EP4223906A1 - Process sequence for the pickling and passivation of steel - Google Patents
Process sequence for the pickling and passivation of steel Download PDFInfo
- Publication number
- EP4223906A1 EP4223906A1 EP22154842.3A EP22154842A EP4223906A1 EP 4223906 A1 EP4223906 A1 EP 4223906A1 EP 22154842 A EP22154842 A EP 22154842A EP 4223906 A1 EP4223906 A1 EP 4223906A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- less
- bath solution
- water
- reaction rinse
- soluble compounds
- 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.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 31
- 238000005554 pickling Methods 0.000 title claims abstract description 11
- 229910000831 Steel Inorganic materials 0.000 title description 6
- 239000010959 steel Substances 0.000 title description 6
- 238000002161 passivation Methods 0.000 title description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 69
- 229910052742 iron Inorganic materials 0.000 claims abstract description 37
- 150000001875 compounds Chemical class 0.000 claims abstract description 34
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 30
- 239000000126 substance Substances 0.000 claims abstract description 16
- 238000006243 chemical reaction Methods 0.000 claims description 38
- 235000021110 pickles Nutrition 0.000 claims description 20
- 239000002253 acid Substances 0.000 claims description 10
- 239000003973 paint Substances 0.000 claims description 8
- 229910052719 titanium Inorganic materials 0.000 claims description 8
- 238000000151 deposition Methods 0.000 claims description 6
- 230000008021 deposition Effects 0.000 claims description 6
- 229910019142 PO4 Inorganic materials 0.000 claims description 5
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims description 5
- 238000004070 electrodeposition Methods 0.000 claims description 4
- 239000011734 sodium Substances 0.000 claims description 4
- DXIGZHYPWYIZLM-UHFFFAOYSA-J tetrafluorozirconium;dihydrofluoride Chemical compound F.F.F[Zr](F)(F)F DXIGZHYPWYIZLM-UHFFFAOYSA-J 0.000 claims description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 claims description 2
- WRAGBEWQGHCDDU-UHFFFAOYSA-M C([O-])([O-])=O.[NH4+].[Zr+] Chemical compound C([O-])([O-])=O.[NH4+].[Zr+] WRAGBEWQGHCDDU-UHFFFAOYSA-M 0.000 claims description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 2
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 claims description 2
- 125000005595 acetylacetonate group Chemical group 0.000 claims description 2
- 150000004649 carbonic acid derivatives Chemical class 0.000 claims description 2
- 229910052750 molybdenum Inorganic materials 0.000 claims description 2
- 150000002823 nitrates Chemical class 0.000 claims description 2
- YOYLLRBMGQRFTN-SMCOLXIQSA-N norbuprenorphine Chemical compound C([C@@H](NCC1)[C@]23CC[C@]4([C@H](C3)C(C)(O)C(C)(C)C)OC)C3=CC=C(O)C5=C3[C@@]21[C@H]4O5 YOYLLRBMGQRFTN-SMCOLXIQSA-N 0.000 claims description 2
- 229910052700 potassium Inorganic materials 0.000 claims description 2
- 239000011591 potassium Substances 0.000 claims description 2
- 229910052708 sodium Inorganic materials 0.000 claims description 2
- 238000007739 conversion coating Methods 0.000 abstract description 17
- 239000000243 solution Substances 0.000 description 36
- 230000015572 biosynthetic process Effects 0.000 description 12
- 239000010936 titanium Substances 0.000 description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 8
- 239000007788 liquid Substances 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 6
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- -1 iron ions Chemical class 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 150000003839 salts Chemical class 0.000 description 5
- 229910052726 zirconium Inorganic materials 0.000 description 5
- 150000007513 acids Chemical class 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 239000008367 deionised water Substances 0.000 description 4
- 229910021641 deionized water Inorganic materials 0.000 description 4
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 4
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- 239000002987 primer (paints) Substances 0.000 description 3
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 2
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 2
- 229910004619 Na2MoO4 Inorganic materials 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 239000000872 buffer Substances 0.000 description 2
- 238000003618 dip coating Methods 0.000 description 2
- 238000007598 dipping method Methods 0.000 description 2
- 239000011737 fluorine Substances 0.000 description 2
- 229910052731 fluorine Inorganic materials 0.000 description 2
- 150000002222 fluorine compounds Chemical class 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 description 2
- 239000011684 sodium molybdate Substances 0.000 description 2
- TVXXNOYZHKPKGW-UHFFFAOYSA-N sodium molybdate (anhydrous) Chemical compound [Na+].[Na+].[O-][Mo]([O-])(=O)=O TVXXNOYZHKPKGW-UHFFFAOYSA-N 0.000 description 2
- JMXKSZRRTHPKDL-UHFFFAOYSA-N titanium ethoxide Chemical compound [Ti+4].CC[O-].CC[O-].CC[O-].CC[O-] JMXKSZRRTHPKDL-UHFFFAOYSA-N 0.000 description 2
- 229910019934 (NH4)2MoO4 Inorganic materials 0.000 description 1
- 229910019985 (NH4)2TiF6 Inorganic materials 0.000 description 1
- 229910019979 (NH4)2ZrF6 Inorganic materials 0.000 description 1
- 229910003208 (NH4)6Mo7O24·4H2O Inorganic materials 0.000 description 1
- QGHDLJAZIIFENW-UHFFFAOYSA-N 4-[1,1,1,3,3,3-hexafluoro-2-(4-hydroxy-3-prop-2-enylphenyl)propan-2-yl]-2-prop-2-enylphenol Chemical group C1=C(CC=C)C(O)=CC=C1C(C(F)(F)F)(C(F)(F)F)C1=CC=C(O)C(CC=C)=C1 QGHDLJAZIIFENW-UHFFFAOYSA-N 0.000 description 1
- MIMUSZHMZBJBPO-UHFFFAOYSA-N 6-methoxy-8-nitroquinoline Chemical compound N1=CC=CC2=CC(OC)=CC([N+]([O-])=O)=C21 MIMUSZHMZBJBPO-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910003708 H2TiF6 Inorganic materials 0.000 description 1
- 229910003899 H2ZrF6 Inorganic materials 0.000 description 1
- 229910020491 K2TiF6 Inorganic materials 0.000 description 1
- 229910020148 K2ZrF6 Inorganic materials 0.000 description 1
- 229910007828 Li2ZrF6 Inorganic materials 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910003080 TiO4 Inorganic materials 0.000 description 1
- 229960000583 acetic acid Drugs 0.000 description 1
- 239000012556 adjustment buffer Substances 0.000 description 1
- 150000004703 alkoxides Chemical class 0.000 description 1
- APUPEJJSWDHEBO-UHFFFAOYSA-P ammonium molybdate Chemical compound [NH4+].[NH4+].[O-][Mo]([O-])(=O)=O APUPEJJSWDHEBO-UHFFFAOYSA-P 0.000 description 1
- 239000007853 buffer solution Substances 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 239000013590 bulk material Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 230000005595 deprotonation Effects 0.000 description 1
- 238000010537 deprotonation reaction Methods 0.000 description 1
- NMGYKLMMQCTUGI-UHFFFAOYSA-J diazanium;titanium(4+);hexafluoride Chemical compound [NH4+].[NH4+].[F-].[F-].[F-].[F-].[F-].[F-].[Ti+4] NMGYKLMMQCTUGI-UHFFFAOYSA-J 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005183 environmental health Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 239000012362 glacial acetic acid Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- JEGUKCSWCFPDGT-UHFFFAOYSA-N h2o hydrate Chemical compound O.O JEGUKCSWCFPDGT-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-ZSJDYOACSA-N heavy water Substances [2H]O[2H] XLYOFNOQVPJJNP-ZSJDYOACSA-N 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052755 nonmetal Inorganic materials 0.000 description 1
- 150000002843 nonmetals Chemical class 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-O oxonium Chemical compound [OH3+] XLYOFNOQVPJJNP-UHFFFAOYSA-O 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 238000007639 printing Methods 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000001509 sodium citrate Substances 0.000 description 1
- NLJMYIDDQXHKNR-UHFFFAOYSA-K sodium citrate Chemical compound O.O.[Na+].[Na+].[Na+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O NLJMYIDDQXHKNR-UHFFFAOYSA-K 0.000 description 1
- 239000011775 sodium fluoride Substances 0.000 description 1
- 235000013024 sodium fluoride Nutrition 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- LLZRNZOLAXHGLL-UHFFFAOYSA-J titanic acid Chemical compound O[Ti](O)(O)O LLZRNZOLAXHGLL-UHFFFAOYSA-J 0.000 description 1
- 150000003609 titanium compounds Chemical class 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
- 150000003755 zirconium compounds Chemical class 0.000 description 1
- MFFVROSEPLMJAP-UHFFFAOYSA-J zirconium(4+);tetraacetate Chemical class [Zr+4].CC([O-])=O.CC([O-])=O.CC([O-])=O.CC([O-])=O MFFVROSEPLMJAP-UHFFFAOYSA-J 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
- C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
- C23G1/08—Iron or steel
- C23G1/081—Iron or steel solutions containing H2SO4
-
- 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
- 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
-
- 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
- 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
- C23C22/34—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 containing fluorides or complex fluorides
-
- 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
- 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
- C23C22/40—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 containing molybdates, tungstates or vanadates
- C23C22/44—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 containing molybdates, tungstates or vanadates containing also fluorides or complex fluorides
-
- 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
- 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
- C23C22/78—Pretreatment of the material to be coated
-
- 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
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G3/00—Apparatus for cleaning or pickling metallic material
- C23G3/02—Apparatus for cleaning or pickling metallic material for cleaning wires, strips, filaments continuously
- C23G3/021—Apparatus for cleaning or pickling metallic material for cleaning wires, strips, filaments continuously by dipping
Definitions
- reaction rinse (2) it is also in the context of the conversion coating formation in the reaction rinse (2) advantageous to prevent the deposition of a phosphate layer so that in a preferred embodiment in the reaction rinse (2), a total of less than 1.0 g/kg, more preferably less than 0.5 g/kg, particularly preferably less than 0.1 g/kg of phosphate ions, in each case calculated as PO4 and based on the bath solution (B), is contained.
- the "contact" of the components with the respective bath solutions in the method according to the invention comprises any such time-limited technical measure due to which the components are wetted with the particular bath solution.
- These measures include dipping, spraying, printing and/or coating with the particular bath solution, but are not limited to these options.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Treatment Of Metals (AREA)
Abstract
Description
- The present invention relates to a method for the wet-chemical pretreatment of a plurality of iron components in series encompassing a pickling step and a subsequent conversion coating each based on aqueous sulfuric acid bath solutions wherein the conversion coating bath comprises water-soluble compounds of the elements Zr and/or Ti as well as at least one water-soluble compound of the element Mo.
- For various industries, such as the parts engineering sector, iron components, in particular steel components, such as radiators, are processed and produced. During production, these components are pickled, and a conversion coating is applied thereafter. For this purpose, the components pass through established production lines having a particular sequence of various dipping baths, which are adapted to the chemical composition of the iron components. To avoid flash rust formation on steel components in a multi-step process sequence of pickling and conversion coating it has proven advantageous to apply an alkaline rinse directly after the acidic pickling step before applying the conversion coating. However, such a multi-step process sequence adds complexity, consumes additional chemicals, and requires more efforts in wastewater management also due to precipitates of iron. On the other hand, the formation of a homogeneous blueish iridescent conversion coating is oftentimes already impaired at the outset of flash rust formation. Therefore, there still exists a demand for a lean and resource-saving process sequence for the pickling and conversion coating of iron components that effectively reduces red rust formation and establishes a homogeneous conversion coating that promotes adhesion to subsequently applied paints such as powder paints or electrolytic or autophoretic dip coatings.
- It has now surprisingly been found that a plurality of iron components in series, in which each of the iron components, in immediate succession, first passes through a pickle and then a reaction rinse can be successfully protected against red rust formation with a homogeneous blueish iridescent passivation layer provided that the reaction rinse takes place by contacting each iron component with an aqueous sulfuric acid bath solution having a pH of no less than 1.0 comprising water-soluble compounds of the elements Zr and/or Ti in an amount sufficient to form a conversion coating as well as water-soluble compounds of the element Mo.
- In a first aspect, the invention therefore relates to a method for the wet-chemical pretreatment of a plurality of iron components in series, in which each of the iron components, in immediate succession, first passes through a pickle (1) and then a reaction rinse (2), characterized in that
- i) the pickling (1) takes place by being brought into contact with an aqueous sulfuric acid bath solution (A) having a pH of less than 1.0; and
- ii) the reaction rinse (2) takes place by being brought into contact with an aqueous sulfuric acid bath solution (B) having a pH of no less than 1.0, which contains
- a) a total of at least 0.020 g/kg of water-soluble compounds of the elements Zr and/or Ti, in each case based on the respective elements,
- b) a total of at least 0.020 g/kg of water-soluble compounds of the element Mo.
- The pretreatment according to the invention is used to apply an anti-corrosive first coating as a primer for organic coatings. The pretreatment therefore ends in any case with the application of a first organic primer coating (electro dip-coating, powder paint) which itself is not a pretreatment step within the meaning of the present invention.
- A "plurality," as used herein, refers to 2 or more, for example 2, 3, 4, 5, 6, 7, 8, 9, 10, 100, 200, 300, 400 or more.
- The concentrations and amounts of the compounds indicated herein always refer to the respective bath solution, unless explicitly defined differently.
- The method according to the invention relates to wet-chemical pretreatment of a plurality of iron components in series. Pretreatment in series is considered according to the invention to be when a plurality of components is brought into contact with bath solutions for the pickle (1) and/or reaction rinse (2) stored in the system tank, and/or additional wet-chemical treatment steps, the individual components being brought into contact successively and thus at different times.
- A process step is "wet-chemical," if a heterogeneous chemical reaction at the surface of the treated component is induced by contact with a water-based liquid upon which reaction products are dissolved in the water-based liquid, such as a pickling reaction, or upon which reaction educts based on metal-element-based or semi-metal-element-based active compounds contained in the liquid are depleted, such as in the due course of a conversion coating based on oxides and hydroxides formed from dissolved precursor compounds of the elements Zr and/or Ti.
- The iron components used according to the method substantially comprise surfaces of steel and/or iron; preferably more than 60%, particularly preferably more than 80%, more particularly preferably 90% of all metal surfaces of the iron components are surfaces of steel and/or iron. In a particularly preferred embodiment of the method according to the invention, all metal surfaces of the iron components are surfaces of steel and/or iron. The iron component may optionally contain additives of other metals and/or non-metals. These additives may be selected from the group comprising carbon, silicon, chromium, nickel, manganese, molybdenum, tungsten and mixtures thereof; however, the group is not limited thereto.
- In the pretreatment according to the invention, each of the iron components, in immediate succession, first passes through a pickle (1) and then a reaction rinse (2). Within the context of the pretreatment in series, process steps for a component are in "immediate" succession if they are not interrupted by something other than the subsequent wet-chemical pretreatment provided in each case or a rinsing step. In a preferred embodiment the iron components of the series are directly after the pickle (1) and without an intermediate rinsing or drying step transferred to the reaction rinse (2).
- A "rinsing step" in the context of this invention means a process step which is used exclusively for the complete or partial removal of soluble residues, particles and active components that are carried over by adhering to the component from a previous wet-chemical treatment step, from the component to be treated, without metal-element-based or semi-metal-element-based active compounds, which are already consumed merely by bringing the iron surfaces of the component into contact with the rinsing liquid, being contained in the rinsing liquid itself. For example, the rinsing liquid can simply be city water or deionized water or, if necessary, can also be a rinsing liquid which contains surface-active compounds to improve the wettability by means of the rinsing liquid.
- The pickling (1) takes place by being brought into contact with a sulfuric acid bath solution (A) having a pH of less than 1.0. The pH is preferably in the range of 0 to < 1. The bath solution (A) contains water as the main component and sulfuric acid to adjust the desired pH. It is especially preferred that the amount of other strong acids with a pKa value of less than 1.5 is smaller than 0.05 wt.-%, preferably less than 0,01 wt.-% in the bath solution (A).
- The "pH" as used herein corresponds to the negative common logarithm of the hydronium ion activity at 20 °C and can be determined by means of pH-sensitive glass electrodes. The "pKa" as used herein corresponds to the negative common logarithm of the equilibrium constant at 20 °C for the first deprotonation step of the respective acid.
- In the pickling step (1) oxide scale is removed from each iron components of the series as well as iron bulk material dissolved to an extent that ensures a homogeneously surface layer composition. For this purpose, in a preferred method according to the invention, the bath solution (A) of the pickle (1) has a free acid content in points of at least 50, particularly preferably of at least 130 to 200, but preferably of no more than 400.
- The "free acid content" in points is determined according to the consumption of 0.1 N sodium hydroxide solution in milliliters until a pH of 4.0 is reached for a sampled volume of the particular bath solution of 10 ml and a dilution in a ratio of 1:5.
- More specifically, it is preferred that the amount of sulfuric acid in the bath solution (A) of the pickle (1) is at least 3 wt.-%, more preferably at least 5 wt.-%, even more preferably at least 8 wt.-%, but preferably less than 15 wt.-%, more preferably less than 12 wt.-%.
- In a preferred embodiment of the present invention, the pickle (1) contains no more than 80 g/kg, preferably no more than 60 g/kg of iron ions, but preferably at least 1.0 g/kg of iron ions, in each case based on the bath solution (A).
- Since the formation of a passivating film in the pickle (1) would run counter to the formation of a homogenous conversion coating in the reaction rinse (2) it is preferred that the pickle (1) contains no more than 10 g/kg, more preferably no more than 2 g/kg, even more preferably no more than 0.5 g/kg of phosphate ions, in each case calculated as PO4 and based on the bath solution (A).
- Similarly, and for the same reason, it is preferred that the pickle (1) contains less than in total 0.010 g/kg, more preferably less than 0.005 g/kg, of water-soluble compounds of the elements Zr and Ti calculated based on the amount of the respective elements.
- From an environmental health perspective, it is further preferred that the total fluorine content of the pickle (1) is less than 0.050 g/kg, more preferably less than 0.020 g/kg. The total fluorine is determined in a TISAB-buffered aliquot portion of the pickle (1) using a fluoride-sensitive electrode at 20 °C (TISAB: "Total Ionic Strength Adjustment Buffer"), the mixture ratio of buffer to the aliquot portion of the pickle liquor by volume being 1:1. The TISAB buffer is prepared by dissolving 58 g NaCl, 1 g sodium citrate and 50 ml glacial acetic acid in 500 ml deionized water (κ < 1µScm-1), setting a pH of 5.3 using 5 N NaOH and filling to a total volume of 1000 ml, again with deionized water (κ < 1µSCM-1).
- Generally, it is preferred that the amount of other strong acids with a pKa value of below 1.5 but different from watersoluble compounds of the elements Zr and/or Ti is below 0.05 wt.-%, preferably below 0,01 wt.-%.
- The reaction rinse (2) takes place by being brought into contact with a sulfuric acid bath solution (B). The bath solution (B) has a pH which is no lower than 1.0. The bath solution (B) preferably has a pH above 2.0, more preferably above 2.5, even more preferably above 3.0, but preferably a pH of less than 6.0, more preferably of less than 5.0, even more preferably of less than 4.5. The main component of the bath solution (B) is water. The desired pH of the bath solution (B) can be adjusted using acids, in particular a mixture of sulfuric acid and hydrofluoric acid. In various embodiments, this mixture can comprise at least 0.5 wt.%, particularly preferably at least 1 wt.%, sulfuric acid and 1 to 200 ppm, preferably 5 to 50 ppm hydrofluoric acid. It is especially preferred that the amount of other strong acids with a pKa value of below 1.5 but different from watersoluble compounds of the elements Zr and/or Ti is below 0.05 wt.-%, preferably below 0,01 wt.-% in the bath solution (B).
- However, it is also possible to adjust or maintain the pH of the bath solution (B) both by adding sulfuric acid or mixtures comprising sulfuric acid and hydrofluoric acid, as described above, and by means of the entrained bath solution (A). The bath solution (B) of the reaction rinse (2) preferably contains a free acid content in points of at least 3, particularly preferably of at least 10, but preferably of no more than 30.
- For a rapid conversion of the metal surfaces of the components, it is generally preferable for the bath solution (B) to have a minimum content of free fluoride of 5 ppm.
- The amount of free fluoride can be determined potentiometrically by means of a fluoride-sensitive measuring electrode at 20 °C in the relevant acidic aqueous composition after calibration with fluoride-containing buffer solutions without pH buffering. Suitable sources of free fluoride are hydrofluoric acid and the water-soluble salts thereof, such as ammonium bifluoride and sodium fluoride, as well as complex fluorides of the elements Zr, Ti and/or Si, in particular complex fluorides of the element Si.
- The bath solution (B) in the reaction rinse (2) of the method according to the present invention comprises a total of at least 0.020 g/kg of water-soluble compounds of the elements zirconium and/or titanium, in each case based on the respective elements. In various embodiments, the reaction rinse (2) comprises a total of less than 5.0 g/kg, preferably of less than 2.0 g/kg, particularly preferably of less than 1.5 g/kg, but preferably a total of at least 0.100 g/kg, particularly preferably of at least 0.200 g/kg, even more preferably of at least 0.300 g/kg of water-soluble compounds of the elements zirconium and/or titanium, in each case based on the respective elements while the presence of water-soluble compounds of Zr is generally preferred for the formation of a passivating thin conversion coating.
- The water-soluble compounds can all be water-soluble compounds of these metals that are known in the prior art and suitable for this purpose. Within the meaning of the present invention, compounds are "water-soluble" when the solubility thereof in deionized water having a conductivity of no more than 1 µScm-1 at a temperature of 20 °C is at least 1 g/l.
- Suitable and preferred water-soluble compounds of the elements Zr and/or Ti are selected from fluoroacids, preferably selected from hexafluorozirconic acid and/or hexafluorotitanic acid, carbonates, preferably selected from ammonium zirconium carbonate, and/or zirconyl or titanyl compounds, preferably selected from nitrates and/or acetylacetonates.
- Water-soluble titanium compounds which can be used according to the invention include in particular salts and esters of titanic acid, referred to as titanates. For example, H4TiO4 and the corresponding alkoxides such as tetraethyl titanate can be used therefore. In particular, the hexafluoro acids of the titanium H2TiF6 and the water-soluble salts thereof may be used, such as (NH4)2TiF6, Li2TiF6, K2TiF6 and Na2TiF6.
- Water-soluble zirconium compounds which can be used according to the invention include (NH4)2Zr(CO3)2(OH)2, zirconium acetates, zirconium acetylacetonates and hexafluorozirconic acid and the salts thereof such as (NH4)2ZrF6, Li2ZrF6, K2ZrF6 and Na2ZrF6. H2ZrF6 and the water-soluble salts thereof are particularly suitable.
- The bath solution (B) in the reaction rinse (2) of the method according to the present invention also comprises a total of at least 0.020 g/kg of water-soluble compounds of the element Mo. Such amount being required to safeguard a uniform formation of a blueish iridescent conversion coating in the reaction rinse (2). In various embodiments, the reaction rinse (2) comprises a total of less than 5.0 g/kg, preferably of less than 2.0 g/kg, particularly preferably of less than 1.5 g/kg, but preferably a total of at least 0.100 g/kg, particularly preferably of at least 0.200 g/kg, even more preferably of at least 0.300 g/kg of water-soluble compounds of the element Mo.
- Suitable water-soluble compounds of the elements Mo are selected from molybdates, preferably selected from ammonium, sodium and/or potassium molybdates such as (NH4)6Mo7O24·4H2O, (NH4)2MoO4, Na2MoO4·2H2O, or Na2MoO4·10H2O.
- In various embodiments, the reaction rinse (2) may additionally comprise iron ions to accelerate the formation of the conversion coating. In this regard, an amount of at least 0.100 g/kg, in particular at least 1.0 g/kg of iron ions in the bath solution (B) is preferred. However, an amount of iron ions above 10 g/kg does further positively influence the conversion layer formation and is thus not preferred.
- Again, it is also in the context of the conversion coating formation in the reaction rinse (2) advantageous to prevent the deposition of a phosphate layer so that in a preferred embodiment in the reaction rinse (2), a total of less than 1.0 g/kg, more preferably less than 0.5 g/kg, particularly preferably less than 0.1 g/kg of phosphate ions, in each case calculated as PO4 and based on the bath solution (B), is contained.
- The "contact" of the components with the respective bath solutions in the method according to the invention comprises any such time-limited technical measure due to which the components are wetted with the particular bath solution. These measures include dipping, spraying, printing and/or coating with the particular bath solution, but are not limited to these options.
- Bringing the plurality of iron components into contact with the bath solutions in the pickle (1) and/or the reaction rinse (2) can take place over a period of 1 second to 10 minutes, preferably of 5 seconds to 5 minutes, particularly preferably of 10 seconds to 3 minutes.
- In addition, the contact can take place at an elevated temperature of the particular bath solution(s). In various embodiments, the contact takes place at an elevated temperature of the bath solutions (A) and (B). For example, the contact in the pickle (1) and/or in the reaction rinse (2) can take place at a temperature of 5°C to 65°C. In a preferred embodiment, the contact can be carried out at a temperature of 10°C to 60 °C, more preferably 15°C to 55°C, particularly preferably 20°C to 40°C. In this case, it is possible for the pickle (1) and the reaction rinse (2) to be carried out at different temperatures over different periods of time depending on the particular component and on the particular bath solutions (A) and (B).
- In various embodiments, the reaction rinse (2) is followed by a further process step or sequence that establishes an organic primer and/or top coating on the as pretreated plurality of iron components, more preferably without an intermediate phosphatizing step or even more preferably without any additional intermediate wet-chemical treatment step.
- Thus, in a preferred embodiment of this invention after the reaction rinse (2), the iron components undergo a paint deposition, preferably by means of an electrodeposition, more preferably by means of a cathodic electrodeposition.
- In an even more preferred embodiment of the method of this invention after the reaction rinse (2), the iron components do not undergo any additional wet-chemical pretreatment that is a phosphating treatment, preferably do not undergo any additional wet-chemical pretreatment other than a paint deposition, but preferably pass through at least one, particularly preferably at least two rinsing steps prior to the paint deposition.
Claims (12)
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US20150225855A1 (en) * | 2012-08-29 | 2015-08-13 | Ppg Industries Ohio, Inc. | Zirconium pretreatment compositions containing molybdenum, associated methods for treating metal substrates, and related coated metal substrates |
WO2016091703A1 (en) * | 2014-12-09 | 2016-06-16 | Henkel Ag & Co. Kgaa | Integration of light metals into steel pickling and pretreating processes |
US20190249030A1 (en) * | 2016-09-15 | 2019-08-15 | Chemetall Gmbh | Process for corrosion-protecting pretreatment of a metallic surface containing steel, galvanized steel, aluminum, an aluminum alloy, magnesium and/or a zinc-magnesium alloy |
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Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
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US20150225855A1 (en) * | 2012-08-29 | 2015-08-13 | Ppg Industries Ohio, Inc. | Zirconium pretreatment compositions containing molybdenum, associated methods for treating metal substrates, and related coated metal substrates |
WO2016091703A1 (en) * | 2014-12-09 | 2016-06-16 | Henkel Ag & Co. Kgaa | Integration of light metals into steel pickling and pretreating processes |
US20190249030A1 (en) * | 2016-09-15 | 2019-08-15 | Chemetall Gmbh | Process for corrosion-protecting pretreatment of a metallic surface containing steel, galvanized steel, aluminum, an aluminum alloy, magnesium and/or a zinc-magnesium alloy |
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