Direct-on ceramic coating of carbon-rich iron |
|||||||
| 申请号 | US53544174 | 申请日 | 1974-12-23 | 公开(公告)号 | US3923611A | 公开(公告)日 | 1975-12-02 |
| 申请人 | FERRO CORP; | 发明人 | RUDERER CLIFFORD G; | ||||
| 摘要 | A process is disclosed for preparing an iron workpiece containing at least 0.03% by weight carbon for a direct-on, onefire ceramic or enamel coat. A substantially continuous layer of substantially pure iron is electrodeposited on a surface of the carbon-rich iron workpiece from a liquid medium containing iron ions while using the workpiece as a cathode. The polarity of the electrodeposition is then reversed to remove some of the iron deposited and produce an exposed, fissured, textured surface in the pure iron layer. When a ceramic coat is conventionally applied over the fissured surface, it adheres well, even though the iron workpiece may contain appreciable amounts of carbon which normally would prevent such adherence for a direct-on ceramic coat. Optionally, the cathodic deposition of iron may comprise a deposition of a non-porous layer followed by an overlay of porous iron and/or take place from an aqueous medium having an acidic pH. A film of a covering metal such as nickel may also be deposited over the fissured layer prior to depositing the ceramic coat. | ||||||
| 权利要求 | 1. IN A PROCESS FOR THE DIRECT-ON, CERAMIC COATING OF A CARBON-RICH, IRON WORKPIECE, THE IMPROVEMENTS PRIOR TO DEPOSITING THE CERAMIC COAT OF: A. ELECTRODEPOSITING A SUBSTANTIALLY CONTINUOUS LAYER OF SUBSTANTIALLY PURE IRON ONTO SAID CARBON-RICH IRON WORKPIECE FROM A LIQUID MEDIUM CONTAINING IRON IONS WHILE USING THE WORKPIECE AS A CATHODE, AND B. THEN REVERSING THE POLARITY OF THE ELECTRODEPOSIT TO REMOVE SOME OF THE DEPOSITED IRON AND PRODUCE AN EXPOSED, FISSURED SURFACE IN SUBSTANTIALLY CONTINUOUS LAYER. 2. The process of claim 1 including applying a film of a covering metal onto said fissured surface. 3. The process of claim 2 in which said covering metal is nickel. 4. The process of claim 2 in which said covering metal is selected from the group consisting of nickel, cobalt, copper, and manganese. 5. The process of claim 1 in which said iron workpiece contains at least 0.03% by weight of carbon. 6. The process of claim 1 in which said iron workpiece is cold rolled steel. 7. The process of claim 1 in which said liquid medium is an aqueous solution of a water-soluBle, ionizable iron compound. 8. The process of claim 1 in which said liquid medium is an aqueous solution of a water-soluble, ionizable iron compound and has an acidic pH to provide a metal etch simultaneously with said metal removal. 9. The process of claim 1 in which step a electrodeposits substantially pure iron on said workpiece in an amount of about 5 grams per square foot to about 20 grams per square foot. 10. The process of claim 1 in which step b removes from said deposited layer an amount of about 1 gram per square foot to about 10 grams per square foot. 11. The process of claim 1 in which step a comprises first electrodepositing a non-porous layer of substantially pure iron, and then electrodepositing thereover a porous layer of substantially pure iron. 12. The process of claim 1 in which step a comprises first electrodepositing a non-porous layer of substantially pure iron at a current density of about 10 amperes per square foot to about 40 amperes per square foot, and then electrodepositing thereover a porous layer of substantially pure iron at a higher current density of about 40 amperes per square foot to about 100 amperes per square foot. 13. The process of claim 1 in which step a comprises first electrodepositing a substantially non-porous layer of substantially pure iron at a first current density, and then electrodepositing thereover a more porous layer of substantially pure iron at a second and higher current density. 14. THE PROCESS FOR PREPARING AN IRON WORKPIECE CONTAINING AT LEAST 0.03% BY WEIGHT OF CARBON FOR A DIRECT-ON CERAMIC COATING WITHOUT THE USE OF AN INTERMEDIATE CERAMIC GROUND COAT, COMPRISING: A. ELECTRODEPOSITING ONTO SAID SAID WORKPIECE A DENSE, NON-POROUS LAYER OF SUBSTANTIALLY PURE IRON IN AN AMOUNT OF ABOUT 2 GRAMS PER SQUARE FOOT TO ABOUT 12 GRAMS PER SQUARE FOOT FROM AN AQUEOUS ELECTROPLATING BATH CONTAINING IRON IONS, WHILE USING THE WORKPIECE AS A CATHODE, B. ELECTRODEPOSITING OVER SAID DENSE LAYER A POROUS LAYER OF SUBSTANTIALLY PURE IRON IN AN AMOUNT OF ABOUT 2 GRAMS PER SQUARE FOOT TO ABOUT 12 GRAMS PER SQUARE FOOT FROM AN AQUEOUS ELECTROPLATING BATH CONTAINING IRON IONS, WHILE USING THE WORKPIECE AS A CATHODE, C. REVERSING THE POLARITY OF THE ELECTRODEPOSIT TO REMOVE SOME OF THE DEPOSITED IRON IN AN AMOUNT OF ABOUT 1 GRAM PER SQUARE FOOT TO ABOUT 10 GRAMS PER SQUARE FOOT TO PRODUCE AN EXPOSED FISSURED, TEXTURED SURFACE IN THE CONTINUOUS LAYER, AND D. THEN FORMING A CERAMIC COAT ON SAID FISSURED, TEXTURED SURFACE. 15. The process of claim 14 including applying a film of a covering metal onto said fissured surface prior to forming a ceramic coat. 16. The process of claim 15 in which said covering metal is nickel. 17. The process of claim 15 in which said covering is selected from the group consisting of nickel, cobalt, copper, and manganese. 18. The process of claim 14 in which said iron workpiece is cold rolled steel. 19. The process of claim 14 in which the electrodeposition of step a is carried out at a current density of about 10 amperes per square foot to about 40 amperes per square foot, and the electrodeposition of step b is carried out at a higher current density of about 40 amperes per square foot to about 100 amperes per square foot. 20. The process of claim 14 in which forming a ceramic coat comprises depositing a dispersion of ceramic particles on said surface and then firing to fuse the particles and form a ceramic coat. 21. The process of claim 14 in which said aqueous electroplating baths have a pH of about 2 to about 6. 22. The process of claim 14 in which the electrodeposition of step a is carried out at a first current density, and electrodeposition of step b is carried out at a second and higher current density. |
||||||
| 说明书全文 | |||||||
QQ群二维码
意见反馈
意见反馈