrogalvanized steel sheet. The grain-like flaws generated in 10 visual fields obtained by dividing the surface area of each sample into ten equal to 60 visual fields were counted, and the occurrence rate of the grain-like flaws was calculated by the following formula. Rate of occurrence of wood grain defects (%) = (total number of occurrences / 60) × 100
【００１２】図１に、加熱抽出温度を１１５０℃と一定
にした場合における、木目状疵の発生率と鋼中Ｎｉ量と
の関係を示す。図１から明らかな様に、Ｎｉ量の減少に
伴って木目状疵の発生率も減少していき、Ｎｉ量を0.06
％以下にすれば、耐木目状疵性の向上の目安となる木目
状疵発生率：１０％以下を達成できることが分かった。FIG. 1 shows the relationship between the occurrence rate of wood grain flaws and the amount of Ni in steel when the heat extraction temperature is kept constant at 1150 ° C. As is evident from FIG. 1, the incidence of grain-like flaws decreases as the Ni content decreases, and the Ni content is reduced to 0.06.
%, It can be seen that a grain-like flaw occurrence rate of 10% or less, which is a measure for improving the grain-like flaw resistance, can be achieved.
【００１３】図２には、Ｎｉ量を0.012 ％と一定にした
場合における、木目状疵の発生率と加熱抽出温度との関
係を示す。図２から明らかな様に、加熱抽出温度の低下
と共に木目状疵の発生率も減少していき、該抽出温度を
１２００℃以下にすれば、目標値である木目状疵発生
率：１０％以下を達成できることが分かった。FIG. 2 shows the relationship between the occurrence rate of wood grain flaws and the heat extraction temperature when the Ni content is fixed at 0.012%. As is clear from FIG. 2, the rate of occurrence of grain defects decreases with a decrease in the heat extraction temperature. If the extraction temperature is set to 1200 ° C. or lower, the target value of the grain defect rate is 10% or less. Was found to be achieved.
【００１４】これらの実験結果から、耐木目状疵性に優
れた電気亜鉛めっき鋼板を製造するに当たっては、鋼中
のＮｉ量を0.06％以下に抑制すると共に、熱間圧延時に
おける加熱抽出温度を１２００℃以下に制御しためっき
原板を使用することが有効であることが分かった。From the results of these experiments, in producing an electrogalvanized steel sheet having excellent wood grain resistance, the amount of Ni in the steel was suppressed to 0.06% or less, and the heat extraction temperature during hot rolling was reduced. It was found that it is effective to use a plating base plate controlled at 1200 ° C. or lower.
【００１５】次に、めっき原板表層部からの深さとＮｉ
濃度との関係について調べた。詳細には、鋼中のＮｉ量
を0.05％と一定にした鋼を用い、前述と同様に処理する
ことにより得られた電気亜鉛めっき鋼板において、木目
状疵の発生した部分と発生していない部分のめっき層
を、アルカリ水溶液（６０℃、１０％ＮａＯＨ水溶液）
を用いて除去して未めっき（裸状態）のめっき原板とし
た後、オージェ分析法により表層部からの深さ分析を行
った。図３に、めっき原板表面からの深さにおけるＮｉ
濃度をグラフ化したＮｉ濃化曲線を示す。同図から、木
目状疵の発生は、鋼板表面層に濃化するＮｉの濃化曲線
と相関関係が高く、濃化程度の大きい鋼板では木目状疵
が多量に発生するのに対し、濃化程度の小さい鋼板では
ほとんど発生しないことが分かる。更に、木目状疵の発
生していない正常部では、めっき原板からの或る一定深
さにおけるＮｉ濃度が常に４原子％以下になっているこ
とも分かった。即ち、めっき原板表面からの、或る深さ
部分におけるＮｉ濃度が所定範囲に制御されためっき原
板は、耐木目状疵性に優れた電気亜鉛めっき用鋼板とし
て有用であることが示唆される。Next, the depth from the surface layer of the plating base sheet and the Ni
The relationship with the concentration was examined. Specifically, in a galvanized steel sheet obtained by using a steel in which the amount of Ni in the steel is fixed to 0.05% and performing the same treatment as described above, a portion where grain-like defects are generated and a portion where no grain is generated The plating layer of (1) is made of an alkaline aqueous solution (60 ° C., 10% NaOH aqueous solution)
Then, the unplated (bare state) plating original plate was removed by using the method described above, and the depth from the surface layer was analyzed by Auger analysis. FIG. 3 shows the Ni at the depth from the surface of the original plating plate.
3 shows a Ni concentration curve in which the concentration is graphed. From the figure, it can be seen that the occurrence of grain defects is highly correlated with the concentration curve of Ni concentrated on the steel sheet surface layer. It can be seen that almost no steel sheet occurs. Furthermore, it was also found that in a normal portion where no grain defects were generated, the Ni concentration at a certain constant depth from the original plating plate was always 4 atomic% or less. That is, it is suggested that a plated original sheet in which the Ni concentration at a certain depth from the surface of the original plated sheet is controlled within a predetermined range is useful as a steel sheet for electrogalvanizing having excellent wood grain resistance.
【００１６】そこで、めっき原板表層部におけるＮｉ濃
度と、めっき表面の外観との関係を明らかにすると共
に、Ｎｉ濃度が４原子％以下になる深さとめっき外観と
の関係についても調べるべく、更に多くのサンプルを用
いて深さ分析を行った。図４に、めっき原板表層部にお
けるＮｉ濃度と表面外観の関係を示し、図５には、Ｎｉ
濃度が４原子％以下になる深さと表面外観の関係を示
す。なお、めっき表面外観の性状は、木目状疵を中心に
めっき表面に現れる模様を目視にて観察し、下記基準で
評価した。 ○：めっき表面の性状が良好 △：めっき表面に模様が若干見られる ×：めっき表面に模様が鮮明に認められるTherefore, in order to clarify the relationship between the Ni concentration in the surface layer portion of the original plating plate and the appearance of the plating surface, and to investigate the relationship between the depth at which the Ni concentration becomes 4 atomic% or less and the plating appearance, more and more were investigated. Was subjected to depth analysis. FIG. 4 shows the relationship between the Ni concentration and the surface appearance in the surface layer portion of the original plating plate.
The relationship between the depth at which the concentration becomes 4 atomic% or less and the surface appearance is shown. The appearance of the plating surface was evaluated by visually observing a pattern appearing on the plating surface with a focus on wood grain defects, and evaluated according to the following criteria. ：: Good property of plating surface △: Some pattern is seen on plating surface ×: Pattern is clearly seen on plating surface
【００１７】これらの結果から、めっき原板表層部にお
けるＮｉ濃度が１０原子％以下、且つ鋼板表面から２０
０Åの深さ位置におけるＮｉ濃度が４原子％以下であれ
ば、木目状疵もほとんど発生せず表面性状の良好なめっ
き鋼板が得られることが分かった。From these results, it was found that the Ni concentration in the surface layer portion of the original plating sheet was 10 atomic% or less and that
It was found that if the Ni concentration at a depth of 0 ° was 4 atomic% or less, a plated steel sheet having good surface properties was obtained with almost no grain-like flaws.
【００１８】そして、上記の様なＮｉ濃度が制御された
めっき原板は、鋼中のＮｉ量および熱間圧延時における
加熱抽出温度を制御することによって初めて得られるこ
とも分かった。これらの実験結果を確認するために、更
に別の鋼材（Ｔｉ添加鋼）を用いて上記と全く同様にし
て実験を行った。[0018] It was also found that the above-mentioned plated base sheet having a controlled Ni concentration can be obtained for the first time by controlling the amount of Ni in the steel and the heat extraction temperature during hot rolling. In order to confirm the results of these experiments, experiments were performed in exactly the same manner as above using another steel material (Ti-added steel).
【００１９】即ち、化学成分としてＣ：0.003 ％，Ｓ
ｉ：0.01％，Ｍｎ：0.15％，Ｐ：0.007 ％，Ｓ：0.010
％，Ａｌ：0.035 ％，Ｎ：0.0025％，Ｔｉ：0.065 ％を
含有する鋼に、Ｎｉ量を0.004 〜0.10％の範囲で種々変
化させた５種類の鋼を用いた。これらの鋼を実験室規模
で溶製した後、上記と同様にして熱間圧延した後、仕上
温度：９２０℃で３．６ｍｍ厚に仕上げ、６８０℃×１
時間の巻取処理を行い、酸洗処理を経て熱延鋼板として
から冷間圧延を施して０．８ｍｍ厚の冷延鋼板を得た。
この様にして得られた冷延鋼板に、８００℃×１分間の
連続焼鈍、０．５％の調質圧延を施した後、硫酸亜鉛め
っき浴中で電気めっきを行い、更にクロメート処理およ
び有機樹脂被覆処理を施すことによりめっき付着量が２
０／２０ｇ／ｍ2 の電気めっき鋼板を得た。この様にし
て得られた電気めっき鋼板の木目状疵について、上記と
同様にして評価した。That is, as a chemical component, C: 0.003%, S
i: 0.01%, Mn: 0.15%, P: 0.007%, S: 0.010
%, Al: 0.035%, N: 0.0025%, and Ti: 0.065%. Five types of steels with various Ni contents in the range of 0.004 to 0.10% were used. After smelting these steels on a laboratory scale, they were hot-rolled in the same manner as described above, and finished to a thickness of 3.6 mm at a finishing temperature of 920 ° C. and 680 ° C. × 1.
After performing a winding process for a long time, a hot-rolled steel sheet was passed through an acid washing process, and then cold-rolled to obtain a cold-rolled steel sheet having a thickness of 0.8 mm.
The cold-rolled steel sheet thus obtained is subjected to continuous annealing at 800 ° C. for 1 minute and temper rolling of 0.5%, then electroplating in a zinc sulfate plating bath, and further chromate treatment and organic treatment. Resin coating treatment reduces plating adhesion to 2
An electroplated steel sheet of 0/20 g / m 2 was obtained. The grain defects of the electroplated steel sheet thus obtained were evaluated in the same manner as described above.
【００２０】図６に、加熱抽出温度を１１５０℃と一定
にした場合における、木目状疵の発生率と鋼中Ｎｉ量と
の関係を示す。図６から明らかな様に、Ｎｉ量を0.06％
以下にすれば、耐木目状疵性の向上の目安となる木目状
疵発生率：１０％以下を達成できることが分かった。FIG. 6 shows the relationship between the occurrence rate of grain-like flaws and the amount of Ni in steel when the heat extraction temperature is kept constant at 1150 ° C. As is clear from FIG.
It has been found that the following can achieve a grain-like flaw occurrence rate of 10% or less, which is a measure for improving the grain-like flaw resistance.
【００２１】図７には、Ｎｉ量を0.012 ％と一定にした
場合における、木目状疵の発生率と加熱抽出温度との関
係を示す。図７から明らかな様に、加熱抽出温度の低下
と共に木目状疵の発生率も減少していき、該抽出温度を
１２００℃以下にすれば、目標値である木目状疵発生
率：１０％以下を達成できることが分かった。FIG. 7 shows the relationship between the occurrence rate of wood grain flaws and the heat extraction temperature when the Ni content is fixed at 0.012%. As is clear from FIG. 7, the rate of occurrence of grain defects decreases as the heating extraction temperature decreases. If the extraction temperature is set to 1200 ° C. or less, the target value of the grain defect rate is 10% or less. Was found to be achieved.
【００２２】これらの実験結果は、前述の結果と全く同
じであり、耐木目状疵性に優れた電気亜鉛めっき鋼板を
製造するに当たっては、鋼中のＮｉ量を0.06％以下に抑
制すると共に、熱間圧延時の加熱抽出温度を１２００℃
以下に制御しためっき原板を使用することが有効である
ことを確認することができた。The results of these experiments are exactly the same as the above-mentioned results. In producing an electrogalvanized steel sheet having excellent wood grain resistance, the amount of Ni in the steel should be suppressed to 0.06% or less. Heat extraction temperature of 1200 ° C during hot rolling
It was confirmed that it is effective to use the plating base plate controlled as follows.
【００２３】次に、めっき原板表層部からの深さとＮｉ
濃度との関係について、鋼中のＮｉ量を0.01％と一定に
した鋼を用いたこと以外は上記と同様にして調べた。図
８に、めっき原板表面からの深さにおけるＮｉ濃度をグ
ラフ化したＮｉ濃化曲線を、図９に、めっき原板表層部
におけるＮｉ濃度と表面外観の関係を、更に図１０に、
Ｎｉ濃度が４原子％以下になる深さと表面外観の関係を
示す。Next, the depth from the surface layer of the original plating sheet and the Ni
The relationship with the concentration was examined in the same manner as described above, except that a steel having a constant Ni content of 0.01% was used. FIG. 8 is a graph showing the Ni concentration curve obtained by graphing the Ni concentration at a depth from the surface of the original plating plate. FIG. 9 is a graph showing the relationship between the Ni concentration in the surface layer portion of the original plating plate and the surface appearance.
The relationship between the depth at which the Ni concentration becomes 4 atomic% or less and the surface appearance is shown.
【００２４】これらの結果は、前述の実験結果と全く同
じであった。即ち、めっき原板表層部におけるＮｉ濃度
が１０原子％以下、且つ鋼板最表面から２００Åの深さ
位置におけるＮｉ濃度が４原子％以下であれば、木目状
疵もほとんど発生せず表面性状の良好なめっき鋼板が得
られることが分かった。These results were exactly the same as the experimental results described above. That is, if the Ni concentration in the surface layer portion of the plated original sheet is 10 atomic% or less and the Ni concentration at a depth of 200 ° from the outermost surface of the steel sheet is 4 atomic% or less, almost no grain-like flaw is generated and the surface quality is good. It was found that a plated steel sheet was obtained.
【００２５】本発明の構成は、以上の様な実験結果に基
づいて決定されたものであり、この様な構成とすること
により、木目状疵の発生に対して悪影響を及ぼすＮｉ濃
化層を制御することができる。The structure of the present invention has been determined based on the above experimental results. By adopting such a structure, it is possible to form a Ni-enriched layer which has a bad influence on the occurrence of wood grain flaws. Can be controlled.
【００２６】この様に鋼中のＮｉ量および熱間圧延にお
ける加熱抽出温度を制御することにより耐木目状疵性を
改善することのできる理由は詳細には不明であるが、以
下のことが考えられる。The reason why the grain resistance can be improved by controlling the amount of Ni in the steel and the hot extraction temperature in hot rolling as described above is unknown in detail, but the following is considered. Can be
【００２７】熱間圧延時の加熱抽出温度が高くなると、
鋼片またはスラブの酸化が促進されスケール層が厚くな
る。鋼中成分のうちＳｉ，Ｍｎ，Ｆｅ等の酸化され易い
元素は酸素と反応してスケール層を形成するが、酸化さ
れ難いＮｉは鋼片またはスラブ表面の地鉄中に残存し、
該スケールに見合う分だけ濃化する結果、Ｎｉ濃化部が
形成される。この様にして形成されたＮｉ濃化部分は、
Ｎｉ濃化の無い部分に比べて酸化され難いため、スケー
ル／地鉄界面は、熱間圧延前における平滑状態から、熱
間圧延時には、混合層と呼ばれる不均一且つ複雑に入り
組んだ状態へと変化する。このＮｉ濃化部は酸洗処理に
よっても溶解せず、そのまま表面に残存するので、この
様な混合層を形成した鋼片を用いて通常の熱間圧延、酸
洗、冷間圧延および焼鈍処理を順次施しためっき原板の
表面には、平面的に見ると、Ｎｉ濃化部が圧延方向に不
均一に分布した木目状模様が形成された状態になってい
る。この様な表面状態を有する鋼板に電気亜鉛めっきを
施すと、Ｎｉ濃化部と非濃化部の間で電解電位が異なる
ため、表面に電析する亜鉛めっき結晶の大きさや成長方
向が変化し、めっき表面に木目状疵となって観察される
ことになる。When the hot extraction temperature during hot rolling increases,
Oxidation of the billet or slab is promoted and the scale layer becomes thicker. Of the components in the steel, easily oxidizable elements such as Si, Mn, and Fe react with oxygen to form a scale layer, but hardly oxidized Ni remains in the steel slab or slab surface ground iron,
As a result of enrichment by an amount corresponding to the scale, a Ni enriched portion is formed. The Ni-enriched portion thus formed is
The scale / ground iron interface changes from a smooth state before hot rolling to an uneven and complicated intricate state called a mixed layer during hot rolling, because it is less oxidized than the part without Ni concentration. I do. Since this Ni-enriched portion does not dissolve even by the pickling treatment and remains on the surface as it is, normal hot rolling, pickling, cold rolling and annealing treatment are performed using a steel slab having such a mixed layer formed thereon. In a plan view, a grained pattern in which the Ni-enriched portions are unevenly distributed in the rolling direction is formed on the surface of the plating base sheet sequentially subjected to the following steps. When electrogalvanizing a steel sheet having such a surface condition, the electrolytic potential differs between the Ni-enriched portion and the non-enriched portion, and the size and growth direction of the zinc-plated crystal deposited on the surface change. This is observed as a grain on the plating surface.
【００２８】本発明の如く鋼中Ｎｉ量を低減するとＮｉ
濃化部の形成が抑えられると共に、熱延時における加熱
抽出温度を低めに制御することによってＮｉ濃化の程度
が抑制されるので、結果的に、耐木目状疵性に優れた電
気亜鉛めっき鋼板が得られるのである。When the amount of Ni in steel is reduced as in the present invention, Ni
The formation of the concentrated portion is suppressed, and the degree of Ni concentration is suppressed by controlling the heating extraction temperature at the time of hot rolling to a lower temperature. As a result, an electrogalvanized steel sheet having excellent wood grain-like flaw resistance is obtained. Is obtained.
【００２９】この様に、本発明のめっき原板では鋼中の
Ｎｉ量を制御する点に第１の特徴を有する。即ち、めっ
き原板における鋼中のＮｉ量は0.06％以下であることが
必要である。好ましくは0.03％以下、より好ましくは0.
02％以下とする。更に、めっき原板表層部におけるＮｉ
濃度が１０原子％以下（好ましくは８原子％以下）、お
よび原板表面から２００Åの深さ位置におけるＮｉ濃度
が４原子％以下（好ましくは３原子％以下）である点に
第２の特徴を有する。As described above, the original plate of the present invention has the first feature in that the amount of Ni in steel is controlled. That is, it is necessary that the amount of Ni in the steel in the plating base sheet is 0.06% or less. Preferably 0.03% or less, more preferably 0.1%.
02% or less. In addition, Ni
The second feature is that the concentration is 10 atomic% or less (preferably 8 atomic% or less) and the Ni concentration at a depth of 200 ° from the surface of the original plate is 4 atomic% or less (preferably 3 atomic% or less). .
【００３０】この様な要件を具備する本発明めっき原板
を製造するには、上述の様に予めＮｉ量を制御した鋼を
用いてもよいし、あるいはスクラップ合金等を用いるこ
とも可能である。いずれにせよ、原料となる鋼材中のＮ
ｉ量を上記範囲内に制御しておけば良い。In order to manufacture the plating base plate of the present invention satisfying such requirements, it is possible to use steel in which the amount of Ni is controlled in advance as described above, or it is also possible to use a scrap alloy or the like. In any case, N in the raw steel material
The i amount may be controlled within the above range.
【００３１】更に、熱間圧延に際しては、鋼材の表面温
度を１２００℃以下に抑えると共に抽出温度を１０５０
〜１２００℃に制御することが必要である。好ましい上
限値は１１５０℃である。一方、加熱抽出温度は低けれ
ば低い程、耐木目状疵性の向上に有効であるが、低すぎ
ると熱間圧延が困難となるのでその下限を１０５０℃と
する。好ましい下限値は１０８０℃である。Further, at the time of hot rolling, the surface temperature of the steel material is suppressed to 1200 ° C. or less and the extraction temperature is set to 1050 ° C.
It is necessary to control the temperature to ~ 1200 ° C. A preferred upper limit is 1150 ° C. On the other hand, the lower the heating extraction temperature is, the more effective it is in improving the grain resistance, but if it is too low, the hot rolling becomes difficult, so the lower limit is set to 1050 ° C. A preferred lower limit is 1080 ° C.
【００３２】ここで、鋼中の好ましいＮｉ量は熱間圧延
時の加熱抽出温度とも相関性が高いことは前述した通り
であり、例えばＮｉ量が０．０３０％以下に制御された
鋼を用いた場合には、上記加熱抽出温度を１１３０〜１
２００℃（好ましくは１１４０〜１１９０℃）に制御す
ることが好ましく、Ｎｉ量が０．０３１〜０．０６０％
に制御された鋼を用いた場合には、上記加熱抽出温度を
１０５０〜１１９０℃（好ましくは１０８０〜１１６０
℃）に制御することが好ましい。この様にして製造され
ためっき原板に通常の電気亜鉛めっきを施すことによっ
て、耐木目状疵性に優れた本発明電気亜鉛めっき鋼板が
得られる。Here, as described above, the preferable Ni content in the steel has a high correlation with the hot extraction temperature during hot rolling, as described above. For example, a steel in which the Ni content is controlled to 0.030% or less is used. If it is, the above-mentioned heat extraction temperature is 1130-1.
It is preferable to control the temperature to 200 ° C (preferably 1140 to 1190 ° C), and the Ni content is 0.031 to 0.060%.
In the case of using steel controlled to a temperature of 1050 to 1190 ° C. (preferably 1800 to 1160 ° C.).
C). By subjecting the thus-prepared plated sheet to normal electrogalvanizing, an electrogalvanized steel sheet of the present invention having excellent wood grain resistance can be obtained.
【００３３】以上、本発明の必須構成要件について説明
したが、以下の記載では、更に加工性等を向上させるこ
とのできる好ましい要件について記載する。まず、本発
明に用いられる鋼組成について、Ｎｉ以外の元素の好ま
しい含有量は以下の通りである。As described above, the essential components of the present invention have been described. In the following description, preferable requirements that can further improve workability and the like will be described. First, regarding the steel composition used in the present invention, preferable contents of elements other than Ni are as follows.
【００３４】Ｃ≦0.10％ Ｃを過剰に添加すると、炭化物であるセメンタイトが析
出し、めっき鋼板の降伏点や強度が高くなると共に、加
工性（特にプレス加工性）が低下する他、Ｃを固定する
ために適宜添加されるＴｉ量やＮｂ量（後述する）も多
くなってコスト高となるので、その上限を0.10％とする
ことが好ましい。より好ましい上限値は0.006 ％であ
る。一方、その下限値は特に規定されないが、Ｃ量の低
減には溶鋼での脱ガス処理が必要であり、0.0005％未満
に制御しようとするとコストが非常に高くなるので、そ
の下限を0.0005％とすることが好ましい。C ≦ 0.10% When C is excessively added, cementite, which is a carbide, precipitates, increasing the yield point and strength of the plated steel sheet, lowering workability (particularly, press workability), and fixing C. Therefore, the amount of Ti or Nb (described later) appropriately added increases and the cost increases, so the upper limit is preferably set to 0.10%. A more preferred upper limit is 0.006%. On the other hand, the lower limit is not particularly specified, but a reduction in the amount of C requires degassing treatment with molten steel, and if the control is made to be less than 0.0005%, the cost becomes extremely high. Is preferred.
【００３５】Ｓｉ≦0.2 ％ Ｓｉは延性を損なうことなく高強度を得るのに有用な元
素である。しかしながら、0.2 ％を超えて添加すると、
めっき性や化成処理性が低下するため、その上限を0.2
％とすることが好ましい。特に軟鋼板の場合には、0.20
％以下とすることが推奨される。Si ≦ 0.2% Si is a useful element for obtaining high strength without impairing ductility. However, when added above 0.2%,
Since the plating properties and chemical conversion properties decrease, the upper limit is 0.2
% Is preferable. Especially for mild steel sheets, 0.20
% Is recommended.
【００３６】Ｍｎ≦1.8 ％ Ｍｎは、めっき性や化成処理性にはほとんど影響を及ぼ
さずに高強度を得るのに有用な元素であり、高強度化に
応じて1.8 ％まで添加することが可能である。特に、高
度の加工性を必要とする軟鋼板の場合には0.20％以下と
することが好ましい。Mn ≦ 1.8% Mn is a useful element for obtaining high strength without substantially affecting plating properties or chemical conversion treatment properties. Mn can be added up to 1.8% depending on the strength. It is. In particular, in the case of a mild steel sheet requiring high workability, the content is preferably set to 0.20% or less.
【００３７】Ｐ≦0.10％ ＰはＳｉやＭｎと同様、高強度を得るのに有用な元素で
ある。しかしながら、過剰に添加すると脆化し易くなり
プレス加工性に悪影響を及ぼすため、その上限を0.10％
とすることが好ましい。特に軟鋼板の場合には、0.020
％以下とすることが好ましく、より好ましくは0.015 ％
以下である。P ≦ 0.10% P, like Si and Mn, is a useful element for obtaining high strength. However, if added excessively, it becomes brittle and adversely affects the press workability, so the upper limit is 0.10%
It is preferable that Especially in the case of mild steel, 0.020
% Or less, more preferably 0.015%
It is as follows.
【００３８】Ａｌ：0.005 〜0.10％ Ａｌは脱酸剤として有用な元素であり、その様な作用を
有効に発揮して鋼中のＯ量を低減するには0.005 ％以上
の添加が好ましい。しかしながら、過剰に添加してもそ
の効果が飽和するだけで無駄である他、酸化物系介在物
が増加して清浄度が低下し、伸びやプレス成形性の低下
を招くので、その上限を0.10％とすることが好ましい。Al: 0.005 to 0.10% Al is an element useful as a deoxidizing agent, and is preferably added in an amount of 0.005% or more to effectively exert such an effect and reduce the amount of O in steel. However, even if it is added excessively, the effect is only saturated and it is useless.In addition, the oxide inclusions increase and the cleanliness decreases, leading to a decrease in elongation and press formability. % Is preferable.
【００３９】Ｎ≦0.010 ％ Ｎは、過剰に添加すると時効が発生し、プレス加工時に
ストレッチャー・ストレインと呼ばれる表面不良を引き
起こすため、その上限を0.010 ％とすることが好まし
い。Ｎを固定するために鋼中にＴｉやＮｂを添加する場
合には、これら元素の歩留まりを向上してコストの低減
を図るために、その上限を0.0050％とすることが好まし
い。上記元素の他、必要に応じて以下の元素を添加して
も良い。N.ltoreq.0.010% If N is excessively added, aging occurs and a surface defect called a stretcher strain is caused at the time of press working. Therefore, the upper limit thereof is preferably set to 0.010%. When Ti or Nb is added to steel to fix N, the upper limit is preferably set to 0.0050% in order to improve the yield of these elements and reduce costs. In addition to the above elements, the following elements may be added as necessary.
【００４０】Ｔｉ：0.005 〜0.1 ％および／またはＮ
ｂ：0.005 〜0.1 ％ これらの元素は鋼中のＣやＮを析出固定して、プレス加
工性の向上に寄与する元素である。0.005 ％未満では、
この様な作用が有効に発揮されず、加工性や時効性が低
下するため、その下限を0.005 ％とすることが好まし
い。一方、0.1 ％を超えて添加してもその作用が飽和し
コストの上昇を招くだけである。Ti: 0.005 to 0.1% and / or N
b: 0.005 to 0.1% These elements are elements that precipitate and fix C and N in steel and contribute to improvement in press workability. Below 0.005%,
Since such an action is not effectively exerted and the workability and aging properties are reduced, the lower limit is preferably made 0.005%. On the other hand, the addition of more than 0.1% only saturates the effect and increases the cost.
【００４１】Ｂ：0.0005〜0.003 ％ Ｂは、プレス加工時および再加工時に発生する割れ（二
次加工脆性）を防止するのに有用な元素である。この様
な作用を有効に発揮させるためには、0.0005％以上の添
加が好ましい。しかしながら、0.003 ％を超えて添加し
てもその作用が飽和するだけでコスト上昇を招き不経済
であるので、その上限を0.003 ％とすることが好まし
い。B: 0.0005 to 0.003% B is an element useful for preventing cracks (secondary brittleness) generated during press working and rework. In order to effectively exert such an effect, it is preferable to add 0.0005% or more. However, even if it is added in excess of 0.003%, the effect is only saturated and the cost is increased, which is uneconomical. Therefore, it is preferable to set the upper limit to 0.003%.
【００４２】更に、Ｃｒ≦0.10％，Ｃａ≦0.010 ％，Ｃ
ｕ≦0.5 ％の範囲であれば、めっき外観性や加工性に対
して何等悪影響を及ぼすことがないので、必要に応じて
これらの元素を１種または２種以上添加しても良い。上
記の如く好ましい化学組成を有する鋼を用いてめっき原
板を製造するに当たり、好ましい要件を例示すると以下
の通りである。Further, Cr ≦ 0.10%, Ca ≦ 0.010%, C
If u ≦ 0.5%, there is no adverse effect on plating appearance and workability, so one or more of these elements may be added as necessary. Preferred requirements for producing a plating base sheet using steel having a preferred chemical composition as described above are as follows.
【００４３】本発明で用いられる鋼材は、連続鋳造後の
鋼片を用いてもよいし、あるいは直送圧延、熱片装入、
冷片からの再加熱圧延等を用いることも可能である。熱
間圧延における仕上温度はＡｒ3 点以上とすることが好
ましく、更に加工性を高めたい場合には、Ａｒ3 点直上
とすることが推奨される。The steel used in the present invention may be a steel slab after continuous casting, or may be directly rolled, charged with a hot slab,
It is also possible to use reheating rolling from cold pieces. The finishing temperature in the hot rolling is preferably set to the Ar 3 point or higher, and if it is desired to further enhance the workability, it is recommended to be set immediately above the Ar 3 point.
【００４４】巻取りまでの冷却速度は３０℃／ｓｅｃ以
上とすることが好ましく、更に加工性を高めたい場合に
は、７０℃／ｓｅｃ以上とすることが推奨される。巻取
温度は５００〜７５０℃の範囲とすることが好ましい。The cooling rate until winding is preferably 30 ° C./sec or more, and if it is desired to further enhance the workability, it is recommended to be 70 ° C./sec or more. The winding temperature is preferably in the range of 500 to 750 ° C.
【００４５】この様にして巻取られたコイルは、必要に
応じて酸洗、調質圧延、好ましくは５０％以上の冷間圧
延を施した後、焼鈍を行う。この焼鈍処理は、通常の箱
焼鈍および連続焼鈍のいずれでも良く、該焼鈍温度は再
結晶温度以上とすることが好ましい。通常は、箱焼鈍：
６００〜７５０℃、連続焼鈍：７５０〜９００℃とする
ことが推奨される。なお、いずれの焼鈍処理において
も、焼鈍後のフェライト結晶粒径があまり大きいと亜鉛
めっき結晶の成長性に悪影響を及ぼしてめっき表面の外
観を損なう恐れがあるため、焼鈍後のフェライト結晶粒
度をＪＩＳ測定法の７番以上の細粒とすることが好まし
い。The coil wound in this manner is subjected to pickling, temper rolling, preferably cold rolling of 50% or more, if necessary, and then annealing. This annealing treatment may be either normal box annealing or continuous annealing, and the annealing temperature is preferably equal to or higher than the recrystallization temperature. Usually, box annealing:
600-750 ° C, continuous annealing: 750-900 ° C is recommended. In any of the annealing treatments, if the ferrite crystal grain size after annealing is too large, the growth of zinc-plated crystals may be adversely affected and the appearance of the plating surface may be impaired. It is preferable to use fine particles of No. 7 or more in the measurement method.
【００４６】この様にして焼鈍されたコイルに、必要に
応じて調質圧延を施した後、電気亜鉛めっき処理を施
す。めっき前処理としては、通常の脱脂→水洗→酸洗処
理を行うことが好ましく、これらの処理条件については
特に制御されない。また、電気めっきの種類としても特
に限定されず、亜鉛めっきの他、亜鉛−鉄、亜鉛−ニッ
ケル等の合金めっきが挙げられる。この様にして得られ
ためっき層表面に、耐食性、塗装性、耐指紋性、潤滑性
等の向上を目的として、必要に応じてクロメート皮膜、
リン酸塩皮膜、有機樹脂被皮膜等を施しても良い。これ
ら皮膜の被覆処理については特に限定されず、通常の方
法を適宜採用し得る。これらの皮膜は、めっき層表面に
単層または複合層に積層される。このうち耐食性等の観
点から特に好ましいのは、めっき層表面にクロメート皮
膜および有機樹脂皮膜が順次施された電気亜鉛めっき鋼
板である。電気めっき後のコイルは、必要に応じて調質
圧延を行った後、所定の形状に成形される。The coil annealed in this manner is subjected to temper rolling if necessary, and then subjected to electrogalvanizing. As the pretreatment for plating, it is preferable to perform ordinary degreasing → water washing → pickling treatment, and these treatment conditions are not particularly controlled. Further, the type of electroplating is not particularly limited, and alloy plating of zinc-iron, zinc-nickel, or the like can be used in addition to zinc plating. On the plating layer surface thus obtained, a chromate film, if necessary, for the purpose of improving corrosion resistance, paintability, fingerprint resistance, lubricity, etc.
A phosphate film, an organic resin film or the like may be applied. The coating treatment of these films is not particularly limited, and a usual method can be appropriately adopted. These films are laminated on the surface of the plating layer as a single layer or a composite layer. Among them, an electrogalvanized steel sheet in which a chromate film and an organic resin film are sequentially applied to the surface of a plating layer is particularly preferable from the viewpoint of corrosion resistance and the like. The coil after electroplating is subjected to temper rolling as required, and then formed into a predetermined shape.
【００４７】以下実施例を挙げて本発明をさらに詳細に
説明するが、下記実施例は本発明を制限するものではな
く、前・後記の趣旨を逸脱しない範囲で変更実施するこ
とは全て本発明の技術的範囲に包含される。Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples do not limit the present invention, and all changes and implementations without departing from the spirit of the present invention will be described. Within the technical scope of
【００４８】[0048]
実施例１：化学成分組成の影響（１） 表１に示す化学成分組成を有する鋼（Ｎo.Ａ〜Ｐ）を実
験室規模で溶製して３０ｍｍ厚さのスラブとした後、熱
間圧延、冷間圧延、焼鈍、電気亜鉛めっき処理を順次施
すことにより電気亜鉛めっき鋼板を得た。詳細には、加
熱抽出温度：１１５０℃×１時間、仕上温度：８５０〜
９５０℃にて３．６ｍｍ厚さに仕上げた後、冷却速度：
７０℃／ｓｅｃにて冷却、５００℃×１時間の巻取処理
を施すことにより熱延鋼板を得た。なお、一部の材料
（Ｎo.Ｇ〜Ｉ）については、６８０℃×１時間の巻取処
理を行った。この様にして得られた熱延板を酸洗後、７
８％の圧下率にて冷間圧延を行うことにより０．８ｍｍ
厚の冷延鋼板を得た。次に、６５０℃×２０時間の箱焼
鈍、０．５％の調質圧延（但し、Ｎo.Ｇ〜Ｉについては
８００℃×１分間の連続焼鈍、０．５％の調質圧延）を
行った後、水洗、脱脂、硫酸水溶液酸洗の後、電気亜鉛
めっき、クロメート処理、有機樹脂被覆処理を順次行う
ことにより、めっき付着量が２０／２０／ｍ2 である電
気亜鉛めっき鋼板を得た。Example 1 Influence of Chemical Composition (1) Steel (No. AP) having the chemical composition shown in Table 1 was melted on a laboratory scale to form a slab having a thickness of 30 mm, and then hot-rolled. , Cold rolling, annealing and electrogalvanizing were sequentially performed to obtain an electrogalvanized steel sheet. Specifically, the heat extraction temperature: 1150 ° C. × 1 hour, the finishing temperature: 850 to
After finishing to a thickness of 3.6 mm at 950 ° C., the cooling rate is:
A hot rolled steel sheet was obtained by cooling at 70 ° C./sec and performing a winding treatment at 500 ° C. × 1 hour. Some of the materials (Nos. G to I) were subjected to a winding process at 680 ° C. × 1 hour. After pickling the hot rolled sheet thus obtained, 7
0.8mm by cold rolling at a rolling reduction of 8%
A thick cold-rolled steel sheet was obtained. Next, box annealing at 650 ° C. × 20 hours, temper rolling of 0.5% (however, for No.GI, continuous annealing at 800 ° C. × 1 minute, temper rolling of 0.5%) is performed. After that, washing with water, degreasing, and pickling with an aqueous sulfuric acid solution were performed, followed by electrogalvanizing, chromate treatment, and organic resin coating treatment, thereby obtaining an electrogalvanized steel sheet having a coating weight of 20/20 / m 2 . .
【００４９】この様にして得られた各種電気亜鉛めっき
鋼板について、ＪＩＳ ５号に記載の方法に準じて引張
特性［降伏強度（ＹＰ）、引張強度（ＴＳ）、伸び（Ｅ
ｌ）］、めっき外観性および木目状疵の発生率を評価し
た。なお、めっき外観および木目状疵の発生率は前述と
同様にして評価した。その結果を表２に示す。With respect to the various electrogalvanized steel sheets thus obtained, tensile properties [yield strength (YP), tensile strength (TS), elongation (E) were measured in accordance with the method described in JIS No. 5.
l)], the plating appearance and the occurrence rate of grain defects were evaluated. The plating appearance and the incidence of grain-like flaws were evaluated in the same manner as described above. Table 2 shows the results.
【００５０】[0050]
【表１】 [Table 1]
【００５１】[0051]
【表２】 [Table 2]
【００５２】これらの結果から、下記の様に考察するこ
とができる。Ｎｉ量が本発明の要件を満足するＮo.Ａ〜
Ｏは、いずれも木目状疵の発生率が目標値である１０％
以下に制御されている。このうち、Ｎｉ以外の他の元素
が本発明の好ましい要件を満足するＮo.Ａ〜Ｉは、引張
強度の程度によらず低降伏強度および高伸びを有すると
共に、加工性やめっき外観も良好であり、非常に優れた
電気亜鉛めっき鋼板であることがわかった。これに対し
て、Ｎｉ量が本発明で規定する上限を超える鋼Ｎo.Ｏ
は、木目状疵の発生率が非常に高くなった。From these results, the following can be considered. No. A to satisfy the requirements of the present invention.
O is 10%, which is the target value for the occurrence rate of grain defects
It is controlled as follows. Among them, Nos. A to I, in which elements other than Ni satisfy the preferred requirements of the present invention, have low yield strength and high elongation regardless of the degree of tensile strength, and also have good workability and plating appearance. It was found to be a very excellent electrogalvanized steel sheet. On the other hand, the steel No. O whose Ni content exceeds the upper limit specified in the present invention.
Has a very high incidence of grain defects.
【００５３】実施例２：加熱抽出温度の影響（１） 表１において本発明の要件を満足する鋼種Ａを用いて、
熱間圧延時における加熱抽出温度の影響を調べた。即
ち、上記スラブを１０５０〜１３００℃×１時間加熱抽
出した後、実施例１と同様にして処理することにより電
気亜鉛めっき鋼板を得た。この様にして得られためっき
鋼板について、実施例１と同様にして引張特性や木目状
疵等を測定すると共に、深絞り性（ｒ値）を測定した。
なお、ｒ値の算出は下記の様にして行った。 ｒ値＝（ｒL ＋ｒN ＋２ｒC ）／４ 式中、ｒL ，ｒN ，ｒC はそれぞれ、圧延方向、圧延直
角方向、４５度方向のｒ値を示す。この様にして得られ
た結果を表３に示す。Example 2 Effect of Heat Extraction Temperature (1) In Table 1, using steel type A satisfying the requirements of the present invention,
The effect of the hot extraction temperature during hot rolling was investigated. That is, the slab was heat-extracted at 1050 to 1300 ° C. for 1 hour and then treated in the same manner as in Example 1 to obtain an electrogalvanized steel sheet. With respect to the plated steel sheet thus obtained, the tensile properties, grain defects, and the like were measured in the same manner as in Example 1, and the deep drawability (r value) was measured.
The calculation of the r value was performed as follows. r value = (r L + r N + 2r C ) / 4 In the formula, r L , r N , and r C indicate r values in the rolling direction, the direction perpendicular to the rolling direction, and the 45-degree direction, respectively. Table 3 shows the results thus obtained.
【００５４】[0054]
【表３】 [Table 3]
【００５５】表の結果から明らかな様に、本発明で規定
する加熱抽出温度を満足するＮo.Ａ１〜Ａ４はいずれ
も、引張特性、深絞り性、めっき外観および木目状疵の
発生率が全て良好な電気亜鉛めっき鋼板であることが分
かった。これに対して、加熱抽出温度が本発明の要件を
満足しないＮo.Ａ５およびＡ６は、木目状疵の発生率が
目標値である１０％を大きく上回り、めっき外観も非常
に悪いものであった。As is evident from the results in the table, all of Nos. A1 to A4 satisfying the heat extraction temperature specified in the present invention have all of tensile properties, deep drawability, plating appearance and grain flaw occurrence rate. It turned out to be a good electrogalvanized steel sheet. On the other hand, in Nos. A5 and A6, in which the heat extraction temperature did not satisfy the requirements of the present invention, the occurrence rate of grain-like flaws greatly exceeded the target value of 10%, and the plating appearance was very poor. .
【００５６】実施例３：実機製造レベルでの評価（１） 表１の鋼種Ａを転炉にて溶製し、連続鋳造により２３０
ｍｍ厚のスラブとした後、加熱抽出温度を１１５０℃と
１３００℃の２通りの方法で処理した。次に、仕上温度
９２０℃にて３．８ｍｍ厚の熱延鋼板とした後、平均冷
却速度：９０℃／ｓｅｃで冷却し、５００℃にて巻取っ
たコイルを酸洗した後、冷間圧延にて０．８ｍｍ厚に仕
上げた。その後、６８０℃×２４時間の均熱箱焼鈍、
０．５％の調質圧延を行った後、実施例１と同様に処理
することにより電気亜鉛めっき鋼板を得た。この様にし
て得られためっき鋼板について、実施例２と同様にして
機械的性質や木目状疵発生率等を測定した。その結果を
表４に示す。Example 3 Evaluation at Production Level of Actual Machine (1) Steel type A shown in Table 1 was melted in a converter and subjected to continuous casting to 230
After the slab was formed into a slab having a thickness of mm, the slab was treated in two different ways at a heating extraction temperature of 1150 ° C. and 1300 ° C. Next, a hot-rolled steel sheet having a thickness of 3.8 mm was formed at a finishing temperature of 920 ° C., cooled at an average cooling rate of 90 ° C./sec, and the coil wound at 500 ° C. was pickled and then cold-rolled. To a thickness of 0.8 mm. After that, soaking box annealing at 680 ° C for 24 hours,
After performing a temper rolling of 0.5%, an electrogalvanized steel sheet was obtained by performing the same treatment as in Example 1. For the plated steel sheet thus obtained, the mechanical properties, the grain-like flaw occurrence rate, and the like were measured in the same manner as in Example 2. Table 4 shows the results.
【００５７】[0057]
【表４】 [Table 4]
【００５８】表の結果から明らかな様に、本発明の要件
をすべて満足するＮo.Ｘは、木目状疵の発生率が低く、
その他の諸特性もすべて良好であることから、実操業レ
ベルでも、この様な電気亜鉛めっき鋼板を製造できるこ
とがことが分かった。これに対して、加熱抽出温度が本
発明の要件を満足しないＮo.Ｙは、木目状疵の発生率が
非常に高く、めっき外観性に劣っていた。As is clear from the results in the table, No. X, which satisfies all the requirements of the present invention, has a low incidence of grain-like defects,
Since all other properties were also good, it was found that such an electrogalvanized steel sheet could be manufactured even at the actual operation level. On the other hand, No. Y, whose heating extraction temperature did not satisfy the requirements of the present invention, had a very high occurrence rate of grain defects and was poor in plating appearance.
【００５９】実施例４：化学成分組成の影響（２） 表５に示す化学成分組成を有する鋼（Ｎo.Ａ〜Ｐ）を実
験室規模で溶製して３０ｍｍ厚のスラブとした後、熱間
圧延、冷間圧延、焼鈍、電気亜鉛めっき処理を順次施す
ことにより電気亜鉛めっき鋼板を得た。詳細には、加熱
抽出温度：１１５０℃×１時間、仕上温度：９２０〜９
５０℃にて３．６ｍｍ厚さに仕上げた後、冷却速度：７
０℃／ｓｅｃにて冷却、６８０℃×１時間の巻取処理を
施すことにより熱延鋼板を得た。この様にして得られた
熱延板を酸洗後、７８％の圧下率にて冷間圧延を行うこ
とにより０．８ｍｍ厚の冷延鋼板を得た。次に、８００
℃×１分の連続焼鈍、０．５％の調質圧延を行った後、
脱脂、塩酸水溶液酸洗を施し、更に電気亜鉛めっき、ク
ロメート処理、有機樹脂被覆処理を順次行うことによ
り、めっき付着量が２０／２０／ｍ2 である電気亜鉛め
っき鋼板を得た。[0059] Example 4: After a 30mm thick slab was melted influence of chemical composition (2) Steel having the chemical compositions shown in Table 5 (No.A～ P) on a laboratory scale, the heat An electrogalvanized steel sheet was obtained by sequentially performing cold rolling, cold rolling, annealing and electrogalvanizing. Specifically, heat extraction temperature: 1150 ° C. × 1 hour, finishing temperature: 920 to 9
After finishing to a thickness of 3.6 mm at 50 ° C., cooling rate: 7
A hot-rolled steel sheet was obtained by performing cooling at 0 ° C./sec and winding at 680 ° C. × 1 hour. The hot rolled sheet thus obtained was pickled and then cold rolled at a rolling reduction of 78% to obtain a 0.8 mm thick cold rolled steel sheet. Next, 800
After continuous annealing at ℃ × 1 minute and temper rolling of 0.5%,
By performing degreasing, pickling with an aqueous solution of hydrochloric acid, and subsequently performing electrogalvanizing, chromate treatment, and organic resin coating, an electrogalvanized steel sheet having a coating weight of 20/20 / m 2 was obtained.
【００６０】この様にして得られた各種電気亜鉛めっき
鋼板について、実施例２と同様にして引張特性［ＹＰ，
ＴＳ，Ｅｌの他、張出し性（ｎ値）もＪＩＳ ５号に準
じて測定した］、めっき外観性および木目状疵の発生率
を測定した。その結果を表６に示す。With respect to the various electrogalvanized steel sheets thus obtained, the tensile properties [YP,
In addition to TS and El, the overhang property (n value) was also measured according to JIS No. 5], the plating appearance, and the occurrence rate of grain defects were measured. Table 6 shows the results.
【００６１】[0061]
【表５】 [Table 5]
【００６２】[0062]
【表６】 [Table 6]
【００６３】これらの結果から、下記の様に考察するこ
とができる。Ｎｉ量が本発明の要件を満足するＮo.Ａ〜
ＭおよびＯ，Ｐは、いずれも木目状疵の発生率が目標値
である１０％以下に制御されている。このうち、Ｎｉ以
外の他の元素が本発明の好ましい要件を満足するＮo.Ａ
〜Ｉは、引張強度の程度によらず低降伏強度、高伸び、
および高張出し性を有すると共に、加工性やめっき外観
も良好であり、非常に優れた電気亜鉛めっき鋼板である
ことがわかった。これに対して、Ｎｉ量が本発明で規定
する上限を超えるＮo.Ｎは、木目状疵の発生率が非常に
高くなった。From these results, the following can be considered. No. A to satisfy the requirements of the present invention.
M, O, and P are all controlled such that the occurrence rate of grain defects is 10% or less, which is the target value. Among them, elements other than Ni satisfy the preferable requirements of the present invention.
~ I is low yield strength, high elongation regardless of the degree of tensile strength,
In addition to having high overhang property, the workability and the plating appearance were also good, and it was found that the electrogalvanized steel sheet was very excellent. On the other hand, in the case of No. N in which the amount of Ni exceeds the upper limit specified in the present invention, the occurrence rate of grain defects was extremely high.
【００６４】実施例５：加熱抽出温度の影響（２） 表５に記載の本発明鋼種Ａを用いて、熱間圧延時におけ
る加熱抽出温度の影響を調べた。即ち、上記スラブを１
０５０〜１３００℃×１時間加熱抽出した後、実施例１
と同様にして処理することにより電気亜鉛めっき鋼板を
得た。この様にして得られためっき鋼板について、実施
例４と同様にして引張特性等の機械的性質、木目状疵等
を測定した。得られた結果を表７に示す。Example 5 Influence of Heat Extraction Temperature (2) Using the steel type A of the present invention shown in Table 5, the influence of the heat extraction temperature during hot rolling was examined. That is, 1
Example 1 After heating and extracting at 050-1300 ° C. × 1 hour,
In the same manner as described above, an electrogalvanized steel sheet was obtained. With respect to the plated steel sheet thus obtained, mechanical properties such as tensile properties, grain-like flaws and the like were measured in the same manner as in Example 4. Table 7 shows the obtained results.
【００６５】[0065]
【表７】 [Table 7]
【００６６】表の結果から明らかな様に、本発明で規定
する加熱抽出温度を満足するＮo.Ａ１〜Ａ４はいずれ
も、引張特性、深絞り性、めっき外観、木目状疵の発生
率がすべて良好な電気亜鉛めっき鋼板であった。これに
対して、加熱抽出温度が本発明の要件を満足しないＮo.
Ａ５およびＡ６は、木目状疵の発生率が目標値である１
０％を大きく上回り、めっき外観も非常に悪いものであ
った。As is evident from the results in the table, all of Nos. A1 to A4 satisfying the heating extraction temperature specified in the present invention have all of tensile properties, deep drawability, plating appearance, and occurrence rate of wood grain defects. It was a good electrogalvanized steel sheet. On the other hand, when the heating extraction temperature does not satisfy the requirements of the present invention, No.
A5 and A6 are 1 in which the occurrence rate of wood grain defects is the target value.
It greatly exceeded 0%, and the plating appearance was very poor.
【００６７】実施例６：実機製造レベルでの評価（２） 表５の鋼種Ａを転炉にて溶製し、連続鋳造により２３０
ｍｍ厚のスラブとした後、加熱抽出温度を１１５０℃と
１３００℃の２通りの方法で処理した。次に、仕上温度
９２０℃にて３．８ｍｍ厚の熱延鋼板とした後、平均冷
却速度：９０℃／ｓｅｃで冷却し、６８０℃にて巻取っ
たコイルを酸洗した後、冷間圧延にて０．８ｍｍ厚に仕
上げた。その後、８００℃×１分間の連続焼鈍、０．５
％の調質圧延を行った後、実施例５と同様に処理するこ
とにより電気亜鉛めっき鋼板を得た。この様にして得ら
れためっき鋼板について、実施例４と同様にして機械的
性質や木目状疵発生率等を測定した。その結果を表８に
示す。Example 6: Evaluation at actual production level (2) Steel type A shown in Table 5 was melted in a converter and subjected to continuous casting by 230.
After the slab was formed into a slab having a thickness of mm, the slab was treated in two different ways at a heating extraction temperature of 1150 ° C. and 1300 ° C. Next, after a hot-rolled steel sheet having a thickness of 3.8 mm was formed at a finishing temperature of 920 ° C., the coil was cooled at an average cooling rate of 90 ° C./sec, pickled at 680 ° C., and then cold-rolled. To a thickness of 0.8 mm. Thereafter, continuous annealing at 800 ° C. for 1 minute, 0.5
%, And then processed in the same manner as in Example 5 to obtain an electrogalvanized steel sheet. For the plated steel sheet thus obtained, the mechanical properties, the grain-like flaw occurrence rate, and the like were measured in the same manner as in Example 4. Table 8 shows the results.
【００６８】[0068]
【表８】 [Table 8]
【００６９】表の結果から明らかな様に、本発明の要件
をすべて満足するＮo.Ｘを用いると、木目状疵の発生率
が低く、その他の諸特性もすべて良好な電気亜鉛めっき
鋼板を、実操業レベルでも製造できることが分かった。
これに対して、加熱抽出温度が本発明の要件を満足しな
いＮo.Ｙの場合は、木目状疵の発生率が非常に高く、め
っき外観性に劣ることが分かった。As is clear from the results in the table, when No. X that satisfies all of the requirements of the present invention is used, an electrogalvanized steel sheet having a low occurrence rate of grain defects and having all other favorable properties can be obtained. It turned out that it can be manufactured even at the actual operation level.
On the other hand, when the heating extraction temperature was No. Y which did not satisfy the requirements of the present invention, the occurrence rate of wood grain flaws was extremely high and the plating appearance was poor.
【００７０】[0070]
【発明の効果】本発明の電気亜鉛めっき用鋼板は以上の
様に構成されているので、木目状疵の発生率が極めて少
なく表面性状に優れた電気亜鉛めっき鋼板を得る為のめ
っき原板として非常に有用であることが分かった。ま
た、本発明の電気亜鉛めっき用鋼板の製造方法は、この
様な鋼板を効率よく製造することのできる方法である。
本発明の製造方法において、更にＮｉ以外の他の元素を
制御すれば、加工性等も良好な電気亜鉛めっき鋼板を得
ることができる。Since the steel sheet for electrogalvanizing of the present invention is constituted as described above, it is very useful as a base sheet for obtaining an electrogalvanized steel sheet having an extremely low grain-like flaw occurrence rate and excellent surface properties. Was found to be useful. The method for producing a steel sheet for electrogalvanizing according to the present invention is a method capable of efficiently producing such a steel sheet.
In the production method of the present invention, by further controlling elements other than Ni, an electrogalvanized steel sheet having good workability and the like can be obtained.
【図１】Ｔｉ非添加鋼における、木目状疵の発生率と鋼
中Ｎｉ量の関係を示すグラフである。FIG. 1 is a graph showing the relationship between the incidence of grain-like flaws and the amount of Ni in steel in Ti-free steel.
【図２】Ｔｉ非添加鋼における、木目状疵の発生率と加
熱抽出温度の関係を示すグラフである。FIG. 2 is a graph showing the relationship between the rate of occurrence of wood grain defects and the heat extraction temperature in Ti-free steel.
【図３】Ｔｉ非添加鋼における、Ｎｉ濃化曲線を示すグ
ラフである。FIG. 3 is a graph showing a Ni concentration curve in a steel not containing Ti.
【図４】Ｔｉ非添加鋼における、鋼板表層部のＮｉ濃度
とめっき表面外観との関係を示すグラフである。FIG. 4 is a graph showing the relationship between the Ni concentration in the surface layer of a steel sheet and the appearance of a plated surface in a steel not containing Ti.
【図５】Ｔｉ非添加鋼における、Ｎｉ濃度が４原子％以
下になる深さと、めっき表面外観性の関係を示すグラフ
である。FIG. 5 is a graph showing the relationship between the depth at which the Ni concentration becomes 4 atom% or less and the plating surface appearance in a steel not containing Ti.
【図６】Ｔｉ添加鋼における、木目状疵の発生率と鋼中
Ｎｉ量の関係を示すグラフである。FIG. 6 is a graph showing the relationship between the incidence of grain-like flaws and the amount of Ni in steel in Ti-added steel.
【図７】Ｔｉ添加鋼における、木目状疵の発生率と加熱
抽出温度の関係を示すグラフである。FIG. 7 is a graph showing the relationship between the incidence of wood grain defects and the heat extraction temperature in Ti-added steel.
【図８】Ｔｉ添加鋼における、Ｎｉ濃化曲線を示すグラ
フである。FIG. 8 is a graph showing a Ni concentration curve in a Ti-added steel.
【図９】Ｔｉ添加鋼における、鋼板表層部のＮｉ濃度と
めっき表面外観との関係を示すグラフである。FIG. 9 is a graph showing the relationship between the Ni concentration of the steel sheet surface layer and the plating surface appearance in the Ti-added steel.
【図１０】Ｔｉ添加鋼における、Ｎｉ濃度が４原子％以
下になる深さと、めっき表面外観の関係を示すグラフで
ある。FIG. 10 is a graph showing the relationship between the depth at which the Ni concentration becomes 4 atomic% or less and the plating surface appearance in the Ti-added steel.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 ＦＩ Ｃ２５Ｄ 5/26 Ｃ２５Ｄ 5/26 Ｃ (72)発明者 三木 政一 兵庫県加古川市金沢町１番地 株式会社 神戸製鋼所 加古川製鉄所内 (72)発明者 石丸 誠 兵庫県加古川市金沢町１番地 株式会社 神戸製鋼所 加古川製鉄所内 (72)発明者 梅井 健司 兵庫県加古川市金沢町１番地 株式会社 神戸製鋼所 加古川製鉄所内 (58)調査した分野(Int.Cl.6，ＤＢ名) C22C 38/00 - 38/60 B32B 15/08 C21D 9/46 C23C 28/00 C25D 5/26 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 6 Identification code FI C25D 5/26 C25D 5/26 C (72) Inventor Seiichi Miki 1 Kanazawacho, Kakogawa City, Hyogo Prefecture Kobe Steel, Ltd. Kakogawa Works In-house (72) Inventor Makoto Ishimaru 1 Kanazawa-cho, Kakogawa-shi, Hyogo Prefecture Kobe Steel, Ltd. Field surveyed (Int.Cl. 6 , DB name) C22C 38/00-38/60 B32B 15/08 C21D 9/46 C23C 28/00 C25D 5/26
Claims (10)
味、以下同じ）に制限すると共に、鋼板表層部のＮｉ濃
度が１０原子％以下であって且つ鋼板表面から２００Å
の深さ位置におけるＮｉ濃度が４原子％以下であること
を特徴とする耐木目状疵性に優れた電気亜鉛めっき用鋼
板。(1) The amount of Ni in steel is limited to 0.06% or less (meaning by weight, the same applies hereinafter), the Ni concentration in the surface layer of the steel sheet is 10 atomic% or less, and 200% from the steel sheet surface.
A Ni concentration at a depth of 4 atomic% or less.
１に記載の電気亜鉛めっき用鋼板。2. The steel sheet for electrogalvanizing according to claim 1, wherein the amount of Ni in the steel is 0.03% or less.
き用鋼板に電気亜鉛めっきが施されたものであることを
特徴とする電気亜鉛めっき鋼板。3. An electrogalvanized steel sheet wherein the electrogalvanized steel sheet according to claim 1 or 2 is electrogalvanized.
よび有機樹脂皮膜が順次施されたものである請求項３に
記載の電気亜鉛めっき鋼板。4. The galvanized steel sheet according to claim 3, wherein a chromate film and an organic resin film are sequentially applied on the surface of the plating layer.
求項１または２に記載の電気亜鉛めっき用鋼板。5. The steel sheet for electrogalvanizing according to claim 1, which is used as an outer sheet material for an electric product.
求項３または４に記載の電気亜鉛めっき鋼板。6. The galvanized steel sheet according to claim 3, which is used as an outer plate material for an electric product.
用し、 熱間圧延における鋼材の表面温度を１２００℃以下に抑
えると共に抽出温度を１０５０〜１２００℃に制御する
ことにより、 電気亜鉛めっき用鋼板表層部のＮｉ濃度を１０原子％以
下、および鋼板表面から２００Åの深さ位置におけるＮ
ｉ濃度を４原子％以下に抑制することを特徴とする耐木
目状疵性に優れた電気亜鉛めっき用鋼板の製造方法。7. Electrogalvanizing by using a steel material in which the amount of Ni is suppressed to 0.06% or less, and controlling the surface temperature of the steel material in hot rolling to 1200 ° C. or less and controlling the extraction temperature to 1050 to 1200 ° C. Ni concentration in the surface layer of the steel sheet for use is 10 atomic% or less and N at a depth of 200 ° from the steel sheet surface
A method for producing a steel sheet for electrogalvanizing excellent in grain resistance, characterized in that the i concentration is suppressed to 4 atomic% or less.
７に記載の製造方法。8. The method according to claim 7, wherein the amount of Ni in the steel is 0.03% or less.
≦1.8 ％，Ｐ≦0.10％，Ａｌ：0.005 〜0.10％，Ｎ≦0.
010 ％の要件を満たすものである請求項７または８に記
載の製造方法。9. The steel material is C ≦ 0.10%, Si ≦ 0.2%, Mn
≦ 1.8%, P ≦ 0.10%, Al: 0.005 to 0.10%, N ≦ 0.
9. The production method according to claim 7, which satisfies the requirement of 010%.
て得られた電気亜鉛めっき用鋼板に、電気亜鉛めっきを
施すことを特徴とする耐木目状疵性に優れた電気亜鉛め
っき鋼板の製造方法。10. Production of an electrogalvanized steel sheet having excellent grain resistance, wherein the galvanized steel sheet obtained by the method according to any one of claims 7 to 9 is electrogalvanized. Method.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7144989A JP2950199B2 (en) | 1995-06-12 | 1995-06-12 | Electrogalvanized steel sheet and electrogalvanized steel sheet having excellent wood grain resistance, and methods for producing them |
| KR1019960013701A KR100205190B1 (en) | 1995-06-12 | 1996-04-30 | Steel sheet for electrogalvanizing excellent in grained flow resistance trogalvanized steel sheet and their production |
| TW085106745A TW446761B (en) | 1995-06-12 | 1996-06-05 | A steel sheet for electrogalvanization and an electrogalvanized steel sheet with excellent black mark resistance, and a method for manufacturing them |
| CN96111048A CN1068069C (en) | 1995-06-12 | 1996-06-12 | Zinc plated steel plate with good anti-grainy defect and zinc plated steel plate and its producing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7144989A JP2950199B2 (en) | 1995-06-12 | 1995-06-12 | Electrogalvanized steel sheet and electrogalvanized steel sheet having excellent wood grain resistance, and methods for producing them |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08337842A JPH08337842A (en) | 1996-12-24 |
| JP2950199B2 true JP2950199B2 (en) | 1999-09-20 |
Family
ID=15374897
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7144989A Expired - Lifetime JP2950199B2 (en) | 1995-06-12 | 1995-06-12 | Electrogalvanized steel sheet and electrogalvanized steel sheet having excellent wood grain resistance, and methods for producing them |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP2950199B2 (en) |
| KR (1) | KR100205190B1 (en) |
| CN (1) | CN1068069C (en) |
| TW (1) | TW446761B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007039812A (en) * | 2006-10-06 | 2007-02-15 | Jfe Steel Kk | Steel sheet having excellent surface property |
| JP5723103B2 (en) * | 2009-03-27 | 2015-05-27 | 株式会社神戸製鋼所 | High thermal conductivity steel sheet |
| DE102009051673B3 (en) * | 2009-11-03 | 2011-04-14 | Voestalpine Stahl Gmbh | Production of galvannealed sheets by heat treatment of electrolytically finished sheets |
| JP5671438B2 (en) * | 2011-10-31 | 2015-02-18 | 株式会社神戸製鋼所 | High thermal conductivity steel plate |
| WO2016055227A1 (en) | 2014-10-09 | 2016-04-14 | Thyssenkrupp Steel Europe Ag | Cold-rolled and recrystallisation annealed flat steel product, and method for the production thereof |
| CN104480369A (en) * | 2014-12-09 | 2015-04-01 | 武汉钢铁(集团)公司 | Electro-galvanized sheet for liquid crystal module and preparation method of electro-galvanized sheet |
| JP6897882B2 (en) * | 2018-10-19 | 2021-07-07 | 日本製鉄株式会社 | Hot-rolled steel sheet and its manufacturing method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5317533A (en) * | 1976-07-31 | 1978-02-17 | Nippon Steel Corp | Production method of electrootin plate |
-
1995
- 1995-06-12 JP JP7144989A patent/JP2950199B2/en not_active Expired - Lifetime
-
1996
- 1996-04-30 KR KR1019960013701A patent/KR100205190B1/en not_active IP Right Cessation
- 1996-06-05 TW TW085106745A patent/TW446761B/en not_active IP Right Cessation
- 1996-06-12 CN CN96111048A patent/CN1068069C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| KR100205190B1 (en) | 1999-07-01 |
| JPH08337842A (en) | 1996-12-24 |
| CN1068069C (en) | 2001-07-04 |
| CN1156185A (en) | 1997-08-06 |
| TW446761B (en) | 2001-07-21 |
| KR970001595A (en) | 1997-01-24 |
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