USRE45821E1 - Zinc-based metal plated steel sheet - Google Patents
Zinc-based metal plated steel sheet Download PDFInfo
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- USRE45821E1 USRE45821E1 US14/319,298 US200814319298A USRE45821E US RE45821 E1 USRE45821 E1 US RE45821E1 US 200814319298 A US200814319298 A US 200814319298A US RE45821 E USRE45821 E US RE45821E
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- United States
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- steel sheet
- znso
- oxide layer
- zinc
- based metal
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 97
- 239000010959 steel Substances 0.000 title claims abstract description 97
- 239000011701 zinc Substances 0.000 title abstract description 33
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 title abstract description 23
- 229910052725 zinc Inorganic materials 0.000 title abstract description 22
- 239000002184 metal Substances 0.000 title abstract description 19
- 229910052751 metal Inorganic materials 0.000 title abstract description 19
- 229910000368 zinc sulfate Inorganic materials 0.000 claims abstract description 40
- NWONKYPBYAMBJT-UHFFFAOYSA-L zinc sulfate Chemical compound [Zn+2].[O-]S([O-])(=O)=O NWONKYPBYAMBJT-UHFFFAOYSA-L 0.000 claims abstract description 38
- 239000011686 zinc sulphate Substances 0.000 claims abstract description 38
- 229910009112 xH2O Inorganic materials 0.000 claims abstract description 5
- 238000007747 plating Methods 0.000 claims description 27
- 239000010410 layer Substances 0.000 description 42
- 239000010408 film Substances 0.000 description 38
- 238000011282 treatment Methods 0.000 description 27
- 238000000034 method Methods 0.000 description 22
- 230000000052 comparative effect Effects 0.000 description 19
- 230000003647 oxidation Effects 0.000 description 19
- 238000007254 oxidation reaction Methods 0.000 description 19
- 239000011324 bead Substances 0.000 description 15
- 238000012360 testing method Methods 0.000 description 14
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 12
- 229910001335 Galvanized steel Inorganic materials 0.000 description 11
- 239000008397 galvanized steel Substances 0.000 description 11
- 239000000243 solution Substances 0.000 description 10
- 239000011248 coating agent Substances 0.000 description 9
- 238000000576 coating method Methods 0.000 description 9
- 238000005259 measurement Methods 0.000 description 9
- 239000003921 oil Substances 0.000 description 9
- 230000000694 effects Effects 0.000 description 8
- 238000003825 pressing Methods 0.000 description 7
- 230000009467 reduction Effects 0.000 description 7
- RZLVQBNCHSJZPX-UHFFFAOYSA-L zinc sulfate heptahydrate Chemical compound O.O.O.O.O.O.O.[Zn+2].[O-]S([O-])(=O)=O RZLVQBNCHSJZPX-UHFFFAOYSA-L 0.000 description 7
- 239000007864 aqueous solution Substances 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 239000007788 liquid Substances 0.000 description 5
- 238000005096 rolling process Methods 0.000 description 5
- 239000002344 surface layer Substances 0.000 description 5
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- 239000000314 lubricant Substances 0.000 description 4
- XIOUDVJTOYVRTB-UHFFFAOYSA-N 1-(1-adamantyl)-3-aminothiourea Chemical compound C1C(C2)CC3CC2CC1(NC(=S)NN)C3 XIOUDVJTOYVRTB-UHFFFAOYSA-N 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 229910001297 Zn alloy Inorganic materials 0.000 description 3
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 239000010960 cold rolled steel Substances 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000005244 galvannealing Methods 0.000 description 3
- 238000000227 grinding Methods 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 229910052814 silicon oxide Inorganic materials 0.000 description 3
- 239000010409 thin film Substances 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- 101000993059 Homo sapiens Hereditary hemochromatosis protein Proteins 0.000 description 2
- VMHLLURERBWHNL-UHFFFAOYSA-M Sodium acetate Chemical compound [Na+].CC([O-])=O VMHLLURERBWHNL-UHFFFAOYSA-M 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000003929 acidic solution Substances 0.000 description 2
- 238000005275 alloying Methods 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 239000011790 ferrous sulphate Substances 0.000 description 2
- 235000003891 ferrous sulphate Nutrition 0.000 description 2
- 238000005246 galvanizing Methods 0.000 description 2
- 150000004688 heptahydrates Chemical class 0.000 description 2
- 238000007654 immersion Methods 0.000 description 2
- 230000001771 impaired effect Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- SURQXAFEQWPFPV-UHFFFAOYSA-L iron(2+) sulfate heptahydrate Chemical compound O.O.O.O.O.O.O.[Fe+2].[O-]S([O-])(=O)=O SURQXAFEQWPFPV-UHFFFAOYSA-L 0.000 description 2
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 150000004686 pentahydrates Chemical class 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000001632 sodium acetate Substances 0.000 description 2
- 235000017281 sodium acetate Nutrition 0.000 description 2
- 150000004685 tetrahydrates Chemical class 0.000 description 2
- 150000004684 trihydrates Chemical class 0.000 description 2
- 229960001763 zinc sulfate Drugs 0.000 description 2
- IIEJGTQVBJHMDL-UHFFFAOYSA-N 2-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]-5-[2-oxo-2-[3-(sulfamoylamino)pyrrolidin-1-yl]ethyl]-1,3,4-oxadiazole Chemical compound C1CN(CC1NS(=O)(=O)N)C(=O)CC2=NN=C(O2)C3=CN=C(N=C3)NC4CC5=CC=CC=C5C4 IIEJGTQVBJHMDL-UHFFFAOYSA-N 0.000 description 1
- 229910000640 Fe alloy Inorganic materials 0.000 description 1
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 1
- NEAPKZHDYMQZCB-UHFFFAOYSA-N N-[2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]piperazin-1-yl]ethyl]-2-oxo-3H-1,3-benzoxazole-6-carboxamide Chemical compound C1CN(CCN1CCNC(=O)C2=CC3=C(C=C2)NC(=O)O3)C4=CN=C(N=C4)NC5CC6=CC=CC=C6C5 NEAPKZHDYMQZCB-UHFFFAOYSA-N 0.000 description 1
- NIPNSKYNPDTRPC-UHFFFAOYSA-N N-[2-oxo-2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 NIPNSKYNPDTRPC-UHFFFAOYSA-N 0.000 description 1
- AFCARXCZXQIEQB-UHFFFAOYSA-N N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CCNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 AFCARXCZXQIEQB-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910007542 Zn OH Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000011088 calibration curve Methods 0.000 description 1
- 238000003776 cleavage reaction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 238000005238 degreasing Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000007017 scission Effects 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000001488 sodium phosphate Substances 0.000 description 1
- 229910000162 sodium phosphate Inorganic materials 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- RYFMWSXOAZQYPI-UHFFFAOYSA-K trisodium phosphate Chemical compound [Na+].[Na+].[Na+].[O-]P([O-])([O-])=O RYFMWSXOAZQYPI-UHFFFAOYSA-K 0.000 description 1
- 238000004876 x-ray fluorescence Methods 0.000 description 1
Images
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
- C23C2/06—Zinc or cadmium or alloys based thereon
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- A61F13/51401—Backsheet, i.e. the impermeable cover or layer furthest from the skin characterised by the material
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
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- C—CHEMISTRY; METALLURGY
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- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
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- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/48—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 not containing phosphates, hexavalent chromium compounds, fluorides or complex fluorides, molybdates, tungstates, vanadates or oxalates
- C23C22/53—Treatment of zinc or alloys based thereon
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y10T428/12771—Transition metal-base component
- Y10T428/12785—Group IIB metal-base component
- Y10T428/12792—Zn-base component
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y10T428/00—Stock material or miscellaneous articles
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- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
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- Y10T428/12792—Zn-base component
- Y10T428/12799—Next to Fe-base component [e.g., galvanized]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/26—Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
- Y10T428/263—Coating layer not in excess of 5 mils thick or equivalent
- Y10T428/264—Up to 3 mils
- Y10T428/265—1 mil or less
Definitions
- This disclosure relates to a zinc-based metal plated steel sheet excellent in tribological property during press forming.
- Zinc-based metal plated steel sheets are widely used in many fields, in particular, for automobile bodies. When used for automobile bodies, they are subjected to press forming before use. Zinc-based metal plated steel sheets, however, have the disadvantage that their press formability is inferior to that of cold-rolled steel sheets. This is because in a press die, the friction resistance of a surface-treated steel sheet is larger than that of a cold-rolled steel sheet. That is, the surface-treated steel sheet does not smoothly flow into the die at a portion of the surface-treated steel sheet having a large friction resistance to the die and a bead. This is liable to cause rupture of the steel sheet.
- High-tensile steel sheets have press formability inferior to that of mild steel sheets.
- high-tensile steel sheets are easily ruptured at portions of high-tensile steel sheets having a large friction resistance to dies and beads.
- Galvannealed steel sheets are excellent in weldability and paintability compared with galvanized steel sheets and, thus, more preferably used for automobile bodies.
- a galvannealed steel sheet is produced as follows: a steel sheet is subjected to galvanizing and then heat treatment. As a result, an alloying reaction in which Fe in the steel sheet and Zn in a plating layer are diffused occurs, thereby forming a Fe—Zn alloy phase.
- the Fe—Zn alloy phase is in the form of a layer usually including a ⁇ phase, ⁇ 1 phase, and a ⁇ phase. Hardness and a melting point tend to decrease as the Fe concentration decreases, i.e., in a sequence of the ⁇ phase ⁇ the ⁇ 1 phase ⁇ the ⁇ phase.
- a high-hardness, high-melting point film with high Fe concentration is effective from the viewpoint of achieving good tribological properties because adhesion does not easily occur.
- Galvannealed steel sheets with the emphasis on press formability are produced in such a manner that average Fe concentrations in films are relatively high.
- Japanese Unexamined Patent Application Publication Nos. 53-60332 and 2-190483 each disclose a technique for improving weldability or processability by subjecting surfaces of a zinc-based metal plated steel sheet to electrolytic treatment, immersion treatment, coating and oxidation treatment, or heat treatment to form an oxide film mainly composed of ZnO.
- Japanese Unexamined Patent 4-88196 discloses a technique for improving press formability and chemical conversion treatability by immersing surfaces of a zinc-based metal plated steel sheet in an aqueous solution containing 5 to 60 g/L sodium phosphate and having a pH of 2 to 6, electrolytic treatment, or applying the solution described above to form an oxide film mainly composed of a P oxide.
- Japanese Unexamined Patent Application Publication No. 3-191093 discloses a technique for improving press formability and chemical conversion treatability by subjecting surfaces of a zinc-based metal plated steel sheet to electrolytic treatment, immersion treatment, coating, coating and oxidation treatment, or heat treatment to form a Ni oxide.
- Japanese Unexamined Patent Application Publication No. 2003-306781 discloses a technique for improving tribological properties by bringing a galvannealed steel sheet into contact with an acidic solution to form an oxide mainly composed of Zn on surfaces of the steel sheet and suppress adhesion between a plating layer and a press die.
- the technique for improving press formability by forming an oxide mainly composed of Zn on surfaces of steel sheet disclosed in Japanese Unexamined Patent Application Publication No. 2003-306781 and the like has the advantage over the technique using Ni and the like disclosed in Japanese Unexamined Patent Application Publication No. 3-191093 in production cost and environmental loading because Zn contained in the plated steel sheet is mainly used.
- a high degree of press formability is required, so that further improvement in tribological property may be required.
- FIG. 1 is a schematic front view of an apparatus for measuring a coefficient of friction.
- FIG. 2 is a schematic perspective view of the shape and dimensions of a bead shown in FIG. 1 .
- FIG. 3 is a schematic perspective view of the shape and dimensions of a bead shown in FIG. 1 .
- a flat portion on a surface of a galvannealed steel sheet is a portion with which a die comes into direct contact during press forming.
- the presence of a hard and high-melting-point material that prevents adhesion to the die is important in improving tribological properties.
- a hot-dip galvanized steel sheet and an electrogalvanized steel sheet which have surface irregularities smaller than those of the galvannealed steel sheet each of their surfaces is naturally a portion with which a die comes into direct contact during press forming.
- the presence of a hard and high-melting-point material in their surface layers is important for improving tribological properties.
- an oxide layer on a surface layer is effective in improving tribological properties.
- An oxide layer containing crystalline 3Zn(OH) 2 ⁇ ZnSO 4 ⁇ xH 2 O is very effective.
- an oxide layer containing crystalline 3Zn(OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O is significantly effective.
- Whether crystalline 3Zn(OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O is present in the oxide layer or not was determined by measuring an X-ray diffraction pattern of the oxide layer using X-ray diffractometry for a thin film and checking the resulting pattern against a standard pattern described in an ICDD card.
- a thickness of the oxide layer on the surface plating layer of 10 nm or more results in a zinc-based metal plated steel sheet having good tribological properties.
- a thickness of 20 nm or more is more effective. This is because the oxide layer remains even if the oxide layer on the surface layer is worn in press forming in which the contact area between a die and a workpiece is large, thus not leading to a reduction in tribological properties.
- the upper limit of the thickness is not set.
- a thickness exceeding 200 nm results in a reduction in etch rate with a chemical conversion treatment liquid even when the oxide layer has Zn—OH bonds, thus leading to difficulty in the formation of a dense, uniform chemical conversion film.
- the thickness is therefore desirably 200 nm or less.
- the most effective method for forming an oxide layer containing crystalline 3Zn(OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O on a surface of a zinc-based metal plated steel sheet uses a reaction with an aqueous solution.
- a liquid film of a solution containing Zn ions and sulfate ions is formed on a surface of a steel sheet and allowed to stand for a predetermined time, thereby forming the oxide layer containing crystalline 3Zn(OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O on the surface.
- crystalline 3Zn (OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O is not formed.
- the coating weight of a zinc-based metal plated steel sheet including an oxide layer on a surface of the sheet is preferably in the range of 20 to 150 g/m 2 per surface.
- the reason for this is as follows: At an amount of the plating film of less than 20 g/m 2 , the steel sheet has low resistance to corrosion because of a small amount of the plating film An amount of the plating film exceeding 150 g/m 2 results in sufficient resistance to corrosion but may cause peeling of the plating film during processing.
- the Fe concentration in the plating film of the galvannealed steel sheet is preferably in the range of 6% to 14% by mass.
- the reason for this is as follows: At an Fe concentration of less than 6% by mass, a pure Zn phase ( ⁇ phase) remains on the surface, so that the weldability, the paintability, and the like cannot be satisfied. On the other hand, an Fe concentration exceeding 14% by mass results in the formation of a thick ⁇ phase at the interface between the plating film and the steel sheet, thereby reducing adhesion of the plating film.
- the Al concentration needs to be in the range of 0.05% to 0.40% by mass.
- a plating bath For a hot-dip galvanized steel sheet, it is important that a plating bath contain Al in an appropriate amount in order that a thick alloy layer is not formed at the interface between the plating film and the steel sheet.
- the Al concentration needs to be in the range of 0.15% to 0.40% by mass.
- the proportion of the area of a flat portion with respect to a plated surface is desirably in the range of 20% to 80%. At less than 20%, the contact area between a die and a portion (recessed portion) except for the flat portion is increased. With respect to the area of a portion in actual contact with the die, the proportion of the area of the flat portion where an oxide thickness can be assuredly controlled is reduced, thus reducing the effect of improving press formability.
- the portion except for the flat portion serves to hold press oil during press forming. Thus, when the proportion of the area of the portion except for the flat portion is less than 20% (when the proportion of the area of the flat portion exceeds 80%), the lack of oil can easily occur during press forming, so that the effect of improving press formability is reduced.
- a plating bath needs to contain Al.
- additive element components other than Al are not particularly limited. That is, even if Pb, Sb, Si, Sn, Mg, Mn, Ni, Ti, Li, Cu, and other elements are contained or added in addition to Al, the effect is not impaired.
- a plating bath may mainly contain zinc.
- the plating bath may contain other metals and oxides as long as the effect is not impaired.
- a high-tensile steel sheet as an underlying steel sheet provides an effect such as a reduction in weight and is thus preferred.
- a concept regarding a reduction in the weight of an automobile body is that the use of the high-tensile steel sheet can reduce the weight of components (reduction in thickness of the sheet) while the crash performance of the body is maintained.
- press formability tends to decrease as increasing tensile strength.
- the high-tensile steel sheet apparently has inferior press formability.
- the type of steel sheet is not particularly limited. To sufficiently provide the effect of the reduction in weight, application to a high-tensile steel sheet having a tensile strength of 340 MPa or more is preferred.
- a plating film having a coating weight of 60 g/m 2 , an Fe concentration of 10% by mass, and an Al concentration of 0.20% by mass was formed by a common galvannealing process on a cold-rolled steel sheet having a thickness of 0.8 mm. Then the steel sheet was subjected to skin pass rolling. In this case, the proportion of the area of a flat portion varied slightly with sampling positions but was in the range of 40% to 60%.
- Oxidation treatment was performed as follows: The galvannealed steel sheet was immersed in an aqueous solution containing zinc sulfate heptahydrate. The amount of a liquid film attached on a surface was controlled with a rubber roll so as to be 10 g/m 2 . The resulting steel sheet was allowed to stand in air for 10 to 60 seconds, washed with water, and dried. For comparison purposes, an aqueous solution containing zinc nitrate hexahydrate and an acidic solution containing sodium acetate and ferrous sulfate were used. The temperature of all solutions used for the treatment was set to 35° C.
- a hot-dip galvanized steel sheet and an electrogalvanized steel sheet that have a thickness of 0.8 mm were prepared.
- a plating film having a coating weight of 70 g/m 2 was formed by a common hot-dip galvanizing process on the hot-dip galvanized steel sheet.
- the resulting steel sheet was subjected to skin pass rolling.
- a plating film having a coating weight of 50 g/m 2 was formed by a common electrogalvanizing process on the electrogalvanized steel sheet.
- Oxidation treatment was performed as follows: Each of the hot-dip galvanized steel sheet and the electrogalvanized steel sheet was immersed in an aqueous solution containing zinc sulfate heptahydrate. The amount of a liquid film attached on a surface was controlled with a rubber roll so as to be 10 g/m 2 . The resulting steel sheet was allowed to stand in air for 10 to 60 seconds, washed with water, and dried. The temperature of all solutions used for the treatment was set to 35° C.
- FIG. 1 is a schematic front view of an apparatus for measuring a coefficient of friction.
- a sample 1 taken from the steel sheet, used for measuring a coefficient of friction was fixed to a sample stage 2 .
- the sample stage 2 was fixed to an upper surface of a slide table 3 that was movable horizontally.
- a slide-table support 5 that was movable vertically was provided and had rollers 4 in contact with a lower surface of the slide table 3 .
- a bead 6 imposed a pressing load N on the sample 1 for measuring a coefficient of friction.
- a first load cell 7 for measuring the pressing load N was attached to the slide-table support 5 .
- a second load cell 8 for measuring a friction resistance F that allowed the slide table 3 to move horizontally while the pressing load was being imposed on the sample was attached to an end of the slide table 3 .
- lubricant oil wash oil for press, Preton (registered trademark) R352L manufactured by Sugimura Chemical Industrial Co., Ltd. was applied to surfaces of the sample 1 , and then the test was performed.
- FIG. 2 is a schematic perspective view of the shape and dimensions of the bead used. Sliding was performed while the undersurface of the bead 6 is pressed against a surface of the sample 1 .
- the width was 10 mm
- the length in the sliding direction of the sample was 12 mm.
- Lower ends in the sliding direction were in the form of curved surfaces each having a curvature of 4.5 mmR.
- the undersurface of the bead against which the sample was pressed was in the form of a plane with a width of 10 mm and a length in the sliding direction of 3 mm.
- the bead shown in FIG. 2 was used.
- the pressing load N was set to 400 kgf.
- the speed of movement of each sample was set to 100 cm/min.
- the bead shown in FIG. 2 was used.
- the pressing load N was set to 400 kgf.
- the speed of movement of the sample was set to 20 cm/min.
- Measurement of the thickness of each oxide layer was performed with an X-ray fluorescence analyzer. A voltage and a current applied to a tube during measurement were 30 kV and 100 mA, respectively. An analyzing crystal was set to TAP to detect the O-K ⁇ ray. In the case of the measurement of the O-K ⁇ ray, intensities at the background in addition to the peak position were measured to calculate the net intensity of the O-K ⁇ ray. An integral time at each of the peak position and the background was set to 20 seconds.
- Silicon wafer pieces formed by cleavage and including silicon oxide films having a thickness of 96 nm, 54 nm, and 24 nm were placed on the sample stage together with the samples to calculate the intensity of the O-K ⁇ ray on the basis of the silicon oxide films.
- a calibration curve showing the relationship between the thickness of the oxide film and the intensity of the O-K ⁇ ray was formed on the basis of the data. The thickness of the oxide layer of each sample was calculated in terms of the thickness of the silicon oxide film
- the presence of crystalline 3Zn(OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O was determined by an X-ray diffractometry for a thin film.
- An X-ray diffraction pattern was measured by a thin-film method using the Cu-K ⁇ ray at an incident angle of 0.5° .
- a diffraction peak corresponding to a crystal structure of 3Zn(OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O was observed at a diffraction angle (2 ⁇ ) of about 8° to about 12°.
- the presence of crystalline 3Zn(OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O was determined on the basis of the intensity ratio of the diffraction peak to a diffraction peak that was observed at about 42° and that originated from an alloy layer of iron and zinc. It was determined that a film containing crystalline 3Zn(OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O was formed when a peak intensity ratio, i.e., (peak intensity of 3Zn(OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O)/(peak intensity of the alloy of iron and zinc), of 0.020 or more was obtained, wherein the peak intensities calculated by subtracting their respective backgrounds were used.
- a peak intensity ratio i.e., (peak intensity of 3Zn(OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O)/(peak intensity of the alloy of iron and zinc
- the presence of crystalline 3Zn (OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O was determined on the basis of the intensity ratio of a diffraction peak that corresponded to a crystal structure of 3Zn(OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O and that was observed at a diffraction angle (2 ⁇ ) of about 8° to about 12° to a diffraction peak that was observed at about 36° and that originated from a zinc ⁇ layer.
- Table 1 shows conditions of the oxidation treatment for the galvannealed steel sheet and the results.
- Table 2 shows conditions of the oxidation treatment for the hot-dip galvanized steel sheet and the electrogalvanized steel sheet and the results.
- the oxide layer had a thickness of less than 10 nm. An oxide film adequate to improve tribological properties was not formed on a flat portion, thus leading to a high coefficient of friction.
- the peak intensity ratio was 0.020 or more.
- the oxide layer containing crystalline 3Zn(OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O was formed and had a thickness of 10 nm or more, so that the coefficient of friction was stabilized at a low level, thus sufficiently improving tribological properties.
- Galvannealed steel sheets having different strength levels and each having a thickness of 1.2 mm were used. Oxidation treatment was performed as follows: Each of the galvannealed steel sheets was immersed in an aqueous solution (pH: 5.5, temperature: 35° C.) containing zinc sulfate heptahydrate (concentration: 20 g/L). The amount of a liquid film attached on a surface was controlled with a rubber roll so as to be 10 g/m 2 . The resulting steel sheet was allowed to stand in air for 10 to 60 seconds, washed with water, and dried.
- Galvannealing was performed by a common alloying treatment to form a plating film having a coating weight of 45 to 50 g/m 2 and an Fe concentration of 10% to 11% by mass. Then skin pass rolling was performed in such a manner that the proportion of the area of a flat portion was in the range of 40% to 60%.
- a tensile test was performed in compliance with JIS Z2241 using No. 5 test pieces according to JIS Z2201, a longitudinal direction (tensile direction) of each of the test pieces being defined as a direction perpendicular to the rolling direction.
- the bead shown in FIG. 3 was used.
- the pressing load N was set to 400 kgf.
- the speed of movement of each sample was set to 120 cm/min.
- a spherical stretch forming test of each sample having a size of 200 mm ⁇ 200 mm was performed with a punch having a diameter of 150 mm (diameter of a die: 153 mm) to measure the maximum height of a formed portion when the rupture of the sample occurred.
- a fold pressure of 100 ton was applied.
- lubricant oil wash oil for press, Preton (registered trademark) R352L manufactured by Sugimura Chemical Industrial Co., Ltd. was applied to the sample.
- Table 3 shows conditions of the oxidation treatment and the results.
- the oxide layer had a thickness of less than 10 nm.
- An oxide film adequate to improve tribological properties was not formed on a flat portion, thus leading to a high coefficient of friction.
- the peak intensity ratio was 0.020 or more.
- the oxide layer containing crystalline 3Zn(OH) 2 ⁇ ZnSO 4 ⁇ 3-5H 2 O was formed and had a thickness of 10 nm or more, so that the coefficient of friction was stabilized at a low level, thus sufficiently improving tribological properties.
- the zinc-based metal plated steel sheet is excellent in tribological properties and press formability and can thus be applied in many fields, in particular, for automobile bodies.
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Abstract
A zinc-based metal plated steel sheet is excellent in tribological properties during press forming. An oxide layer containing crystalline 3Zn(OH)2·ZnSO4·xH2O is formed on a plated surface. The oxide layer has a thickness of 10 nm or more. The crystalline oxide layer is composed of 3Zn(OH)2·ZnSO4·3-5H2O.
Description
This is a §371 of International Application No. PCT/JP2008/066276, with an international filing date of Sep. 3, 2008 (WO 2009/031699 A1, published Mar. 12, 2009), which is based on Japanese Patent Application Nos. 2007-228517, filed Sep. 4, 2007, and 2008-181082, filed Jul. 11, 2008, the subject matter of which is incorporated by reference.
This disclosure relates to a zinc-based metal plated steel sheet excellent in tribological property during press forming.
Zinc-based metal plated steel sheets are widely used in many fields, in particular, for automobile bodies. When used for automobile bodies, they are subjected to press forming before use. Zinc-based metal plated steel sheets, however, have the disadvantage that their press formability is inferior to that of cold-rolled steel sheets. This is because in a press die, the friction resistance of a surface-treated steel sheet is larger than that of a cold-rolled steel sheet. That is, the surface-treated steel sheet does not smoothly flow into the die at a portion of the surface-treated steel sheet having a large friction resistance to the die and a bead. This is liable to cause rupture of the steel sheet.
In recent years, the demand for high-tensile steel sheets has increased to reduce the weight of automobile bodies. High-tensile steel sheets have press formability inferior to that of mild steel sheets. Thus, high-tensile steel sheets are easily ruptured at portions of high-tensile steel sheets having a large friction resistance to dies and beads.
Galvannealed steel sheets are excellent in weldability and paintability compared with galvanized steel sheets and, thus, more preferably used for automobile bodies.
A galvannealed steel sheet is produced as follows: a steel sheet is subjected to galvanizing and then heat treatment. As a result, an alloying reaction in which Fe in the steel sheet and Zn in a plating layer are diffused occurs, thereby forming a Fe—Zn alloy phase. The Fe—Zn alloy phase is in the form of a layer usually including a Γ phase, δ1 phase, and a ξ phase. Hardness and a melting point tend to decrease as the Fe concentration decreases, i.e., in a sequence of the Γ phase→the δ1 phase→the ξ phase. Thus, a high-hardness, high-melting point film with high Fe concentration is effective from the viewpoint of achieving good tribological properties because adhesion does not easily occur. Galvannealed steel sheets with the emphasis on press formability are produced in such a manner that average Fe concentrations in films are relatively high.
In a film with high Fe concentration, however, hard and brittle Γ phase is readily formed at the interface between the plating film and the steel sheet. Peeling from a surface boundary, i.e., powdering, is disadvantageously liable to occur during processing. Thus, as shown in Japanese Unexamined Patent Application Publication No. 1-319661, for the purpose of striking a balance between tribological properties and anti-powdering properties, a method for forming a hard Fe-based alloy layer as a second layer serving as an upper layer is employed. Disadvantageously, production by the method is costly.
As another method for improving press formability of a zinc-based metal plated steel sheet, a method for applying high-viscosity lubricant oil is widely used. In this method, however, a defect of coating due to a defect of degreasing occurs in an application step because of high viscosity of the lubricant oil. Furthermore, the lack of oil during press forming disadvantageously causes unstable press performance and other problems. Thus, improvement in the press formability of galvannealed steel sheets is strongly required.
As a method to overcome the foregoing problems, Japanese Unexamined Patent Application Publication Nos. 53-60332 and 2-190483 each disclose a technique for improving weldability or processability by subjecting surfaces of a zinc-based metal plated steel sheet to electrolytic treatment, immersion treatment, coating and oxidation treatment, or heat treatment to form an oxide film mainly composed of ZnO.
Japanese Unexamined Patent 4-88196 discloses a technique for improving press formability and chemical conversion treatability by immersing surfaces of a zinc-based metal plated steel sheet in an aqueous solution containing 5 to 60 g/L sodium phosphate and having a pH of 2 to 6, electrolytic treatment, or applying the solution described above to form an oxide film mainly composed of a P oxide.
Japanese Unexamined Patent Application Publication No. 3-191093 discloses a technique for improving press formability and chemical conversion treatability by subjecting surfaces of a zinc-based metal plated steel sheet to electrolytic treatment, immersion treatment, coating, coating and oxidation treatment, or heat treatment to form a Ni oxide.
Japanese Unexamined Patent Application Publication No. 2003-306781 discloses a technique for improving tribological properties by bringing a galvannealed steel sheet into contact with an acidic solution to form an oxide mainly composed of Zn on surfaces of the steel sheet and suppress adhesion between a plating layer and a press die.
The technique for improving press formability by forming an oxide mainly composed of Zn on surfaces of steel sheet disclosed in Japanese Unexamined Patent Application Publication No. 2003-306781 and the like has the advantage over the technique using Ni and the like disclosed in Japanese Unexamined Patent Application Publication No. 3-191093 in production cost and environmental loading because Zn contained in the plated steel sheet is mainly used. In the case where the steel sheet is used for a difficult-to-form component, however, a high degree of press formability is required, so that further improvement in tribological property may be required.
It could therefore be helpful to provide a zinc-based metal plated steel sheet excellent in tribological properties during press forming compared with the technique for improving press formability by forming an oxide mainly composed of Zn on surfaces of a steel sheet.
We conducted studies on tribological properties of a galvannealed steel sheet and found the following:
-
- A flat portion on a surface of the galvannealed steel sheet is present as a projection compared with a surrounding portion. The flat portion mainly comes into actual contact with a press die during press forming. Thus, the presence of an oxide layer containing crystalline 3Zn (OH)2·ZnSO4·3-5H2O in the flat portion prevents adhesion between a plating layer and the die. In addition to the galvannealed steel sheet, also for a hot-dip galvanized steel sheet and an electrogalvanized steel sheet that are not subjected to allying treatment, the presence of an oxide layer containing crystalline 3Zn(OH)2·ZnSO4·3-5H2O on a plated surface prevents adhesion between a plating layer and the die.
We thus provide:
-
- (1) A zinc-based metal plated steel sheet includes an oxide layer containing crystalline 3Zn(OH)2·ZnSO4·xH2O, in which the oxide layer is formed on a plated surface, and the oxide layer has a thickness of 10 nm or more.
- (2) In the zinc-based metal plated steel sheet described in item (1), the crystalline oxide layer is composed of 3Zn (OH)2·ZnSO4·3-5H2O.
- The zinc-based metal plated steel sheet has a low friction resistance and stably provides excellent press formability.
Reference numerals in the drawings represent the following:
1 | sample used for measuring coefficient of |
2 | |
3 | slide table |
4 | roller |
5 | slide-table support |
6 | bead |
7 | first load cell |
8 | second load cell |
9 | rail |
N | pressing load |
F | friction resistance |
P | tensile load |
Our galvannealed steel sheets have an uneven surface due to the difference in reactivity at the interface between the steel sheet and a plating film. However, the planarization of a surface layer by a method such as skin pass rolling reduces irregularities of a plated surface. Thus, a force required to press projections on the plated surface with a die during press forming can be reduced to improve tribological properties.
A flat portion on a surface of a galvannealed steel sheet is a portion with which a die comes into direct contact during press forming. Thus, the presence of a hard and high-melting-point material that prevents adhesion to the die is important in improving tribological properties. Also in a hot-dip galvanized steel sheet and an electrogalvanized steel sheet which have surface irregularities smaller than those of the galvannealed steel sheet, each of their surfaces is naturally a portion with which a die comes into direct contact during press forming. Thus, the presence of a hard and high-melting-point material in their surface layers is important for improving tribological properties.
Also from this point of view, the formation of an oxide layer on a surface layer is effective in improving tribological properties. An oxide layer containing crystalline 3Zn(OH)2·ZnSO4·xH2O is very effective. In particular, an oxide layer containing crystalline 3Zn(OH)2·ZnSO4·3-5H2O is significantly effective.
Whether crystalline 3Zn(OH)2·ZnSO4·3-5H2O is present in the oxide layer or not was determined by measuring an X-ray diffraction pattern of the oxide layer using X-ray diffractometry for a thin film and checking the resulting pattern against a standard pattern described in an ICDD card. The results demonstrated that peaks originating from oxides were observed at a diffraction angle (2θ) of about 8° to about 12° and that these peaks were assigned to 3Zn(OH)2·ZnSO4·3H2O (ICDD card: 39-689), 3Zn(OH)2·ZnSO4·4H2O (ICDD card: 44-673), and 3Zn(OH)2·ZnSO4·5H2O (ICDD card: 39-688), which are trihydrate, tetrahydrate, and pentahydrate, respectively.
A thickness of the oxide layer on the surface plating layer of 10 nm or more results in a zinc-based metal plated steel sheet having good tribological properties. A thickness of 20 nm or more is more effective. This is because the oxide layer remains even if the oxide layer on the surface layer is worn in press forming in which the contact area between a die and a workpiece is large, thus not leading to a reduction in tribological properties. On the other hand, the upper limit of the thickness is not set. A thickness exceeding 200 nm results in a reduction in etch rate with a chemical conversion treatment liquid even when the oxide layer has Zn—OH bonds, thus leading to difficulty in the formation of a dense, uniform chemical conversion film. The thickness is therefore desirably 200 nm or less.
The most effective method for forming an oxide layer containing crystalline 3Zn(OH)2·ZnSO4·3-5H2O on a surface of a zinc-based metal plated steel sheet uses a reaction with an aqueous solution. In particular, a liquid film of a solution containing Zn ions and sulfate ions is formed on a surface of a steel sheet and allowed to stand for a predetermined time, thereby forming the oxide layer containing crystalline 3Zn(OH)2·ZnSO4·3-5H2O on the surface. In the case of using a solution containing only Zn ions, crystalline 3Zn (OH)2·ZnSO4·3-5H2O is not formed. In the case of using the solution containing Zn ions and sulfate ions, a higher sulfate ion concentration results in a tendency to promote the formation of crystalline 3Zn(OH)2·ZnSO4·3-5H2O. Furthermore, higher concentrations of Zn ions and sulfate ions results in a tendency to form an oxide film having a larger thickness.
The coating weight of a zinc-based metal plated steel sheet including an oxide layer on a surface of the sheet is preferably in the range of 20 to 150 g/m2 per surface. The reason for this is as follows: At an amount of the plating film of less than 20 g/m2, the steel sheet has low resistance to corrosion because of a small amount of the plating film An amount of the plating film exceeding 150 g/m2 results in sufficient resistance to corrosion but may cause peeling of the plating film during processing. In particular, with respect to a galvannealed steel sheet, when galvannealing is performed in such a manner that good weldability and paintability, which are features of the galvannealed steel sheet, are satisfied, the formation of a Γ phase cannot be avoided at the interface between the plating film and the steel sheet, causing peeling of the plating film, e.g., powdering.
The Fe concentration in the plating film of the galvannealed steel sheet is preferably in the range of 6% to 14% by mass. The reason for this is as follows: At an Fe concentration of less than 6% by mass, a pure Zn phase (η phase) remains on the surface, so that the weldability, the paintability, and the like cannot be satisfied. On the other hand, an Fe concentration exceeding 14% by mass results in the formation of a thick Γ phase at the interface between the plating film and the steel sheet, thereby reducing adhesion of the plating film. To control the Fe concentration within the range, it is important to allow a plating bath to contain an appropriate amount of Al. The Al concentration needs to be in the range of 0.05% to 0.40% by mass.
For a hot-dip galvanized steel sheet, it is important that a plating bath contain Al in an appropriate amount in order that a thick alloy layer is not formed at the interface between the plating film and the steel sheet. The Al concentration needs to be in the range of 0.15% to 0.40% by mass.
The proportion of the area of a flat portion with respect to a plated surface is desirably in the range of 20% to 80%. At less than 20%, the contact area between a die and a portion (recessed portion) except for the flat portion is increased. With respect to the area of a portion in actual contact with the die, the proportion of the area of the flat portion where an oxide thickness can be assuredly controlled is reduced, thus reducing the effect of improving press formability. The portion except for the flat portion serves to hold press oil during press forming. Thus, when the proportion of the area of the portion except for the flat portion is less than 20% (when the proportion of the area of the flat portion exceeds 80%), the lack of oil can easily occur during press forming, so that the effect of improving press formability is reduced.
In the case of producing a galvannealed steel sheet or hot-dip galvanized steel sheet, a plating bath needs to contain Al. However, additive element components other than Al are not particularly limited. That is, even if Pb, Sb, Si, Sn, Mg, Mn, Ni, Ti, Li, Cu, and other elements are contained or added in addition to Al, the effect is not impaired.
In the case of producing an electrogalvanized steel sheet, a plating bath may mainly contain zinc. The plating bath may contain other metals and oxides as long as the effect is not impaired.
In a zinc-based metal plated steel sheet, the use of a high-tensile steel sheet as an underlying steel sheet provides an effect such as a reduction in weight and is thus preferred. For example, a concept regarding a reduction in the weight of an automobile body is that the use of the high-tensile steel sheet can reduce the weight of components (reduction in thickness of the sheet) while the crash performance of the body is maintained. In general, however, press formability tends to decrease as increasing tensile strength. The high-tensile steel sheet apparently has inferior press formability. We conducted intensive studies to improve the press formability of a high-tensile steel sheet and have found that the formation of an oxide layer containing crystalline 3Zn(OH)2·ZnSO4·3-5H2O on a surface layer extremely improves the press formability of the high-tensile steel sheet. This enables the high-tensile steel sheet to be applied to applications in which the use of the high-tensile steel sheet is difficult from the viewpoint of formability, thus achieving the effect of the reduction in weight described above. The type of steel sheet is not particularly limited. To sufficiently provide the effect of the reduction in weight, application to a high-tensile steel sheet having a tensile strength of 340 MPa or more is preferred.
Our steel sheets and methods will be described in further detail by examples.
A plating film having a coating weight of 60 g/m2, an Fe concentration of 10% by mass, and an Al concentration of 0.20% by mass was formed by a common galvannealing process on a cold-rolled steel sheet having a thickness of 0.8 mm. Then the steel sheet was subjected to skin pass rolling. In this case, the proportion of the area of a flat portion varied slightly with sampling positions but was in the range of 40% to 60%.
Oxidation treatment was performed as follows: The galvannealed steel sheet was immersed in an aqueous solution containing zinc sulfate heptahydrate. The amount of a liquid film attached on a surface was controlled with a rubber roll so as to be 10 g/m2. The resulting steel sheet was allowed to stand in air for 10 to 60 seconds, washed with water, and dried. For comparison purposes, an aqueous solution containing zinc nitrate hexahydrate and an acidic solution containing sodium acetate and ferrous sulfate were used. The temperature of all solutions used for the treatment was set to 35° C.
Furthermore, a hot-dip galvanized steel sheet and an electrogalvanized steel sheet that have a thickness of 0.8 mm were prepared. A plating film having a coating weight of 70 g/m2 was formed by a common hot-dip galvanizing process on the hot-dip galvanized steel sheet. The resulting steel sheet was subjected to skin pass rolling. A plating film having a coating weight of 50 g/m2 was formed by a common electrogalvanizing process on the electrogalvanized steel sheet.
Oxidation treatment was performed as follows: Each of the hot-dip galvanized steel sheet and the electrogalvanized steel sheet was immersed in an aqueous solution containing zinc sulfate heptahydrate. The amount of a liquid film attached on a surface was controlled with a rubber roll so as to be 10 g/m2. The resulting steel sheet was allowed to stand in air for 10 to 60 seconds, washed with water, and dried. The temperature of all solutions used for the treatment was set to 35° C.
The measurement of coefficients of friction and measurement of thicknesses of oxide layers and analysis of 3Zn(OH)2·ZnSO4·3-5H2O of the oxidation-treated plated steel sheets were performed as follows. For comparison purposes, steel sheets that were not subjected to oxidation treatment were also studied in the same way as above.
(1) Test for Evaluating Press Formability (Test for Measuring Coefficient of Friction)
To evaluate press formability, coefficient of friction of each of the samples was measured. FIG. 1 is a schematic front view of an apparatus for measuring a coefficient of friction. As shown in the figure, a sample 1, taken from the steel sheet, used for measuring a coefficient of friction was fixed to a sample stage 2. The sample stage 2 was fixed to an upper surface of a slide table 3 that was movable horizontally. A slide-table support 5 that was movable vertically was provided and had rollers 4 in contact with a lower surface of the slide table 3. By raising the slide-table support 5, a bead 6 imposed a pressing load N on the sample 1 for measuring a coefficient of friction. A first load cell 7 for measuring the pressing load N was attached to the slide-table support 5. A second load cell 8 for measuring a friction resistance F that allowed the slide table 3 to move horizontally while the pressing load was being imposed on the sample was attached to an end of the slide table 3. As lubricant oil, wash oil for press, Preton (registered trademark) R352L manufactured by Sugimura Chemical Industrial Co., Ltd. was applied to surfaces of the sample 1, and then the test was performed.
The test for measuring a coefficient of friction was performed under two conditions described below.
Condition 1
The bead shown in FIG. 2 was used. The pressing load N was set to 400 kgf. The speed of movement of each sample (the speed of horizontal movement of the slide table 3) was set to 100 cm/min.
The bead shown in FIG. 2 was used. The pressing load N was set to 400 kgf. The speed of movement of the sample (the speed of horizontal movement of the slide table 3) was set to 20 cm/min.
Coefficients μ of friction between the samples and the bead were calculated using the following formula: μ=F/N.
(2) Measurement of Thickness of Oxide Layer
Measurement of the thickness of each oxide layer was performed with an X-ray fluorescence analyzer. A voltage and a current applied to a tube during measurement were 30 kV and 100 mA, respectively. An analyzing crystal was set to TAP to detect the O-Kα ray. In the case of the measurement of the O-Kα ray, intensities at the background in addition to the peak position were measured to calculate the net intensity of the O-Kα ray. An integral time at each of the peak position and the background was set to 20 seconds.
Silicon wafer pieces formed by cleavage and including silicon oxide films having a thickness of 96 nm, 54 nm, and 24 nm were placed on the sample stage together with the samples to calculate the intensity of the O-Kα ray on the basis of the silicon oxide films. A calibration curve showing the relationship between the thickness of the oxide film and the intensity of the O-Kα ray was formed on the basis of the data. The thickness of the oxide layer of each sample was calculated in terms of the thickness of the silicon oxide film
(3) Determination of Presence of Crystalline 3Zn(OH)2·ZnSO4·3-5H2O
The presence of crystalline 3Zn(OH)2·ZnSO4·3-5H2O was determined by an X-ray diffractometry for a thin film. An X-ray diffraction pattern was measured by a thin-film method using the Cu-Kα ray at an incident angle of 0.5° . A diffraction peak corresponding to a crystal structure of 3Zn(OH)2·ZnSO4·3-5H2O was observed at a diffraction angle (2θ) of about 8° to about 12°.
For the galvannealed steel sheet, the presence of crystalline 3Zn(OH)2·ZnSO4·3-5H2O was determined on the basis of the intensity ratio of the diffraction peak to a diffraction peak that was observed at about 42° and that originated from an alloy layer of iron and zinc. It was determined that a film containing crystalline 3Zn(OH)2·ZnSO4·3-5H2O was formed when a peak intensity ratio, i.e., (peak intensity of 3Zn(OH)2·ZnSO4·3-5H2O)/(peak intensity of the alloy of iron and zinc), of 0.020 or more was obtained, wherein the peak intensities calculated by subtracting their respective backgrounds were used.
For each of the hot-dip galvanized steel sheet and the electrogalvanized steel sheet, the presence of crystalline 3Zn (OH)2·ZnSO4·3-5H2O was determined on the basis of the intensity ratio of a diffraction peak that corresponded to a crystal structure of 3Zn(OH)2·ZnSO4·3-5H2O and that was observed at a diffraction angle (2θ) of about 8° to about 12° to a diffraction peak that was observed at about 36° and that originated from a zinc η layer. It was determined that a film containing crystalline 3Zn(OH)2·ZnSO4·3-5H2O was formed when a peak intensity ratio, i.e., (peak intensity of 3Zn(OH)2·ZnSO4·3-5H2O)/(peak intensity of the zinc η layer), of 0.020 or more was obtained, wherein the peak intensities calculated by subtracting their respective backgrounds were used.
The peaks observed at a diffraction angle (2θ) of about 8° to about 12° were assigned to 3Zn(OH)2·ZnSO4·3H2O (ICDD card: 39-689), 3Zn(OH)2·ZnSO4·4H2O (ICDD card: 44-673), and 3Zn(OH)2·ZnSO4·5H2O (ICDD card: 39-688), which are trihydrate, tetrahydrate, and pentahydrate, respectively.
Table 1 shows conditions of the oxidation treatment for the galvannealed steel sheet and the results. Table 2 shows conditions of the oxidation treatment for the hot-dip galvanized steel sheet and the electrogalvanized steel sheet and the results.
TABLE 1 | |||||||
Time until | Thickness | ||||||
washing | of | Coefficient of friction | Peak |
with | oxide film | Condition | Condition | intensity | ||||
No. | Solution used | pH of solution | water (s) | (nm) | 1 | 2 | ratio *) | Remarks |
1 | — | — | — | 9 | 0.175 | 0.256 | — | Comparative Example 1 |
2 | Zinc sulfate heptahydrate | 5.5 | 10 s | 28 | 0.133 | 0.169 | 0.025 | Inventive Example 1 |
3 | 20 g/l | 30 s | 34 | 0.134 | 0.163 | 0.049 | Inventive Example 2 | |
4 | 60 s | 45 | 0.132 | 0.163 | 0.080 | Inventive Example 3 | ||
5 | Zinc sulfate heptahydrate | 5.2 | 10 s | 30 | 0.130 | 0.168 | 0.031 | Inventive Example 4 |
6 | 50 g/l | 30 s | 36 | 0.129 | 0.166 | 0.054 | Inventive Example 5 | |
7 | 60 s | 52 | 0.126 | 0.158 | 0.107 | Inventive Example 6 | ||
8 | Zinc nitrate hexahydrate | 5.6 | 10 s | 22 | 0.160 | 0.228 | — | Comparative Example 2 |
9 | 20 g/L | 30 s | 28 | 0.159 | 0.220 | 0.008 | Comparative Example 3 | |
10 | 60 s | 31 | 0.155 | 0.215 | 0.011 | Comparative Example 4 | ||
11 | Zinc nitrate hexahydrate | 5.2 | 10 s | 24 | 0.158 | 0.225 | 0.012 | Comparative Example 5 |
12 | 50 g/L | 30 s | 32 | 0.159 | 0.218 | 0.010 | Comparative Example 6 | |
13 | 60 s | 40 | 0.155 | 0.220 | 0.013 | Comparative Example 7 | ||
14 | Sodium acetate | 2.0 | 10 s | 18 | 0.153 | 0.181 | — | Comparative Example 8 |
15 | Ferrous sulfate | (pH was adjusted | 30 s | 24 | 0.152 | 0.175 | 0.006 | Comparative Example 8 |
16 | 40 g/L each | to 2.0 with | 60 s | 35 | 0.148 | 0.177 | 0.017 | Comparative Example 9 |
sulfuric acid) | ||||||||
*) No peak was observed at 8° to 12°. |
TABLE 2 | |||||||
Time until | Thickness of | Peak | |||||
pH of | washing with | oxide film | Coefficient of friction | intensity |
No. | Sample *1) | Solution used | solution | water (s) | (nm) | Condition 1 | |
ratio *2) |
17 | GI | — | — | — | 6 | 0.135 | 0.286 | — |
18 | Zinc sulfate | 5.2 | 10 s | 25 | 0.135 | 0.162 | 0.022 | |
19 | heptahydrate | 30 s | 35 | 0.128 | 0.160 | 0.041 | ||
20 | 50 g/l | 60 s | 44 | 0.125 | 0.158 | 0.080 | ||
21 | EG | — | — | — | 9 | 0.146 | 0.286 | — |
22 | Zinc sulfate | 5.2 | 10 s | 27 | 0.135 | 0.169 | 0.024 | |
23 | heptahydrate | 30 s | 34 | 0.131 | 0.168 | 0.043 | ||
24 | 50 g/L | 60 s | 43 | 0.129 | 0.160 | 0.075 | ||
*1) GI: hot-dip galvanized steel sheet, EG: electrogalvanized steel sheet | ||||||||
*2) No peak was observed at 8° to 12°. |
The results from Tables 1 and 2 show the following.
In each of Nos. 1, 17, and 21, which were not subjected to oxidation treatment, the oxide layer had a thickness of less than 10 nm. An oxide film adequate to improve tribological properties was not formed on a flat portion, thus leading to a high coefficient of friction.
In each of Nos. 2 to 7, 18 to 20, and 22 to 24, the peak intensity ratio was 0.020 or more. The oxide layer containing crystalline 3Zn(OH)2·ZnSO4·3-5H2O was formed and had a thickness of 10 nm or more, so that the coefficient of friction was stabilized at a low level, thus sufficiently improving tribological properties.
In each of Nos. 8 to 16, although the oxide layer having a thickness of 10 nm or more was formed on a flat portion, the peak intensity ratio was less than 0.020. Crystalline 3Zn(OH)2·ZnSO4·3-5H2O was not formed. A high coefficient of friction was measured. The effect of sufficiently improving tribological properties was not provided.
Galvannealed steel sheets having different strength levels and each having a thickness of 1.2 mm were used. Oxidation treatment was performed as follows: Each of the galvannealed steel sheets was immersed in an aqueous solution (pH: 5.5, temperature: 35° C.) containing zinc sulfate heptahydrate (concentration: 20 g/L). The amount of a liquid film attached on a surface was controlled with a rubber roll so as to be 10 g/m2. The resulting steel sheet was allowed to stand in air for 10 to 60 seconds, washed with water, and dried. Galvannealing was performed by a common alloying treatment to form a plating film having a coating weight of 45 to 50 g/m2 and an Fe concentration of 10% to 11% by mass. Then skin pass rolling was performed in such a manner that the proportion of the area of a flat portion was in the range of 40% to 60%.
The measurement of thicknesses of oxide layers and analysis of 3Zn(OH)2·ZnSO4·3-5H2O of the oxidation-treated galvannealed steel sheets were performed by the procedure described in Example 1. Furthermore, the measurement of mechanical properties and evaluation of press formability of the steel sheets were performed. Press formability was evaluated by a test for measuring a coefficient of friction and a stretch forming test. For comparison purposes, steel sheets that were not subjected to oxidation treatment were also studied in the same way as above.
(1) Measurement of Mechanical Property
A tensile test was performed in compliance with JIS Z2241 using No. 5 test pieces according to JIS Z2201, a longitudinal direction (tensile direction) of each of the test pieces being defined as a direction perpendicular to the rolling direction.
(2) Test for Evaluating Press Formability (Test for Measuring Coefficient of Friction)
Coefficients of friction of samples were measured by the procedure described in Example 1 under conditions 3.
The bead shown in FIG. 3 was used. The pressing load N was set to 400 kgf. The speed of movement of each sample (the speed of horizontal movement of the slide table 3) was set to 120 cm/min. Coefficients μ of friction between the samples and the bead were calculated using the following formula: μ=F/N.
(3) Test for Evaluating Press Formability (Stretch Forming Test)
A spherical stretch forming test of each sample having a size of 200 mm×200 mm was performed with a punch having a diameter of 150 mm (diameter of a die: 153 mm) to measure the maximum height of a formed portion when the rupture of the sample occurred. In this case, to suppress the feed of the sample, a fold pressure of 100 ton was applied. As lubricant oil, wash oil for press, Preton (registered trademark) R352L manufactured by Sugimura Chemical Industrial Co., Ltd. was applied to the sample.
Table 3 shows conditions of the oxidation treatment and the results.
TABLE 3 | ||||||||
Time until | Coefficient | Stretch forming | ||||||
Sample | washing | Thickness | Peak | of friction | test Height |
TS | YS | El | Oxidation | with | of oxide | intensity | Condition | of formed | ||
No | (MPa) | (MPa) | (%) | treatment | water (s) | film nm | ratio *) | 3 | portion mm | Remarks |
1 | 350 | 240 | 42 | Performed | 10 | 32 | 0.025 | 0.160 | 45.6 | Inventive Example |
2 | 350 | 240 | 42 | Not performed | — | 6 | — | 0.225 | 40.1 | Comparative Example |
3 | 450 | 310 | 38 | Performed | 10 | 31 | 0.025 | 0.157 | 44.0 | Inventive Example |
4 | 450 | 310 | 38 | Not performed | — | 8 | — | 0.219 | 38.5 | Comparative Example |
5 | 620 | 390 | 29 | Performed | 10 | 30 | 0.022 | 0.156 | 41.1 | Inventive Example |
6 | 620 | 390 | 29 | Not performed | — | 6 | — | 0.224 | 35.5 | Comparative Example |
7 | 890 | 590 | 19 | Performed | 10 | 30 | 0.022 | 0.157 | 37.5 | Inventive Example |
8 | 890 | 590 | 19 | Not performed | — | 7 | — | 0.213 | 31.8 | Comparative Example |
9 | 1060 | 660 | 15 | Performed | 10 | 31 | 0.024 | 0.159 | 36.2 | Inventive Example |
10 | 1060 | 660 | 15 | Not performed | — | 7 | — | 0.225 | 30.5 | Comparative Example |
11 | 1500 | 800 | 13 | Performed | 10 | 30 | 0.022 | 0.155 | 35.3 | Inventive Example |
12 | 1500 | 800 | 13 | Not performed | — | 7 | — | 0.215 | 29.5 | Comparative Example |
13 | 2000 | 1100 | 10 | Performed | 10 | 31 | 0.022 | 0.156 | 34.4 | Inventive Example |
14 | 2000 | 1100 | 10 | Not performed | — | 8 | — | 0.210 | 28.6 | Comparative Example |
*) No peak was observed at 8° to 12°. |
The results from Table 3 show the following.
In each of the samples that were not subjected to oxidation treatment (Comparative Examples: Nos. 2, 4, 6, 8, 10, 12, and 14), the oxide layer had a thickness of less than 10 nm. An oxide film adequate to improve tribological properties was not formed on a flat portion, thus leading to a high coefficient of friction.
In each of the samples that were subjected to oxidation treatment (Inventive Examples: Nos. 1, 3, 5, 7, 9, 11, and 13), the peak intensity ratio was 0.020 or more. The oxide layer containing crystalline 3Zn(OH)2·ZnSO4·3-5H2O was formed and had a thickness of 10 nm or more, so that the coefficient of friction was stabilized at a low level, thus sufficiently improving tribological properties.
Comparisons between the steel sheets having the same strength level (Nos. 1 and 2, Nos. 3 and 4, Nos. 5 and 6, Nos. 7 and 8, Nos. 9 and 10, Nos. 11 and 12, and Nos. 13 and 14) showed that heights of formed portions of samples that were subjected to oxidation treatment (Inventive Example) was higher than those of samples that were not subjected to oxidation treatment (Comparative Example) and that the samples that were subjected to oxidation treatment had sufficiently improved press formability.
The zinc-based metal plated steel sheet is excellent in tribological properties and press formability and can thus be applied in many fields, in particular, for automobile bodies.
Claims (4)
1. A galvannealed steel sheet comprising an oxide layer containing crystalline 3Zn(OH)2·ZnSO4·xH2O, wherein the oxide layer is located on a plated surface, the oxide layer has a thickness of 10 nm to 200 nm, the plating film of the galvannealed steel sheet contains 6-14% by mass Fe and a proportion of an area of a flat portion with respect to the plated surface is 20% to 80%.
2. The galvannealed steel sheet according to claim 1 , wherein the crystalline oxide layer is composed of 3Zn(OH)2·ZnSO4·3-5H2O.
3. The galvannealed steel sheet according to claim 1 , having a tensile strength of 340 MPa or more.
4. The galvannealed steel sheet according to claim 1 , wherein the oxide layer consists essentially of crystalline 3Zn(OH)2·ZnSO4·xH2O.
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Publication number | Priority date | Publication date | Assignee | Title |
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US11319631B2 (en) * | 2017-10-12 | 2022-05-03 | Arcelormittal | Metal sheet treatment method and metal sheet treated with this method |
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Citations (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5360332A (en) | 1976-11-10 | 1978-05-30 | Nippon Steel Corp | Alloyed zincciron plate having excellent weldability |
US4226645A (en) * | 1979-01-08 | 1980-10-07 | Republic Steel Corp. | Steel well casing and method of production |
US4242400A (en) * | 1977-10-15 | 1980-12-30 | E M I Limited | Magnetically structured materials |
US4244998A (en) * | 1976-12-06 | 1981-01-13 | E M I Limited | Patterned layers including magnetizable material |
US4261965A (en) * | 1979-06-14 | 1981-04-14 | Matsushita Electric Industrial Co., Ltd. | Basic zinc compound flake-like crystalline particle and method for preparation thereof |
US4734536A (en) * | 1985-10-03 | 1988-03-29 | Asahi Kasei Kogyo Kabushiki Kaisha | Process for producing cycloolefins |
JPH01319661A (en) | 1988-06-21 | 1989-12-25 | Kawasaki Steel Corp | Alloying hot dip galvanized steel sheet excellent in press formability |
JPH02190483A (en) | 1989-01-19 | 1990-07-26 | Nippon Steel Corp | Galvanized steel sheet having superior press formability |
JPH03191093A (en) | 1989-12-19 | 1991-08-21 | Nippon Steel Corp | Galvanized steel sheet excellent in press formability and chemical conversion treating property |
JPH0488196A (en) | 1990-08-01 | 1992-03-23 | Nippon Steel Corp | Galvanized steel sheet excellent in press workability and chemical conversion treating property |
JPH088196A (en) | 1994-06-22 | 1996-01-12 | Nec Corp | Formation of tungsten pattern |
US5641578A (en) * | 1990-05-18 | 1997-06-24 | Nkk Corporation | Weldable black steel sheet |
US6495788B1 (en) * | 1999-12-09 | 2002-12-17 | Charmilles Technologies Sa | Electrode for machining a piece by electro-erosion and its process for production |
US20030003322A1 (en) * | 2001-04-16 | 2003-01-02 | Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd) | Galvannealed steel sheet superior in workability |
US6528182B1 (en) * | 1998-09-15 | 2003-03-04 | Sollac | Zinc coated steel plates coated with a pre-lubricating hydroxysulphate layer and methods for obtaining same |
US20030089201A1 (en) * | 2001-07-13 | 2003-05-15 | Teck Cominco Metals Ltd. | Heap bioleaching process for the extraction of zinc |
JP2003306781A (en) | 2002-04-18 | 2003-10-31 | Jfe Steel Kk | Method of producing hot dip galvannealed steel sheet |
US20040258849A1 (en) * | 2003-06-23 | 2004-12-23 | Rodney Boyd | System for hot-dip galvanizing metal components |
US20050066773A1 (en) * | 2001-07-13 | 2005-03-31 | Harlamovs Juris R | Heap bioleaching process for the extraction of zinc |
US20050126338A1 (en) * | 2003-02-24 | 2005-06-16 | Nanoproducts Corporation | Zinc comprising nanoparticles and related nanotechnology |
JP2007517135A (en) | 2003-12-24 | 2007-06-28 | アルセロール・フランス | Surface treatment with hydroxysulfate |
US7291402B2 (en) * | 2002-07-23 | 2007-11-06 | Jfe Steel Corporation | Surface-treated steel sheets of good white rust resistance, and method for producing them |
JP2010202960A (en) * | 2009-03-06 | 2010-09-16 | Jfe Steel Corp | Zinc-base-plated steel sheet onto the surface of which molten metal hardly deposits |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07331403A (en) * | 1994-06-07 | 1995-12-19 | Nippon Steel Corp | Production of high strength galvannealed steel sheet |
JP3908845B2 (en) * | 1998-01-07 | 2007-04-25 | 日本パーカライジング株式会社 | Surface treatment method for hot dip galvanized steel sheet |
JP3879266B2 (en) * | 1998-08-04 | 2007-02-07 | 住友金属工業株式会社 | Alloyed hot-dip galvanized steel sheet excellent in formability and manufacturing method thereof |
JP3346338B2 (en) * | 1999-05-18 | 2002-11-18 | 住友金属工業株式会社 | Galvanized steel sheet and method for producing the same |
JP3613195B2 (en) * | 2000-03-07 | 2005-01-26 | Jfeスチール株式会社 | Alloy hot-dip galvanized steel sheet |
WO2001081646A1 (en) * | 2000-04-24 | 2001-11-01 | Nkk Corporation | Galvannealed sheet steel and method for production thereof |
JP2001329352A (en) * | 2000-05-19 | 2001-11-27 | Sumitomo Metal Ind Ltd | Galvannealed steel sheet excellent in slidability |
BR0211639A (en) * | 2001-08-03 | 2005-06-28 | Elisha Holding Llc | Non-electric method for treating a substrate, aqueous medium for use in a non-electric process for treating a conductive surface and article comprising an electrically conductive substrate |
JP3582511B2 (en) * | 2001-10-23 | 2004-10-27 | 住友金属工業株式会社 | Surface-treated steel for hot press forming and its manufacturing method |
JP3570409B2 (en) * | 2001-11-01 | 2004-09-29 | Jfeスチール株式会社 | Galvannealed steel sheet |
JP2003138361A (en) * | 2001-11-01 | 2003-05-14 | Nkk Corp | Galvannealed steel sheet |
KR20050022264A (en) * | 2003-08-29 | 2005-03-07 | 제이에프이 스틸 가부시키가이샤 | Method for manufacturing galvannealed steel sheet and galvannealed steel sheet |
JP4539256B2 (en) * | 2003-09-17 | 2010-09-08 | Jfeスチール株式会社 | Alloy hot-dip galvanized steel sheet |
JP2005120445A (en) * | 2003-10-17 | 2005-05-12 | Jfe Steel Kk | Galvanized steel sheet excellent in press formability |
ITTO20060139A1 (en) * | 2006-02-27 | 2007-08-28 | Bridgestone Corp | VULCANIZABLE RUBBER COMPOUND CONTAINING SILICE |
JP2007231375A (en) * | 2006-03-01 | 2007-09-13 | Jfe Steel Kk | Galvannealed steel sheet |
-
2008
- 2008-07-11 JP JP2008181082A patent/JP5239570B2/en active Active
- 2008-09-03 CA CA2784174A patent/CA2784174C/en not_active Expired - Fee Related
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-
2011
- 2011-12-08 US US13/314,547 patent/US8623514B2/en active Active
-
2012
- 2012-02-06 JP JP2012022614A patent/JP5522185B2/en active Active
Patent Citations (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5360332A (en) | 1976-11-10 | 1978-05-30 | Nippon Steel Corp | Alloyed zincciron plate having excellent weldability |
US4244998A (en) * | 1976-12-06 | 1981-01-13 | E M I Limited | Patterned layers including magnetizable material |
US4242400A (en) * | 1977-10-15 | 1980-12-30 | E M I Limited | Magnetically structured materials |
US4226645A (en) * | 1979-01-08 | 1980-10-07 | Republic Steel Corp. | Steel well casing and method of production |
US4261965A (en) * | 1979-06-14 | 1981-04-14 | Matsushita Electric Industrial Co., Ltd. | Basic zinc compound flake-like crystalline particle and method for preparation thereof |
US4734536A (en) * | 1985-10-03 | 1988-03-29 | Asahi Kasei Kogyo Kabushiki Kaisha | Process for producing cycloolefins |
JPH01319661A (en) | 1988-06-21 | 1989-12-25 | Kawasaki Steel Corp | Alloying hot dip galvanized steel sheet excellent in press formability |
JPH02190483A (en) | 1989-01-19 | 1990-07-26 | Nippon Steel Corp | Galvanized steel sheet having superior press formability |
JPH03191093A (en) | 1989-12-19 | 1991-08-21 | Nippon Steel Corp | Galvanized steel sheet excellent in press formability and chemical conversion treating property |
US5641578A (en) * | 1990-05-18 | 1997-06-24 | Nkk Corporation | Weldable black steel sheet |
JPH0488196A (en) | 1990-08-01 | 1992-03-23 | Nippon Steel Corp | Galvanized steel sheet excellent in press workability and chemical conversion treating property |
JPH088196A (en) | 1994-06-22 | 1996-01-12 | Nec Corp | Formation of tungsten pattern |
US6528182B1 (en) * | 1998-09-15 | 2003-03-04 | Sollac | Zinc coated steel plates coated with a pre-lubricating hydroxysulphate layer and methods for obtaining same |
US6495788B1 (en) * | 1999-12-09 | 2002-12-17 | Charmilles Technologies Sa | Electrode for machining a piece by electro-erosion and its process for production |
US20030003322A1 (en) * | 2001-04-16 | 2003-01-02 | Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd) | Galvannealed steel sheet superior in workability |
US20030089201A1 (en) * | 2001-07-13 | 2003-05-15 | Teck Cominco Metals Ltd. | Heap bioleaching process for the extraction of zinc |
US20050066773A1 (en) * | 2001-07-13 | 2005-03-31 | Harlamovs Juris R | Heap bioleaching process for the extraction of zinc |
US20070193413A9 (en) * | 2001-07-13 | 2007-08-23 | Harlamovs Juris R | Heap bioleaching process for the extraction of zinc |
JP2003306781A (en) | 2002-04-18 | 2003-10-31 | Jfe Steel Kk | Method of producing hot dip galvannealed steel sheet |
US7291402B2 (en) * | 2002-07-23 | 2007-11-06 | Jfe Steel Corporation | Surface-treated steel sheets of good white rust resistance, and method for producing them |
US20050126338A1 (en) * | 2003-02-24 | 2005-06-16 | Nanoproducts Corporation | Zinc comprising nanoparticles and related nanotechnology |
US20040258849A1 (en) * | 2003-06-23 | 2004-12-23 | Rodney Boyd | System for hot-dip galvanizing metal components |
JP2007517135A (en) | 2003-12-24 | 2007-06-28 | アルセロール・フランス | Surface treatment with hydroxysulfate |
US20080308192A1 (en) | 2003-12-24 | 2008-12-18 | Arcelor France | Hydroxysulfate Surface Treatment |
JP2010202960A (en) * | 2009-03-06 | 2010-09-16 | Jfe Steel Corp | Zinc-base-plated steel sheet onto the surface of which molten metal hardly deposits |
Non-Patent Citations (7)
Title |
---|
Muster et al. Corrosion Science, 46, 2004, 2319-2335. * |
P. Schweitzer. Corrosion of Linings and Coatings. CPC Press, 2006 pp. 437-446. * |
Panchenko et al . Protection of Metals, 37, N4, 2001, pp. 367-384. * |
Philip Schweitzer Corrosion of Lining and Coatings, 2006, p. 437-438. * |
Quintana et al. JCPDS-International Centre for Diffraction Data 1997, pp. 1-9. * |
Ramanauskas et al. 3rd Latin American Region Corrosion Congress, 1998, pp. 1-9. * |
Ramanauskas et al. Corrosion Science 40, N2/3, 1998, pp. 401-410. * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11319631B2 (en) * | 2017-10-12 | 2022-05-03 | Arcelormittal | Metal sheet treatment method and metal sheet treated with this method |
Also Published As
Publication number | Publication date |
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CN102321885A (en) | 2012-01-18 |
JP2012087417A (en) | 2012-05-10 |
CN101784699A (en) | 2010-07-21 |
TW200925320A (en) | 2009-06-16 |
KR101266596B1 (en) | 2013-05-22 |
TWI480423B (en) | 2015-04-11 |
JP2009079291A (en) | 2009-04-16 |
US8221900B2 (en) | 2012-07-17 |
KR20100049627A (en) | 2010-05-12 |
JP5239570B2 (en) | 2013-07-17 |
CA2696567A1 (en) | 2009-03-12 |
CA2784174C (en) | 2013-07-30 |
EP2186925B1 (en) | 2018-08-01 |
EP2186925A4 (en) | 2015-05-27 |
US8623514B2 (en) | 2014-01-07 |
CA2696567C (en) | 2013-07-30 |
JP5522185B2 (en) | 2014-06-18 |
WO2009031699A1 (en) | 2009-03-12 |
KR20120034128A (en) | 2012-04-09 |
TW201309847A (en) | 2013-03-01 |
EP2186925A1 (en) | 2010-05-19 |
US20100255341A1 (en) | 2010-10-07 |
KR101266713B1 (en) | 2013-05-28 |
CA2784174A1 (en) | 2009-03-12 |
TWI398550B (en) | 2013-06-11 |
US20120082845A1 (en) | 2012-04-05 |
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