CA2101772A1 - Manufacturing method for immersion members for use in molten metal baths - Google Patents
Manufacturing method for immersion members for use in molten metal bathsInfo
- Publication number
- CA2101772A1 CA2101772A1 CA002101772A CA2101772A CA2101772A1 CA 2101772 A1 CA2101772 A1 CA 2101772A1 CA 002101772 A CA002101772 A CA 002101772A CA 2101772 A CA2101772 A CA 2101772A CA 2101772 A1 CA2101772 A1 CA 2101772A1
- Authority
- CA
- Canada
- Prior art keywords
- molten metal
- immersion
- sprayed coating
- thermal sprayed
- manufacturing
- 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.)
- Abandoned
Links
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 68
- 239000002184 metal Substances 0.000 title claims abstract description 68
- 238000007654 immersion Methods 0.000 title claims abstract description 54
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 22
- 239000011248 coating agent Substances 0.000 claims abstract description 48
- 238000012545 processing Methods 0.000 claims abstract description 48
- 238000000576 coating method Methods 0.000 claims abstract description 47
- 239000012530 fluid Substances 0.000 claims abstract description 32
- 238000005470 impregnation Methods 0.000 claims abstract description 17
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 claims abstract description 16
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 11
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 10
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 7
- CMMUKUYEPRGBFB-UHFFFAOYSA-L dichromic acid Chemical compound O[Cr](=O)(=O)O[Cr](O)(=O)=O CMMUKUYEPRGBFB-UHFFFAOYSA-L 0.000 claims abstract 4
- 239000012535 impurity Substances 0.000 claims abstract 4
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 claims abstract 4
- 229910052721 tungsten Inorganic materials 0.000 claims description 6
- 239000010937 tungsten Substances 0.000 claims description 6
- 238000000034 method Methods 0.000 claims description 5
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 5
- APUPEJJSWDHEBO-UHFFFAOYSA-P ammonium molybdate Chemical compound [NH4+].[NH4+].[O-][Mo]([O-])(=O)=O APUPEJJSWDHEBO-UHFFFAOYSA-P 0.000 claims description 4
- 235000018660 ammonium molybdate Nutrition 0.000 claims description 4
- 239000011609 ammonium molybdate Substances 0.000 claims description 4
- 229940010552 ammonium molybdate Drugs 0.000 claims description 4
- QYEXBYZXHDUPRC-UHFFFAOYSA-N B#[Ti]#B Chemical compound B#[Ti]#B QYEXBYZXHDUPRC-UHFFFAOYSA-N 0.000 claims description 2
- 239000011651 chromium Substances 0.000 claims 4
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims 1
- LGLOITKZTDVGOE-UHFFFAOYSA-N boranylidynemolybdenum Chemical compound [Mo]#B LGLOITKZTDVGOE-UHFFFAOYSA-N 0.000 claims 1
- 229910052726 zirconium Inorganic materials 0.000 claims 1
- 150000002739 metals Chemical class 0.000 abstract description 8
- 230000007797 corrosion Effects 0.000 abstract description 7
- 238000005260 corrosion Methods 0.000 abstract description 7
- 238000005299 abrasion Methods 0.000 abstract description 3
- 239000002344 surface layer Substances 0.000 abstract description 2
- OFEAOSSMQHGXMM-UHFFFAOYSA-N 12007-10-2 Chemical compound [W].[W]=[B] OFEAOSSMQHGXMM-UHFFFAOYSA-N 0.000 abstract 1
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 27
- 239000011701 zinc Substances 0.000 description 14
- 239000002253 acid Substances 0.000 description 11
- 230000000694 effects Effects 0.000 description 11
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 10
- 229910052725 zinc Inorganic materials 0.000 description 10
- 238000010438 heat treatment Methods 0.000 description 9
- 239000000203 mixture Substances 0.000 description 9
- 238000007747 plating Methods 0.000 description 9
- 239000010410 layer Substances 0.000 description 8
- 238000012360 testing method Methods 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 229910052782 aluminium Inorganic materials 0.000 description 6
- 239000011195 cermet Substances 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 5
- 239000011280 coal tar Substances 0.000 description 5
- 238000007751 thermal spraying Methods 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 238000004017 vitrification Methods 0.000 description 4
- XMCXTGRBAIZQCC-AATRIKPKSA-N (e)-3-[2-[n-acetyl-3-(trifluoromethyl)anilino]-1,3-thiazol-4-yl]prop-2-enoic acid Chemical compound C=1C=CC(C(F)(F)F)=CC=1N(C(=O)C)C1=NC(\C=C\C(O)=O)=CS1 XMCXTGRBAIZQCC-AATRIKPKSA-N 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 3
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 3
- 229910009043 WC-Co Inorganic materials 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000000919 ceramic Substances 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- UVEPOHNXGXVOJE-UHFFFAOYSA-N 3-(2-chlorophenyl)-5-methyl-1,2-oxazole-4-carboxylic acid Chemical compound OC(=O)C1=C(C)ON=C1C1=CC=CC=C1Cl UVEPOHNXGXVOJE-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910000611 Zinc aluminium Inorganic materials 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 235000015393 sodium molybdate Nutrition 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
- 239000000758 substrate Substances 0.000 description 2
- 229910019918 CrB2 Inorganic materials 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- PVNIIMVLHYAWGP-UHFFFAOYSA-N Niacin Chemical compound OC(=O)C1=CC=CN=C1 PVNIIMVLHYAWGP-UHFFFAOYSA-N 0.000 description 1
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 1
- 101100408471 Rhodocybe pseudopiperita ple5 gene Proteins 0.000 description 1
- 229910033181 TiB2 Inorganic materials 0.000 description 1
- 229910007948 ZrB2 Inorganic materials 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- HXFVOUUOTHJFPX-UHFFFAOYSA-N alumane;zinc Chemical compound [AlH3].[Zn] HXFVOUUOTHJFPX-UHFFFAOYSA-N 0.000 description 1
- VWZIXVXBCBBRGP-UHFFFAOYSA-N boron;zirconium Chemical compound B#[Zr]#B VWZIXVXBCBBRGP-UHFFFAOYSA-N 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000008199 coating composition Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 238000005469 granulation Methods 0.000 description 1
- 230000003179 granulation Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- RSMUVYRMZCOLBH-UHFFFAOYSA-N metsulfuron methyl Chemical compound COC(=O)C1=CC=CC=C1S(=O)(=O)NC(=O)NC1=NC(C)=NC(OC)=N1 RSMUVYRMZCOLBH-UHFFFAOYSA-N 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 235000014571 nuts Nutrition 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000007750 plasma spraying Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- -1 tungsten carbides Chemical class 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
- 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
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/18—After-treatment
-
- 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
- C23C2/003—Apparatus
- C23C2/0034—Details related to elements immersed in bath
- C23C2/00342—Moving elements, e.g. pumps or mixers
- C23C2/00344—Means for moving substrates, e.g. immersed rollers or immersed bearings
-
- 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
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
- C23C4/06—Metallic material
- C23C4/067—Metallic material containing free particles of non-metal elements, e.g. carbon, silicon, boron, phosphorus or arsenic
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- Coating By Spraying Or Casting (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A manufacturing method for immersion members for molten metal baths, wherein a thermal sprayed coating comprising 1-50 wt % of tungsten boride, 3-25 wt % of one or more of Ni, Co, Cr, and Mo as a metal phase, and a remainder comprising tungsten carbide and unavoidable impurities, is formed on the surface of a immersion member for use in molten metal baths, and subsequently, impregnation processing is conducted with respect to the thermal sprayed coating in a processing fluid having as a main component thereof chromic acid (H2CrO4 and H2Cr2O7), and subsequently, baking processing is conducted. In accordance with this manufacturing method, a surface layer possessing fine microstructure and high bond strength not conventionally available is provided, and it is possible to manufacture a superior immersion member for use in molten metal baths which has superior resistance to corrosion, resistance to corrosive peeling, and resistance to abrasion, and to which metals do not easily adhere.
A manufacturing method for immersion members for molten metal baths, wherein a thermal sprayed coating comprising 1-50 wt % of tungsten boride, 3-25 wt % of one or more of Ni, Co, Cr, and Mo as a metal phase, and a remainder comprising tungsten carbide and unavoidable impurities, is formed on the surface of a immersion member for use in molten metal baths, and subsequently, impregnation processing is conducted with respect to the thermal sprayed coating in a processing fluid having as a main component thereof chromic acid (H2CrO4 and H2Cr2O7), and subsequently, baking processing is conducted. In accordance with this manufacturing method, a surface layer possessing fine microstructure and high bond strength not conventionally available is provided, and it is possible to manufacture a superior immersion member for use in molten metal baths which has superior resistance to corrosion, resistance to corrosive peeling, and resistance to abrasion, and to which metals do not easily adhere.
Description
~101772 SPECIFICATION
MANUFACTURING METHOD FOR I~MERSION MEMBERS
FOR USE IN MOLTEN ~ETAL BATHS
Technical Field The present invention relates to a manufacturing method for immersion members for use in immersion over long periods in a high temperature molten metal bath ~uch as one of mol~en zinc, molten aluminum, molten tin, and the like. In particular, the present invention relates to a manufacturing method fo~
immersion members for use in molten metal baths in molten zinc plating production lines, molten aluminum plating production lines, molten tin plating production lines, or the like; for example, sink rolls and support rolls which are used in an immersed ~tate in a molten zinc plating bath or a molten aluminum plating bath.
Background Art It is apparent that a resistance to corrosion resulting from molten metals is in great demand with respect to immersion members which can be used over a long period of time in an immersed state in high temperature molten metal baths such as one of molten zinc, molten aluminum, or molten tin, or the like.
In particular, in sink rolls and 3upport rolls, it has been desirable not merely that resi~tance to corro3ion resulting from molten metals be present, but also that abrasion resulting from the contact between the roll and the substrate to be plated, such as a steel plate or the like, which is immersed in the bath, be unlikely to occur, and that adhesion of metals also be 21~1772 unlikely to occur.
When metal adhesion occurs on immersion rolls such as sink rolls, 3upport rolls or the like, damage is caused to the substrate to be plated, or to the plating ~urface of the steel plate or the like, which is guided by these rolls and immersed in the bath. Furthermore, for this reason, immersion rolls such as sink rolls and support rolls have become unfit for use.
Conventionally, in response to these varying demands, immersion members having various cermet materials thermal sprayed thereon have been developed and used; however, such members are as yet insuffici2nt. ~or example, a WC-Co cermet thermal sprayed coating is used as an immersion member for use in molten metal baths; however, such a member is insufficient from the point of view of molten metal corrosion resistance.
Furthermore, the above-described demands have become more and more pressing in concert with demands for increasing quality of plated products, demands for a reduction in manufacturing costs, and demands for extended service life of immersion rolls.
In response to these demands, the present inventors have previously invented an immersion member for use in molten zinc baths and the like, in which the surface coating of the immersion member itself comprises one or more o~ tungsten carbides, tungsten borides, and molybdenum borides, in addition to Co, and this was disclosed in Japanese Patent Application Hei 1-231293 (Japane~e Patent Application, Laid-Open No. ~ei 3-94048, laid open date: April 18, 1991), Corrosion resistance of the immersion member with respect to molten metal baths was achieved by means of this invention; however, there was a problem in that corrosive peeling occurred during use over a
MANUFACTURING METHOD FOR I~MERSION MEMBERS
FOR USE IN MOLTEN ~ETAL BATHS
Technical Field The present invention relates to a manufacturing method for immersion members for use in immersion over long periods in a high temperature molten metal bath ~uch as one of mol~en zinc, molten aluminum, molten tin, and the like. In particular, the present invention relates to a manufacturing method fo~
immersion members for use in molten metal baths in molten zinc plating production lines, molten aluminum plating production lines, molten tin plating production lines, or the like; for example, sink rolls and support rolls which are used in an immersed ~tate in a molten zinc plating bath or a molten aluminum plating bath.
Background Art It is apparent that a resistance to corrosion resulting from molten metals is in great demand with respect to immersion members which can be used over a long period of time in an immersed state in high temperature molten metal baths such as one of molten zinc, molten aluminum, or molten tin, or the like.
In particular, in sink rolls and 3upport rolls, it has been desirable not merely that resi~tance to corro3ion resulting from molten metals be present, but also that abrasion resulting from the contact between the roll and the substrate to be plated, such as a steel plate or the like, which is immersed in the bath, be unlikely to occur, and that adhesion of metals also be 21~1772 unlikely to occur.
When metal adhesion occurs on immersion rolls such as sink rolls, 3upport rolls or the like, damage is caused to the substrate to be plated, or to the plating ~urface of the steel plate or the like, which is guided by these rolls and immersed in the bath. Furthermore, for this reason, immersion rolls such as sink rolls and support rolls have become unfit for use.
Conventionally, in response to these varying demands, immersion members having various cermet materials thermal sprayed thereon have been developed and used; however, such members are as yet insuffici2nt. ~or example, a WC-Co cermet thermal sprayed coating is used as an immersion member for use in molten metal baths; however, such a member is insufficient from the point of view of molten metal corrosion resistance.
Furthermore, the above-described demands have become more and more pressing in concert with demands for increasing quality of plated products, demands for a reduction in manufacturing costs, and demands for extended service life of immersion rolls.
In response to these demands, the present inventors have previously invented an immersion member for use in molten zinc baths and the like, in which the surface coating of the immersion member itself comprises one or more o~ tungsten carbides, tungsten borides, and molybdenum borides, in addition to Co, and this was disclosed in Japanese Patent Application Hei 1-231293 (Japane~e Patent Application, Laid-Open No. ~ei 3-94048, laid open date: April 18, 1991), Corrosion resistance of the immersion member with respect to molten metal baths was achieved by means of this invention; however, there was a problem in that corrosive peeling occurred during use over a
2 ~ 2 long period of time.
In general, cracks and micropores are present in a thermal sprayed coating. During use of an immersion member in a molten metal bath over a long period of time, the molten metal penetrates to the interior of the thermal sprayed layer through these crack~ and micropores and breaks down the thermal sprayed coating, corroding this thermal sprayed coating from below the surface, so that a phenomenon is noted in which the thermal sprayed coating peels away. This is termed corrosive peeling.
In order to solve this problem, the present inventors have tested immersion members in which the cracks and micropores present in the thermal sprayed coating are filled~with coal tar however, under the conditions of high temperature present in the molten metal baths, the organic substances present in the coal tar broke down and became gassified, and for this reason, the quality of the thermal sprayed coating was deteriorated, so that an immersion member having a long service life could not be obtained. Furthermore, the gas produced by the breakdown of the organic substances in the molten metal bath produced undesirable effects.
Furthermore, in order to avoid this phenomenon, an attempt was made to subject the immersion member to heat processing immediately prior to use in the molten metal bath after filling the cracks and micropores of the thermal sprayed coating of the i~mer~ion member for use in molten metal baths with coal tar; however, gas was produced by the breakdown of the organic substances contained in the coal tar during heat proceRsing, and for this reason~ micropitting was produced, and the coal tar filling material itself was lost, so that the 2~1772 de3irable properties could not be obtained.
Disclo~ure of the Invention In order to solve the problems described above, the present inventors have conducted extensive research as described above, and as a result of this research, have arrived at the present invention.
First, an important feature of the present invention is the addition, in the thermal sprayed coating composition, of tungsten borides (WB and the like), the production of a Cr203-B203 system glass in at least the cracks and micropores, by means of an oxidation reaction with H2CrO4, or the like, and the formation of a fine and strong thermal sprayed pore-sealing layer using this effect. In accordance with the present invention, it is possible to obtain a superior immersion member for use in molten metals which is provided with a fine and strong surface film layer not found in the conventional art.
Hereinbelow, the present invention will be explained in detail.
Conventionally, a WC-Co cermet was employed in immersion members for use in molten metal baths; however, a~ a result of the research of the present inventors, it was determined that, in addition to WC, WB is superior from the point of view of corroYion reYi~tance in molten metal. Next, it wa~ determined that WB has a higher coefficient of thermal expan~ion and that the re~lting thermal sprayed coating has a stronger thermal shock resistance than that of WC. Furthermore, it was determined that in an oxidizing atmosphere, borides form B203 on the surface thereof, and that at high temperatures, a portion of this Bz03 is volatilized; however, a certain amount remains on the surface.
Furthermore, the present inventors have determined that it is possible to obtain a superior coating when a thermal spraying material consisting of a cermet in which WC and WB are combined with at least one of Ni, Co, Cr, and Mo, or a thermal spraying material consisting of WC and WB which are coated with Ni, Co, or the like, or a thermal qpraying material consisting of WC and WB which are agglomerated with at least one of Ni, Co, Cr, and Mo, and are subjected to granulation, and sint~ring in a neutral atmosphere, is subjected to thermal spray by a high-velocity oxygen fuel gun method or a plasma spraying method.
Furthermore, WB-WC is superior to WC in molten metal wettability, so that adhesion is unlikely to occur with respect to, for example, molten zinc. However, it was discovered that when the amount of WB added becomes large, satisfactory thermal spraying becomes difficult in a standard atmosphere.
Accordingly, it is preferable that the limitation on the amount of WB contained in the thermal sprayed coating be set to less than 50 weight %. Furthermore, when the amount thereof is too small, the desired effects cannot be realized. Accordingly, the amount of WB contained should be within a range of 1-50 weight %. It is more preferable that the amount contained be within a range of 10-40 wt %.
The reason for the addition of at least one of Ni, Co, Cr, and Mo as a metal phase is to increase resistance to peeling, and to increase hardness, so that superior layer may be obtained. The amount contained of at least one of Ni, Co, Cr, 2~1772 and ~o should preferably be within a range of 3-25 wt %. At amounts of less than 3 wt %, no cermet effects can be obtained.
Furthe~more, when the metal phase exceeds 25 wt %, the effect of adding ceramics which are WC, WB or the like is lost. If at least one of Cr and Mo is added in an amount of less than 15 wt ~, it is possible to improve the molten metal corrosion resistance of the metal phase. It is therefore necessary to limit the total amount of Ni, Co, Cr, and Mo to less than 25 wt %.
The immersion member for use in molten metal baths i5 subjected to surface polishing after thermal spraying; in the manufacturing method of the present invention, it is possible to conduct final polishing after thermal spray coating, prior to processing fluid impregnation processing, or after baking processing. A strong acid solution in which chromic acid comprises the main component is used as the processing fluid.
In order to conduct the impregnation of the processing fluid into the thermal sprayed coating, it is possible to immerse the member for use in molten metal baths, having formed thereon the thermal sprayed coating, into the processing fluid, or to brush the processing fluid onto the thermal sprayed coating formed on the surface of the member for use in molten metal baths. By means of the impregnation processing, the processing fluid penetrates the cracks and micropores, and it is thus possible to fill these cracks and micropores. Next, by means of the initial heating during baking, the chromic acid ~H2CrO4 and ~2Cr207) present in the processing fluid within the cracks and micropores is converted to CrO3, and a filling of these ~racks and micropores results. The chromic acid solution is desicc~ted by means of the heating, and the moi~ture component thereof is removed; however, if heating is continued, in the vicinity of 200 C , molten CrO3 (chromic acid anhydride) results, and it is possible to conduct CrO3 molten salt processing in the thermal ~prayed coating. The thermal ~prayed coating in contact with this is oxidized, and the CrO3 i9 finely bonded with the thermal sprayed coating. That is to say, by means of the reaction using CrO3, the CrzO3 which is formed and the inner surfaces of the cracks and micropores are chemically bonded, and a fine ceramic-filled thermal sprayed coating is formed. The baking temperature should preferably be greater than 400 C , at which temperature Cr203 conversion can be sufficiently conducted, and less than 500 C ; at these temperatures, almost all CrO3 is converted to CrzO3.
Furthermore, it has been determined that the reason that the immersion member produced in accordance with the present invention exhibits superior corrosion resistance with respect to molten metals is that, after the impregnation processing with processing fluid and baking processing, the borides, such as WB
and the like, which are present in the thermal coating sprayed coating are finely and strongly bound with CrzO3.
In particular, in the present invention, the vitrification reaction of the B203 produced by the oxidation of the borides present in the thermal sprayed coating and the CrO3 i~ important. That is to say, thé vitrification of B203 beginQ
at a temperature of approximately 300 C during heating; however, at this temperature, CrO3 becomes a molten oxide, and the vitrified Bz03 and the CrO3, which has become a molten oxide, oxidize the surface of the thermal sprayed coating and the layer 2 ~ 7 2 within the cracks and micropores, Yo that fine fusion occurs so as to produce a CrO3-Cr203-B203 glass substance. Furthermore, when heating is conti~ued and the temperature reaches a level above 400 C , the CrO3 is converted to Cr203 and Rolidifies completely however, the B203 component becomes softer, a portion thereof reacts with the Cr203, becomes more finely bound thereto, and the cracks and micropores are filled. The melting point of B203 iS
approximately 450C .
Accordingly, the combination of the thermal sprayed coating and the processing of the present invention should be termed "glass sealing", and the oxide bonds between the thermal sprayed coating and CrO3, and the bond resulting from vitrification of CrO3 and B203 produce combined function to provide a strong and complete crack-and-micropore-filling effect, as well as an effect of an increase in layer bonding, are exhibited. Furthexmore, no volatilization or combustion of the moisture component or alcohol component occurs during the thermal reaction (in the present invention, a dehydration reaction occurs; however, the moisture component is removed prior to the formation of molten CrO3), and there is no formation of micropitting during heating. For this reason, it is thought that a fine and strong surface layer can be formed.
Furthermore, heating to a temperature in excess of 500 C
produces strain or residual stress in immersion members for use in molten metal baths, so that such heating is not preferable.
AS a result of the above, it iR recommended that the heating temperature during baking processing be within a range of 400C to 500C .
Furthermore, a strongly acidic fluid comprising primarily chromic acid is used as the impregnation processing fluid of the present invention; and the addition of Na+ and K~ ions may improve the permeability of this fluid and apply the solubility of the metallic oxides on the surface of the layer to B203, a small amount of the salts thereof may be added. For example, a small amount of sodium hydroxide (NaOH) or potassium hydroxide (KOH) may be added.
Furthermore, it is possible to add sodium molybdate or ammonium molybdate, or both sodium molybdate and ammonium molybdate, to the processing fluid 3. By means of this, the vitrification described above is improved, and furthermore, as a result of the presence of Mo~3, it is possible to obtain a finer and stronger bonding and diminution effect of micropores and increa~ing fineness of layer microstructures. Thi~ is thought to occur because the components filling the cracks or micropores form a Cr203-B203-MoO3-borate system compound (for example, Na2B407 )-Furthermore, it lS also possible to blend a water-soluble coating agent; however, in this case, an oxidation reaction is carried out by mean~ of chromic acid, so that such an agent should be blended immediately prior to the use thereof in the impregnation processing.
In order to increase the reliability of the coating and strengthening effects of the thermal sprayed coating resulting from the manufacturing method of the present in~ention, it is also possible to repeat the cycle of the processing fluid impregnation processing and baking processing two or more times.
2 i 0 1 7 7 2 Best Mode for Carrying Out the Invention ~ ereinbelow, an embodiment of the present invention will be explained.
Embodiment I
A plurality of metal plates conforming to American Iron and Steel Institute standard AISI 316 (corresponding to the JIS
standard SUS 316~ having a thickness of 5 mm, a width of 30 mm and a length of 100 mm were prepared, and on one side of each metal plate, a thermal sprayed coating was formed by means of a high velocity oxygen fuel gun method, and as shown in Table 1, metal plates having formed thereon thermal sprayed coating having the compositions a-k, o, p, q, and r were produced. The compositions of the thermal sprayed coating formed on the sample metal plate surfaces are shown in Table 1. The compositions having the reference letters a-k fulfill the conditions of the present invention. The compositions referenced o and p do not fulfill the conditions of the present invention and are presented as Comparative Examples. The sample metal plates referenced q and r are Conventional Examples corresponding to ~tandard conventional products; they employ WC~Co system cermet thermal sprayed coating.
Next, a3 shown in Table 2, impregnation processing in proces3ing fluid and baking processing were conducted on the sample metal plate~ prepared a~ described above, and a molten zinc bath immersion test was conducted. In concert with this, a molten zinc immersion test was conducted with respect to the sample metal plates which had not been subjected to impregnation processing in processing fluid or baking processing, and 11 `
comparison was made with the examples of the present invention.
The plating bath employed in the test was a zinc aluminum (Zn-Al) plating bath containing 3% aluminum. In this test, each sample metal plate was continuously immer~ed in this plating bath, and the bath temperature was maintained at 500 C ; the state of the thermal sprayed coating of each sample metal plate was then visually evaluated. As a result of this evaluation, those plates which exhibited no corrosive peeling even after a period of 30 days of continuous immersion are indicated by the designation ~, plates which exhibited no corrosive peeling after 10 days of continuous immersion but which exhibited corrosive peeling after 15 days of continuous immersion are indicated by the designation O , while plates which exhibited corrosive peeling after a period of 10 days of continuous immersion are indicated by the designation ~ .
In Table 2, Examples 1-28 correspond to examples of the present invention, while Comparative Examples 31-42 are examples having thermal sprayed coating, identical to those of 1-28, which were not subjected to impregnation processing in the processing fluid or to baking procPssing. As is clear from the results shown in the Table, even immersion members possessing thermal sprayed coating having identical compositions did not have long service lives if not subjected to impregnation processing in the processing fluid and baking processing.
Furthermore, even if impregnation proces~ing in the processing fluid and baking processing were conducted with respect to immersion members having a conventional WC-Co cerme~ thermal sprayed coating formed thereon, satisfactory effects could not be obtained, as shown by Comparative Examples 45 and 46.
~0~772 Furthermore, as is clear from Comparative Examples 43 and 44, in cases in which the metal phase of the thermal sprayed coating was 2 wt % and 3~ wt ~, these examples were unacceptable in spite of the fact that WB was contained in an amount of lO wt %.
This was found to be so because, in the case in which the metal phase is too small, the caramic material peels easily away from the thermal sprayed coating, while when the metal phase is too large, the metal phase is corroded by the molten metal.
From the above Examples, Comparative Examples, and Conventional Examples, it was found that the effects of the present invention are great.
Industrial ~pplicability As stated above, the manufacturing mPthod for immersion members for use in molten metal baths in accordance with the present invention i5 capable of producing immersion members for use in molten metal baths which possess corrosion resistance with respect to molten metals, have superior resistance to corrosive peeling, have superior resistance to abrasion, have a long service life, have superior wettability with respect to molten metals, and exhibit little metal adhesion, so that such members are extremely useful in industry.
21 ~1772 Table l R :
~ . Metal-Phase e Ceramic Composition (wt %) r Composition (wt %) C
WB CrB2 Other WCCo Ni Mo Cr . ~ (W2B5) Borides _ a 10 _ _ ~n- 10 _ _ _ Used b 10 MoB 3 der 10 _ 3 in c 20 _ _ ~nd~---_ 13 _ _ Composi- Embodi- d 20 5 ZrB2 5 der 12 _ _ tion mentse 20 = TiB2 10 = 11 _ _ 5 of of f 2 0 _ MoB 2 5 der 8 _ 5 _ Thermal Present g 20 _ _ trhdn- 5 7 _ Sprayed Inven- h 30 = = 10 3 5 Coating tion i 3 0 5 _ der _ 12 3 5 _ 30 5TiB2 5 tmdn- 12 5 3 k 40 _ . ._ _ ~3~in- 12 _ - _ C~pa- O 10 _ _ R~i3~- 2 _ _ rative ~ . der _ _ E~ple5 P 10 _ ....... __ ~_ 35 _ 3 _ Cc~n- ~ _ _ _ Ranain- 10 _ _ to~ r = = ~ d~ 12 _ _ 5 ote l: Thermal spraying on one surface of an AISI316 sample having dimensions of 5mm X 30 mm X lOO mm ote 2: In the Table, (W2Bs) indicates that a small amount of W2Bs is contained in the WB.
2 ~ 7 7 2 Table 2 _ThermalImpregnation Baking Molten Zn No.Sp~ed Processing Proces- Bath CoatingCom~Fluid sing Immersion sition(froc Test 1 a 30~ Chrrdc ACid 450C, Ba~ g (~
_ 30 mi~ tes _ _ 2 a30~ Chmoie Aeid, 2i 450C, Baki~ (~
di~sn ~1~3ate MiXn~re 30 mirlutes _
In general, cracks and micropores are present in a thermal sprayed coating. During use of an immersion member in a molten metal bath over a long period of time, the molten metal penetrates to the interior of the thermal sprayed layer through these crack~ and micropores and breaks down the thermal sprayed coating, corroding this thermal sprayed coating from below the surface, so that a phenomenon is noted in which the thermal sprayed coating peels away. This is termed corrosive peeling.
In order to solve this problem, the present inventors have tested immersion members in which the cracks and micropores present in the thermal sprayed coating are filled~with coal tar however, under the conditions of high temperature present in the molten metal baths, the organic substances present in the coal tar broke down and became gassified, and for this reason, the quality of the thermal sprayed coating was deteriorated, so that an immersion member having a long service life could not be obtained. Furthermore, the gas produced by the breakdown of the organic substances in the molten metal bath produced undesirable effects.
Furthermore, in order to avoid this phenomenon, an attempt was made to subject the immersion member to heat processing immediately prior to use in the molten metal bath after filling the cracks and micropores of the thermal sprayed coating of the i~mer~ion member for use in molten metal baths with coal tar; however, gas was produced by the breakdown of the organic substances contained in the coal tar during heat proceRsing, and for this reason~ micropitting was produced, and the coal tar filling material itself was lost, so that the 2~1772 de3irable properties could not be obtained.
Disclo~ure of the Invention In order to solve the problems described above, the present inventors have conducted extensive research as described above, and as a result of this research, have arrived at the present invention.
First, an important feature of the present invention is the addition, in the thermal sprayed coating composition, of tungsten borides (WB and the like), the production of a Cr203-B203 system glass in at least the cracks and micropores, by means of an oxidation reaction with H2CrO4, or the like, and the formation of a fine and strong thermal sprayed pore-sealing layer using this effect. In accordance with the present invention, it is possible to obtain a superior immersion member for use in molten metals which is provided with a fine and strong surface film layer not found in the conventional art.
Hereinbelow, the present invention will be explained in detail.
Conventionally, a WC-Co cermet was employed in immersion members for use in molten metal baths; however, a~ a result of the research of the present inventors, it was determined that, in addition to WC, WB is superior from the point of view of corroYion reYi~tance in molten metal. Next, it wa~ determined that WB has a higher coefficient of thermal expan~ion and that the re~lting thermal sprayed coating has a stronger thermal shock resistance than that of WC. Furthermore, it was determined that in an oxidizing atmosphere, borides form B203 on the surface thereof, and that at high temperatures, a portion of this Bz03 is volatilized; however, a certain amount remains on the surface.
Furthermore, the present inventors have determined that it is possible to obtain a superior coating when a thermal spraying material consisting of a cermet in which WC and WB are combined with at least one of Ni, Co, Cr, and Mo, or a thermal spraying material consisting of WC and WB which are coated with Ni, Co, or the like, or a thermal qpraying material consisting of WC and WB which are agglomerated with at least one of Ni, Co, Cr, and Mo, and are subjected to granulation, and sint~ring in a neutral atmosphere, is subjected to thermal spray by a high-velocity oxygen fuel gun method or a plasma spraying method.
Furthermore, WB-WC is superior to WC in molten metal wettability, so that adhesion is unlikely to occur with respect to, for example, molten zinc. However, it was discovered that when the amount of WB added becomes large, satisfactory thermal spraying becomes difficult in a standard atmosphere.
Accordingly, it is preferable that the limitation on the amount of WB contained in the thermal sprayed coating be set to less than 50 weight %. Furthermore, when the amount thereof is too small, the desired effects cannot be realized. Accordingly, the amount of WB contained should be within a range of 1-50 weight %. It is more preferable that the amount contained be within a range of 10-40 wt %.
The reason for the addition of at least one of Ni, Co, Cr, and Mo as a metal phase is to increase resistance to peeling, and to increase hardness, so that superior layer may be obtained. The amount contained of at least one of Ni, Co, Cr, 2~1772 and ~o should preferably be within a range of 3-25 wt %. At amounts of less than 3 wt %, no cermet effects can be obtained.
Furthe~more, when the metal phase exceeds 25 wt %, the effect of adding ceramics which are WC, WB or the like is lost. If at least one of Cr and Mo is added in an amount of less than 15 wt ~, it is possible to improve the molten metal corrosion resistance of the metal phase. It is therefore necessary to limit the total amount of Ni, Co, Cr, and Mo to less than 25 wt %.
The immersion member for use in molten metal baths i5 subjected to surface polishing after thermal spraying; in the manufacturing method of the present invention, it is possible to conduct final polishing after thermal spray coating, prior to processing fluid impregnation processing, or after baking processing. A strong acid solution in which chromic acid comprises the main component is used as the processing fluid.
In order to conduct the impregnation of the processing fluid into the thermal sprayed coating, it is possible to immerse the member for use in molten metal baths, having formed thereon the thermal sprayed coating, into the processing fluid, or to brush the processing fluid onto the thermal sprayed coating formed on the surface of the member for use in molten metal baths. By means of the impregnation processing, the processing fluid penetrates the cracks and micropores, and it is thus possible to fill these cracks and micropores. Next, by means of the initial heating during baking, the chromic acid ~H2CrO4 and ~2Cr207) present in the processing fluid within the cracks and micropores is converted to CrO3, and a filling of these ~racks and micropores results. The chromic acid solution is desicc~ted by means of the heating, and the moi~ture component thereof is removed; however, if heating is continued, in the vicinity of 200 C , molten CrO3 (chromic acid anhydride) results, and it is possible to conduct CrO3 molten salt processing in the thermal ~prayed coating. The thermal ~prayed coating in contact with this is oxidized, and the CrO3 i9 finely bonded with the thermal sprayed coating. That is to say, by means of the reaction using CrO3, the CrzO3 which is formed and the inner surfaces of the cracks and micropores are chemically bonded, and a fine ceramic-filled thermal sprayed coating is formed. The baking temperature should preferably be greater than 400 C , at which temperature Cr203 conversion can be sufficiently conducted, and less than 500 C ; at these temperatures, almost all CrO3 is converted to CrzO3.
Furthermore, it has been determined that the reason that the immersion member produced in accordance with the present invention exhibits superior corrosion resistance with respect to molten metals is that, after the impregnation processing with processing fluid and baking processing, the borides, such as WB
and the like, which are present in the thermal coating sprayed coating are finely and strongly bound with CrzO3.
In particular, in the present invention, the vitrification reaction of the B203 produced by the oxidation of the borides present in the thermal sprayed coating and the CrO3 i~ important. That is to say, thé vitrification of B203 beginQ
at a temperature of approximately 300 C during heating; however, at this temperature, CrO3 becomes a molten oxide, and the vitrified Bz03 and the CrO3, which has become a molten oxide, oxidize the surface of the thermal sprayed coating and the layer 2 ~ 7 2 within the cracks and micropores, Yo that fine fusion occurs so as to produce a CrO3-Cr203-B203 glass substance. Furthermore, when heating is conti~ued and the temperature reaches a level above 400 C , the CrO3 is converted to Cr203 and Rolidifies completely however, the B203 component becomes softer, a portion thereof reacts with the Cr203, becomes more finely bound thereto, and the cracks and micropores are filled. The melting point of B203 iS
approximately 450C .
Accordingly, the combination of the thermal sprayed coating and the processing of the present invention should be termed "glass sealing", and the oxide bonds between the thermal sprayed coating and CrO3, and the bond resulting from vitrification of CrO3 and B203 produce combined function to provide a strong and complete crack-and-micropore-filling effect, as well as an effect of an increase in layer bonding, are exhibited. Furthexmore, no volatilization or combustion of the moisture component or alcohol component occurs during the thermal reaction (in the present invention, a dehydration reaction occurs; however, the moisture component is removed prior to the formation of molten CrO3), and there is no formation of micropitting during heating. For this reason, it is thought that a fine and strong surface layer can be formed.
Furthermore, heating to a temperature in excess of 500 C
produces strain or residual stress in immersion members for use in molten metal baths, so that such heating is not preferable.
AS a result of the above, it iR recommended that the heating temperature during baking processing be within a range of 400C to 500C .
Furthermore, a strongly acidic fluid comprising primarily chromic acid is used as the impregnation processing fluid of the present invention; and the addition of Na+ and K~ ions may improve the permeability of this fluid and apply the solubility of the metallic oxides on the surface of the layer to B203, a small amount of the salts thereof may be added. For example, a small amount of sodium hydroxide (NaOH) or potassium hydroxide (KOH) may be added.
Furthermore, it is possible to add sodium molybdate or ammonium molybdate, or both sodium molybdate and ammonium molybdate, to the processing fluid 3. By means of this, the vitrification described above is improved, and furthermore, as a result of the presence of Mo~3, it is possible to obtain a finer and stronger bonding and diminution effect of micropores and increa~ing fineness of layer microstructures. Thi~ is thought to occur because the components filling the cracks or micropores form a Cr203-B203-MoO3-borate system compound (for example, Na2B407 )-Furthermore, it lS also possible to blend a water-soluble coating agent; however, in this case, an oxidation reaction is carried out by mean~ of chromic acid, so that such an agent should be blended immediately prior to the use thereof in the impregnation processing.
In order to increase the reliability of the coating and strengthening effects of the thermal sprayed coating resulting from the manufacturing method of the present in~ention, it is also possible to repeat the cycle of the processing fluid impregnation processing and baking processing two or more times.
2 i 0 1 7 7 2 Best Mode for Carrying Out the Invention ~ ereinbelow, an embodiment of the present invention will be explained.
Embodiment I
A plurality of metal plates conforming to American Iron and Steel Institute standard AISI 316 (corresponding to the JIS
standard SUS 316~ having a thickness of 5 mm, a width of 30 mm and a length of 100 mm were prepared, and on one side of each metal plate, a thermal sprayed coating was formed by means of a high velocity oxygen fuel gun method, and as shown in Table 1, metal plates having formed thereon thermal sprayed coating having the compositions a-k, o, p, q, and r were produced. The compositions of the thermal sprayed coating formed on the sample metal plate surfaces are shown in Table 1. The compositions having the reference letters a-k fulfill the conditions of the present invention. The compositions referenced o and p do not fulfill the conditions of the present invention and are presented as Comparative Examples. The sample metal plates referenced q and r are Conventional Examples corresponding to ~tandard conventional products; they employ WC~Co system cermet thermal sprayed coating.
Next, a3 shown in Table 2, impregnation processing in proces3ing fluid and baking processing were conducted on the sample metal plate~ prepared a~ described above, and a molten zinc bath immersion test was conducted. In concert with this, a molten zinc immersion test was conducted with respect to the sample metal plates which had not been subjected to impregnation processing in processing fluid or baking processing, and 11 `
comparison was made with the examples of the present invention.
The plating bath employed in the test was a zinc aluminum (Zn-Al) plating bath containing 3% aluminum. In this test, each sample metal plate was continuously immer~ed in this plating bath, and the bath temperature was maintained at 500 C ; the state of the thermal sprayed coating of each sample metal plate was then visually evaluated. As a result of this evaluation, those plates which exhibited no corrosive peeling even after a period of 30 days of continuous immersion are indicated by the designation ~, plates which exhibited no corrosive peeling after 10 days of continuous immersion but which exhibited corrosive peeling after 15 days of continuous immersion are indicated by the designation O , while plates which exhibited corrosive peeling after a period of 10 days of continuous immersion are indicated by the designation ~ .
In Table 2, Examples 1-28 correspond to examples of the present invention, while Comparative Examples 31-42 are examples having thermal sprayed coating, identical to those of 1-28, which were not subjected to impregnation processing in the processing fluid or to baking procPssing. As is clear from the results shown in the Table, even immersion members possessing thermal sprayed coating having identical compositions did not have long service lives if not subjected to impregnation processing in the processing fluid and baking processing.
Furthermore, even if impregnation proces~ing in the processing fluid and baking processing were conducted with respect to immersion members having a conventional WC-Co cerme~ thermal sprayed coating formed thereon, satisfactory effects could not be obtained, as shown by Comparative Examples 45 and 46.
~0~772 Furthermore, as is clear from Comparative Examples 43 and 44, in cases in which the metal phase of the thermal sprayed coating was 2 wt % and 3~ wt ~, these examples were unacceptable in spite of the fact that WB was contained in an amount of lO wt %.
This was found to be so because, in the case in which the metal phase is too small, the caramic material peels easily away from the thermal sprayed coating, while when the metal phase is too large, the metal phase is corroded by the molten metal.
From the above Examples, Comparative Examples, and Conventional Examples, it was found that the effects of the present invention are great.
Industrial ~pplicability As stated above, the manufacturing mPthod for immersion members for use in molten metal baths in accordance with the present invention i5 capable of producing immersion members for use in molten metal baths which possess corrosion resistance with respect to molten metals, have superior resistance to corrosive peeling, have superior resistance to abrasion, have a long service life, have superior wettability with respect to molten metals, and exhibit little metal adhesion, so that such members are extremely useful in industry.
21 ~1772 Table l R :
~ . Metal-Phase e Ceramic Composition (wt %) r Composition (wt %) C
WB CrB2 Other WCCo Ni Mo Cr . ~ (W2B5) Borides _ a 10 _ _ ~n- 10 _ _ _ Used b 10 MoB 3 der 10 _ 3 in c 20 _ _ ~nd~---_ 13 _ _ Composi- Embodi- d 20 5 ZrB2 5 der 12 _ _ tion mentse 20 = TiB2 10 = 11 _ _ 5 of of f 2 0 _ MoB 2 5 der 8 _ 5 _ Thermal Present g 20 _ _ trhdn- 5 7 _ Sprayed Inven- h 30 = = 10 3 5 Coating tion i 3 0 5 _ der _ 12 3 5 _ 30 5TiB2 5 tmdn- 12 5 3 k 40 _ . ._ _ ~3~in- 12 _ - _ C~pa- O 10 _ _ R~i3~- 2 _ _ rative ~ . der _ _ E~ple5 P 10 _ ....... __ ~_ 35 _ 3 _ Cc~n- ~ _ _ _ Ranain- 10 _ _ to~ r = = ~ d~ 12 _ _ 5 ote l: Thermal spraying on one surface of an AISI316 sample having dimensions of 5mm X 30 mm X lOO mm ote 2: In the Table, (W2Bs) indicates that a small amount of W2Bs is contained in the WB.
2 ~ 7 7 2 Table 2 _ThermalImpregnation Baking Molten Zn No.Sp~ed Processing Proces- Bath CoatingCom~Fluid sing Immersion sition(froc Test 1 a 30~ Chrrdc ACid 450C, Ba~ g (~
_ 30 mi~ tes _ _ 2 a30~ Chmoie Aeid, 2i 450C, Baki~ (~
di~sn ~1~3ate MiXn~re 30 mirlutes _
3 b3096 C~mie Aeid450C, ~ g
4 30~ Chrcmic Aeid, 26 450C, ~id~
S~di~n ~l}~te Mixturo 30 m~r~tes C30~ Cbmnie Acid450C, Bak~
_ _ _ .... _ _ 30 m~l~tes Embodi- 6 c303 Chranie Acid, 296gsoC, Baki~g _ Sodit~ date ~cture30 n~i~tes .
ments 7 c30~ mieAeid, 2~Am- -gSODC Ba~ g ~}1 m ni~n ~l~te ~ixture30 mi~tes of 8 d30t Ch~alLie Acid950C, Ba.lc~
_ . 30 mi~utes Present 9 d30~ Chrcmie Aeid, 2~450C, Bakir~ @~
_ = 30 m~nutes Invention 10 e 3096 Chrcll~ic Aeid gSOC, Ba~cing _ 30 m~tes . _ 11 e3096 Chranic Aeid, 2~gSOC, Baki~ ~) Sodium r~l~a3ate Mixture 30 mi~tes _ .
12 e30~ Chrcmie Aeid, 2i450C, Bakir~
Sodiun ~l~ate, 296 Am-30 min~ltes ~}) mlli~n l~ly}x~ato ~re .
13 f30i Chmnie Aeid 450C, ~ g . 30 minutes 14 f30~ Chrnie Aeid, 2i450C, Ba~ g ~3 _ S~di~n ~ly~date ~e30 mi~lutes f303 Chr~mic Acid, 23 Am- 450C, Bakir~g ~a m ni~n ~l~ate Mixture30 ~utes 16 303 C}~mic Acid 450C, ~aki~
_ 30 m~tes 17 g303 Ch~ ic Acid, 23450C, Bakir~g O
scdiun ~l~ate Mixture30 mir~tes 18 g303 Ch~cmic Acid, 23 Am- 450C, Bak~
~ni~ l~te Mi~cture 30 mi~tes _ 19 g303 Chrcmic Acid, 23450C, E~
Scdiun Mcl~te, 296 Am-30 mir~tes ~3 nmi~ Dl~te ~ixture h303 Chr~mic Acid450C, 8akir~g . . . . 30 mirD~tes 21 h 303 Chrcmic ACid, 23 450C, Bak~
. S~ n l~l~te Mix~re 30 mir~tes .. .__. .
2 2 i303 Chrcmic Acid450C, Ba~cir~g (~
30 oiD~ _ __ 23 i303 Chrcmic Acid, 23 450C, 8a~cing _ _ Scdi~m 1~1~3ate ~ctyre 30 mi~tes (continued) Note 1: The evaluation of the zinc bath immersion test (molten Zn bath containing 3% Al, 500C, an AISI 316 sample tharmal sprayed on one surface and having dimensions of 5 mm X 30 mm X 100 mm) was as follows:
~: No corrosive peeling after 30 daysl immersion 0: No peeling after 10 days, corrosive peeling after 15 days~ immersion ~: Corrosive peeling after 10 days' immersion Table 2 (continued) _ .
ThermalImpregnationBaking Molten Zn No.Sp~edProcessing Proces- Bath ~ting ~ i~ Fluid s~ng Immerslon Embodiments 24 i303 Chranic ACid 450C, ~a~cing _ _ _ _ 30 minutes of Present 25 i30~ChromicAcid, 2~ 450C, Bak~
dium ~l~te Mixture30 mir~tes Invention26 k 30~Chrnic Acid4S0C, ~)cir~ 0 27 k30~ Chrcmic Acid, 2~ 450C, Baking _Sodi~m~l~e ~ure30 minutes 28 k30~ Chmrdc Acid, 2~ Am-450C, 8aking ~) . _ msniu~ l~te Mi~cture 30 minutes Comparative 31 _Prccessina Fluid Prccessin~ O
Examples 32 b r~ ~pr~til inN~ lcirg O
Pr~xessir~r FluidProcessirg 33 c~ ~p~ati~ in ~ a~ O
_ Pr~essir~ Fluid ~
34 d~ ~p~ati~ in ~ ~ O
Prccessi~ FluidPrccessi~
e~ ~p~ation in ~ ~ O
_ Prccessirg FluidPr~cessing 3 6 f~ ~pr~nation in~ ~dng O
P~cessir~ Fluid _Prccess~ng 37 g~ ~p~ticn in ~ ~ O
.Pmcessir~LFluidPrccessinSL
38 h~ ~p~ati~ in ~ ~ O
E~rccessing FluidProcessir~
3 9 i1~ ~pr~pation in~ 33kina O
Prccessim FluidPrccessir~
41 . ~b ~p~tial in . _ _ Prccessing Fluid Prccessir~T
42 k~ ~p~ati~ in ~ ~ina O
Processina Fluid Pmcessir~
a~3 30~ Chr~nic Acid 450C, Ba)cin . _ . 30 nunutes 44 P 30~Chmmic Acid 450C, ~ ~
e . _ 30 mi~es ~1 30~ mic Acid 450C, Bakina . 30 Ir~utes 46 r 30~ Ci~cmic Acid 450C, _ . .. 30 ~uCe~ .
Convention- S1 q ~ ~p~ati~ in ~ ~ ~
.~cessir a Fluid P~e5s~3 _ al Examples 52 r ~ ~a~ion in ~ a~ ~
ccessirg Fluid Prccessir~
Note 1: The evaluation of the zinc bath immersion test (molten Zn bathcontaining 3% A1, 500C, an AISI 316 sample thermal sprayed on one surface and having dimensions of 5 mm X 30 mm X 10,0 mm~ was as follows:
~: No corrosive peeling after 30 days' immersion o: No peeling after 10 days, corrosive peeling after 15 days' immersion ~: Corrosive peeling after 10 days~ immersion
S~di~n ~l}~te Mixturo 30 m~r~tes C30~ Cbmnie Acid450C, Bak~
_ _ _ .... _ _ 30 m~l~tes Embodi- 6 c303 Chranie Acid, 296gsoC, Baki~g _ Sodit~ date ~cture30 n~i~tes .
ments 7 c30~ mieAeid, 2~Am- -gSODC Ba~ g ~}1 m ni~n ~l~te ~ixture30 mi~tes of 8 d30t Ch~alLie Acid950C, Ba.lc~
_ . 30 mi~utes Present 9 d30~ Chrcmie Aeid, 2~450C, Bakir~ @~
_ = 30 m~nutes Invention 10 e 3096 Chrcll~ic Aeid gSOC, Ba~cing _ 30 m~tes . _ 11 e3096 Chranic Aeid, 2~gSOC, Baki~ ~) Sodium r~l~a3ate Mixture 30 mi~tes _ .
12 e30~ Chrcmie Aeid, 2i450C, Bakir~
Sodiun ~l~ate, 296 Am-30 min~ltes ~}) mlli~n l~ly}x~ato ~re .
13 f30i Chmnie Aeid 450C, ~ g . 30 minutes 14 f30~ Chrnie Aeid, 2i450C, Ba~ g ~3 _ S~di~n ~ly~date ~e30 mi~lutes f303 Chr~mic Acid, 23 Am- 450C, Bakir~g ~a m ni~n ~l~ate Mixture30 ~utes 16 303 C}~mic Acid 450C, ~aki~
_ 30 m~tes 17 g303 Ch~ ic Acid, 23450C, Bakir~g O
scdiun ~l~ate Mixture30 mir~tes 18 g303 Ch~cmic Acid, 23 Am- 450C, Bak~
~ni~ l~te Mi~cture 30 mi~tes _ 19 g303 Chrcmic Acid, 23450C, E~
Scdiun Mcl~te, 296 Am-30 mir~tes ~3 nmi~ Dl~te ~ixture h303 Chr~mic Acid450C, 8akir~g . . . . 30 mirD~tes 21 h 303 Chrcmic ACid, 23 450C, Bak~
. S~ n l~l~te Mix~re 30 mir~tes .. .__. .
2 2 i303 Chrcmic Acid450C, Ba~cir~g (~
30 oiD~ _ __ 23 i303 Chrcmic Acid, 23 450C, 8a~cing _ _ Scdi~m 1~1~3ate ~ctyre 30 mi~tes (continued) Note 1: The evaluation of the zinc bath immersion test (molten Zn bath containing 3% Al, 500C, an AISI 316 sample tharmal sprayed on one surface and having dimensions of 5 mm X 30 mm X 100 mm) was as follows:
~: No corrosive peeling after 30 daysl immersion 0: No peeling after 10 days, corrosive peeling after 15 days~ immersion ~: Corrosive peeling after 10 days' immersion Table 2 (continued) _ .
ThermalImpregnationBaking Molten Zn No.Sp~edProcessing Proces- Bath ~ting ~ i~ Fluid s~ng Immerslon Embodiments 24 i303 Chranic ACid 450C, ~a~cing _ _ _ _ 30 minutes of Present 25 i30~ChromicAcid, 2~ 450C, Bak~
dium ~l~te Mixture30 mir~tes Invention26 k 30~Chrnic Acid4S0C, ~)cir~ 0 27 k30~ Chrcmic Acid, 2~ 450C, Baking _Sodi~m~l~e ~ure30 minutes 28 k30~ Chmrdc Acid, 2~ Am-450C, 8aking ~) . _ msniu~ l~te Mi~cture 30 minutes Comparative 31 _Prccessina Fluid Prccessin~ O
Examples 32 b r~ ~pr~til inN~ lcirg O
Pr~xessir~r FluidProcessirg 33 c~ ~p~ati~ in ~ a~ O
_ Pr~essir~ Fluid ~
34 d~ ~p~ati~ in ~ ~ O
Prccessi~ FluidPrccessi~
e~ ~p~ation in ~ ~ O
_ Prccessirg FluidPr~cessing 3 6 f~ ~pr~nation in~ ~dng O
P~cessir~ Fluid _Prccess~ng 37 g~ ~p~ticn in ~ ~ O
.Pmcessir~LFluidPrccessinSL
38 h~ ~p~ati~ in ~ ~ O
E~rccessing FluidProcessir~
3 9 i1~ ~pr~pation in~ 33kina O
Prccessim FluidPrccessir~
41 . ~b ~p~tial in . _ _ Prccessing Fluid Prccessir~T
42 k~ ~p~ati~ in ~ ~ina O
Processina Fluid Pmcessir~
a~3 30~ Chr~nic Acid 450C, Ba)cin . _ . 30 nunutes 44 P 30~Chmmic Acid 450C, ~ ~
e . _ 30 mi~es ~1 30~ mic Acid 450C, Bakina . 30 Ir~utes 46 r 30~ Ci~cmic Acid 450C, _ . .. 30 ~uCe~ .
Convention- S1 q ~ ~p~ati~ in ~ ~ ~
.~cessir a Fluid P~e5s~3 _ al Examples 52 r ~ ~a~ion in ~ a~ ~
ccessirg Fluid Prccessir~
Note 1: The evaluation of the zinc bath immersion test (molten Zn bathcontaining 3% A1, 500C, an AISI 316 sample thermal sprayed on one surface and having dimensions of 5 mm X 30 mm X 10,0 mm~ was as follows:
~: No corrosive peeling after 30 days' immersion o: No peeling after 10 days, corrosive peeling after 15 days' immersion ~: Corrosive peeling after 10 days~ immersion
Claims (5)
1. A manufacturing method for immersion members for use in molten metal baths, wherein a thermal sprayed coating comprising 1-50 wt % of tungsten borides, 3-25 wt % of one or more of Ni, Co, Cr, and Mo as a metal phase, and a remainder comprising tungsten carbide and unavoidable impurities is formed on a surface of an immersion member for use in molten metal baths, and subsequently, an impregnation process in a processing fluid comprising chromic acid (H2CrO4 and H2Cr2O7) as a main component is conducted on said thermal sprayed coating, and subsequently, baking processing is conducted.
2. A manufacturing method for immersion members for use in molten metal baths, wherein a thermal sprayed coating comprising 10-40 wt % of tungsten borides, 3-25 wt % of at least one of Ni, Co, Cr, and Mo as a metal phase, and a remainder comprising tungsten carbide and unavoidable impurities, is formed on a surface of an immersion member for use in molten metal baths, and subsequently, an impregnation process in a processing fluid comprising chromic acid (H2CrO4 and H2Cr2O7) as a main component thereof is conducted with respect to said thermal sprayed coating, and subsequently, baking processing is conducted.
3. A manufacturing method for immersion members for use in molten metal baths, wherein a thermal sprayed coating comprising 1-49 wt % of tungsten borides, 1-30 wt % of one or more of chromium boride, molybdenum boride, zirconium boride, and titanium boride, wherein a total amount of these metal borides is less than 50 wt %, 3-25 wt % of one or more of Ni, Co, Cr, and Mo as a metal phase, and a remainder comprising tungsten carbide and unavoidable impurities is formed on a surface of an immersion member for use in molten metal baths, and subsequently, impregnation processing in a processing fluid having as a main component thereof chromic acid (H2CrO4 and H2Cr2O7 ) is conducted with respect to said thermal sprayed coating, and subsequently, baking processing is conducted.
4. A manufacturing method for immersion members for use in molten metal baths, wherein, in the manufacturing method for immersion members for use in molten metal baths in accordance with one of Claims 1, 2, and 3, said baking processing is conducted at a temperature within a range of 400-500°C.
5. A manufacturing method for immersion members for use in molten metal baths, wherein in the manufacturing method for immersion members for use in molten metal baths in accordance with one of Claims 1 through 4, said processing fluid for thermal sprayed coating impregnation contains at least one of ammonium molybdate and ammonium molybdate.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1231293A JP2553937B2 (en) | 1989-09-06 | 1989-09-06 | Immersion member for molten metal with excellent corrosion and wear resistance |
| PCT/JP1991/001646 WO1993011277A1 (en) | 1991-11-29 | 1991-11-29 | Process for producing immersion member of molten metal bath |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2101772A1 true CA2101772A1 (en) | 1993-05-30 |
Family
ID=25676441
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002101772A Abandoned CA2101772A1 (en) | 1989-09-06 | 1991-11-29 | Manufacturing method for immersion members for use in molten metal baths |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2101772A1 (en) |
-
1991
- 1991-11-29 CA CA002101772A patent/CA2101772A1/en not_active Abandoned
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |