US3713999A - Electrodeposition of chromium - Google Patents
Electrodeposition of chromium Download PDFInfo
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- US3713999A US3713999A US00080220A US3713999DA US3713999A US 3713999 A US3713999 A US 3713999A US 00080220 A US00080220 A US 00080220A US 3713999D A US3713999D A US 3713999DA US 3713999 A US3713999 A US 3713999A
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- selenium
- chromium
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/04—Electroplating: Baths therefor from solutions of chromium
Definitions
- One object of the present invention is to produce a chromium coating which has a large number of microcracks, uniform color of deposit, good cathode efficiency and adequate throwing and covering power.
- Sulphates are often added to chromium electrolytes and a wide range has been suggested but not all proportions are suitable and suitable proportions vary with different electrolyte compositions.
- chromium plating baths containing a fluoride and sulphate a microcracked deposit is obtainable with a high proportion of fluoride in areas of an article where current density is high but on the same article microcracking is not produced on areas of low current density.
- a high fluoride content also will not tolerate the increasing oxidic impurities which occur over a period of use and involves a critical range of sulphate which is impractical to maintain.
- a lower proportion of fluoride does not produce a good deposit. If selenium is included in sufficiently large proportion with a view to facilitating the production of microcracks, a deposit is produced which has an undesirable blue color and the covering power of the deposit over areas of varying current density is reduced. If the proportion of fluoride is reduced and the solution is otherwise suitably adjusted, the deposit tends to have bands of different color across the article.
- the present invention provides a solution which gives a good microcracked deposit of good covering power over areas of varying shape and current density and good uniform color and which maintains these characteristics over a long period with little or no maintenance, using a low proportion of fluoride and an adequate range of sulphate.
- boric acid in chromiufn plating baths has been considered undesirable (e.g. page 179 of Electroplating Laboratory Manual" by R.C. Armet publishedby Robert Draper Limited of, Teddington which states that poor rinsing from a bright nickel solution will result in nickel, boric acid, sulphate and chloride entering the chromium bath, all troublesome impurities resulting in lowering of covering power").
- Our own experience confirms that boric acid is commonly used in nickel plating baths and this results in some boric acid being carried over with the chromium plating baths with detrimental effects, e.g., boric acid added to certain otherwise reasonably satisfactory electrolyte solutions causes loss of microcracks.
- boric acid has never been proposed as an addition to electrolytes for producing microcracked chromium'coating.
- the present invention is based on the discovery that the combination of a high content of boric acid or of a salt giving rise to borate ions (B0,), in combination with selenium ions produces a surprising combination of advantages.
- the boric acid or a salt giving rise to borate ions may be used in quantity from two grams per liter of electrolyte solution up to a saturated solution.
- boric acid or salt makes the electrolyte more tolerant to variation of the CrO /SO, ratios.
- a suitable salt is sodium or potassium perborate or borax.
- the electrolyte solution of the present invention gives a good bright color (less blue), is tolerant to a high proportion of oxides, has good throwing and covering power, good cathode efficiency, even distribution of microcracks, and tolerant to fluoride and wide range of sulphate.
- a solution for use as an electrolyte for electrolytic deposition of chromium comprising an aqueous solution containing chromic acid (CrO boric acid or salt giving borate ions, a fluorine-containing compound, a sulphate-ion-containing compound, and a selenium compound; the selenium compound containing from 0.003 to 0.012, e.g., 0.003 to 0.009 selenium dioxide gram per liter, preferably 0.005 to 0.009; the quantity of CrO being 180 to 250 grams per liter, and the ratio of CrO to fluoride ion is 110 to 320 to 1, preferably 190 to 220 to 1.
- the ratio of sulphate ion to fluoride ion may be 0.64 to 2.56 to l for best microcracked deposit best covering and throwing power.
- the ratio CrO to S0 may be to 250, for best microcracked coating.
- the boric acid may be used in any proportion up to maximum solubility but we normally prefer 10-30 grams per liter.
- the average operating temperature may be to F, preferably l05-115 F.
- the cathode current density may be -200 amps per square foot.
- the period of treatment is normally 6 to 10 minutes.
- a plating time of a minimum 7 minutes at 200 amps/sq.ft. will produce microcracked deposits having cracks of some 700-2000 per linear inch. Deposits of less than 0.00002 inch Cr. surprisingly showed a microporous structure of fine pit-like pores and small cracks that failed to join up as those at greater thickness.
- articles of complex shape can be plated by this process and even in low current density areas and/or low thicknesses of chromium improved corrosion resistance can be found by virtue ofhaving microcracks.
- the invention also provides a combination of additional advantages, viz. wide current density range, wide temperature range, low fluoride concentration, microcracks over the entire plating range at all thicknesses, and ability to operate satisfactorily with fluorinated hydrocarbons in order to suppress chromium fumes and spray.
- a particular example of an electrolyte solution in accordance with this invention consists of:
- Thickness of deposit .00003 inch.
- electrolyte solution of the present invention can be made up as follows:
- Sulphuric acid 0.7 to 2.0, e.g., 0.7-1.0 g/liter.
- CrO to S0 85 to 250 preferably 135-185 for best microcracking.
- CrO to S0 ion plus fluoride ion 45 to 140.
- Sulphate plus fluoride ion to Se ion is 212 to 1780.
- Sulphate to selenium ion is 120 to 1000.
- Fluoride ion to selenium ion is 90 to 320.
- the number of microcracks per inch in the final chromium deposit is 750-2500, preferably 1500-2000.
- the fluorine compound may be hydrofluoric acid and/or its salts; fluoboric acid and/or its salts; fluozirconate, fluoaluminate, fluotitanate, sodium and/or potassium silicofluoride.
- the selenium may be added as selenic acid, or its alkali metal salts, or selenious oxide.
- the solution may also include other agents such as surface active agents and foam depressants.
- the thickness of the microcracked chromium layer may in practice be from 0.00002 to 0.00004 inch.
- An acidic aqueous solution for electrodeposition of chromium in microcracked condition having at least v 700 microcracks per linear inch comprising (a) chromic acid (CrO (b) at least two grams per liter of solution ofa boron containing compound selected from the group consisting of boric acid and water soluble salts thereof giving rise to borate ions, 50) sul hate ions, (d) a fluorine containing compoun and e) a selenium compound.
- a solution as claimed in claim 1 wherein said selenium compound is selenium dioxide present in an amount of at least 0.003 grams/liter solution, the quantity of CrO is 180 to 450 grams per liter and the weight ratio of CrO to fluoride ion is :1 to 266:1.
- Selenium compound at least 0.003 g/liter selenium oxide Boric acid at least 10 g/liter.
- a process of preparing article having a microcracked chromium coating having 700 to 2000 microcracks per linear inch which comprises elec trolytically treating as the cathode an article selected from the group consisting of nickel articles, cobalt articles, nickel-cobalt articles and articles coated with nickel, cobalt or nickel-cobalt in an acidic aqueous solution consisting essentially of (a) 180 to 400 g/liter CrO at least 10 g/liter of a boron containing compound selected from the group consisting of boric acid or salts thereof, sulfate ions present in a weight ratio of CrO to S0,, 100:1 to 180:1, a fluorine containing compound selected from the group consisting of hydrofluoric acid, fluorboric acid, salts of fluorboric acid, fluozirconate, fluoaluminate, fluotitanate, sodium silicafluoride and potassium silicafluoride in an amount providing fluoride to CrO in a weight ratio
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electroplating And Plating Baths Therefor (AREA)
- Chemical Treatment Of Metals (AREA)
Abstract
The invention provides an acidic aqueous solution for electrodeposition of chromium comprising chromic acid (CrO3), at least 2 grams of boric acid or a salt giving rise to borate ions per liter of solution, and sulphate ions.
Description
Q United States Patent 11 1 1111 3,713,999 Law et al. 1 1 Jan. 30, 1973 [54] ELECTRODEPOSITION OF [56] References Cited CHROMIUM UNITED STATES PATENTS [75] Inventors: Malcolm John Law, Dorking; 3 303 H4 2/967 Rom k, 204/51 1 Y anows 1 55 g g Bmmsgmve 3,505,183 4 1970 Seyb etal ..204 51 0 0 3,514,380 5/1970 Tuchewriz .204/51 3,069,333 12/1962 Deyoup .204/51 [73] Ass'gnee' Er (ihegmals 3,340,165 9/1967 Chessin ..204/51 3,418,220 12/1968 R0ggendorf.... .204/41 [22] Filed: Oct. 12, 1970 Primary Examiner-F1 C. Edmundson [21] Appl. No.. 80,220 Att0rneyChristen & Sabol 1301 Foreign Application Priority Data [571 ABSTRACT Oct. 10, 1969 Great Britain ..49,802/69 The inventiofPmvides an i 9 electrodeposltlon of chrom1um compnsmg chr0m1c cid (CrO at least 2 grams of boric acid or a salt 152 US. Cl .204/51 51 Int. Cl. ..C23b 5/06, C23b 5/48 if"? to mate per and p ate10ns. [58] Field of Search ..206/51 10 Claims, No Drawings ELECTRODEPOSITION OF CHROMIUM This invention relates to the electrodeposition of chromium on nickel, cobalt or nickel-cobalt coated metal articles, e.g., chromium on nickel-coated steel articles and chromium or nickel-coated on to coppercoated zinc base alloy articles.
One object of the present invention is to produce a chromium coating which has a large number of microcracks, uniform color of deposit, good cathode efficiency and adequate throwing and covering power.
Numerous difficulties exist in providing an electrolyte solution capable of producing a bright microcracked chromium with good throwing and covering power.
Numerous chemical compounds have been suggested for incorporation with the electrolyte and they generally display some disadvantages.
Thus the addition of fluorides increase cathode efficiency but may produce non-uniform color deposit.
Sulphates are often added to chromium electrolytes and a wide range has been suggested but not all proportions are suitable and suitable proportions vary with different electrolyte compositions.
Suggestions have been made to add selenium compounds to the electrolyte.
In known chromium plating baths containing a fluoride and sulphate a microcracked deposit is obtainable with a high proportion of fluoride in areas of an article where current density is high but on the same article microcracking is not produced on areas of low current density. A high fluoride content also will not tolerate the increasing oxidic impurities which occur over a period of use and involves a critical range of sulphate which is impractical to maintain. A lower proportion of fluoride does not produce a good deposit. If selenium is included in sufficiently large proportion with a view to facilitating the production of microcracks, a deposit is produced which has an undesirable blue color and the covering power of the deposit over areas of varying current density is reduced. If the proportion of fluoride is reduced and the solution is otherwise suitably adjusted, the deposit tends to have bands of different color across the article.
In addition to these problems, difficulties are experienced in maintaining the solution over an extended period of use because the composition of the solution changes, e.g., an increasing proportion of oxidic impurities. Thus the solutions heretofore proposed have the disadvantage of needing continual readjustment.
The present invention provides a solution which gives a good microcracked deposit of good covering power over areas of varying shape and current density and good uniform color and which maintains these characteristics over a long period with little or no maintenance, using a low proportion of fluoride and an adequate range of sulphate.
Inclusions of boric acid in chromiufn plating baths has been considered undesirable (e.g. page 179 of Electroplating Laboratory Manual" by R.C. Armet publishedby Robert Draper Limited of, Teddington which states that poor rinsing from a bright nickel solution will result in nickel, boric acid, sulphate and chloride entering the chromium bath, all troublesome impurities resulting in lowering of covering power"). Our own experience confirms that boric acid is commonly used in nickel plating baths and this results in some boric acid being carried over with the chromium plating baths with detrimental effects, e.g., boric acid added to certain otherwise reasonably satisfactory electrolyte solutions causes loss of microcracks. As far as we are aware boric acid has never been proposed as an addition to electrolytes for producing microcracked chromium'coating.
The present invention is based on the discovery that the combination of a high content of boric acid or of a salt giving rise to borate ions (B0,), in combination with selenium ions produces a surprising combination of advantages.
The boric acid or a salt giving rise to borate ions may be used in quantity from two grams per liter of electrolyte solution up to a saturated solution.
The incorporation of the boric acid or salt makes the electrolyte more tolerant to variation of the CrO /SO, ratios.
A suitable salt is sodium or potassium perborate or borax.
The electrolyte solution of the present invention gives a good bright color (less blue), is tolerant to a high proportion of oxides, has good throwing and covering power, good cathode efficiency, even distribution of microcracks, and tolerant to fluoride and wide range of sulphate.
For example, in accordance with the present invention, we may provide a solution for use as an electrolyte for electrolytic deposition of chromium comprising an aqueous solution containing chromic acid (CrO boric acid or salt giving borate ions, a fluorine-containing compound, a sulphate-ion-containing compound, and a selenium compound; the selenium compound containing from 0.003 to 0.012, e.g., 0.003 to 0.009 selenium dioxide gram per liter, preferably 0.005 to 0.009; the quantity of CrO being 180 to 250 grams per liter, and the ratio of CrO to fluoride ion is 110 to 320 to 1, preferably 190 to 220 to 1. The ratio of sulphate ion to fluoride ion may be 0.64 to 2.56 to l for best microcracked deposit best covering and throwing power. The ratio CrO to S0, may be to 250, for best microcracked coating.
The boric acid may be used in any proportion up to maximum solubility but we normally prefer 10-30 grams per liter.
The average operating temperature may be to F, preferably l05-115 F. The cathode current density may be -200 amps per square foot. The period of treatment is normally 6 to 10 minutes.
We have found that, in the absence of boric acid or borate salt, more than. .006 g/l selenium dioxide will cause the cracks to become too fine or may be lost al' together.
A plating time of a minimum 7 minutes at 200 amps/sq.ft. will produce microcracked deposits having cracks of some 700-2000 per linear inch. Deposits of less than 0.00002 inch Cr. surprisingly showed a microporous structure of fine pit-like pores and small cracks that failed to join up as those at greater thickness.
This type of structure was also evident at extremely low current density. A Hull Cell panel plated at 8 amps in this electrolyte for 7 minutes showed a deposit having a crack pattern extending for the first 2% inches from the high current density end and a porous pattern extending to 3% inches from the high current density end.
This showed a covering power, i.e., 3% inches of chrome deposit at 8 amps. In a l-lull Cell this could not be obtained from other similar processes, of uniform color and micro-discontinuities over the entire plating range.
Thus articles of complex shape can be plated by this process and even in low current density areas and/or low thicknesses of chromium improved corrosion resistance can be found by virtue ofhaving microcracks.
The invention also provides a combination of additional advantages, viz. wide current density range, wide temperature range, low fluoride concentration, microcracks over the entire plating range at all thicknesses, and ability to operate satisfactorily with fluorinated hydrocarbons in order to suppress chromium fumes and spray.
A particular example of an electrolyte solution in accordance with this invention consists of:
.007 g/l. selenium oxide 225 g/l. chromic acid 1.5 g/l. potassium silico-fluoride 1.7 g/l. sulphuric acid 20 g/l. boric acid Temperature 115 F.
Cathode current density 150-200 A.S.F.
Thickness of deposit .00003 inch.
In general the electrolyte solution of the present invention can be made up as follows:
Chromic acid 175-450 g/liter.
Sulphuric acid 0.7 to 2.0, e.g., 0.7-1.0 g/liter.
Potassium silicofluoride 1.5 to 3 (fluoride ion 0.78
to 1.2), e.g., 1.5-2.5 g/liter (fluoride ion 0.78 to 1.04).
Selenium compound 0.003-0.009 g/liter.
Boric acid 10 to 30, e.g., -20 g/liter.
Other desirable ratios are as follows:
CrO to S0, 85 to 250 preferably 135-185 for best microcracking. CrO to S0, ion plus fluoride ion 45 to 140. Sulphate plus fluoride ion to Se ion is 212 to 1780. Sulphate to selenium ion is 120 to 1000. Fluoride ion to selenium ion is 90 to 320.
The number of microcracks per inch in the final chromium deposit is 750-2500, preferably 1500-2000.
The fluorine compound may be hydrofluoric acid and/or its salts; fluoboric acid and/or its salts; fluozirconate, fluoaluminate, fluotitanate, sodium and/or potassium silicofluoride.
The selenium may be added as selenic acid, or its alkali metal salts, or selenious oxide.
The solution may also include other agents such as surface active agents and foam depressants.
The thickness of the microcracked chromium layer may in practice be from 0.00002 to 0.00004 inch.
We claim:
1. An acidic aqueous solution for electrodeposition of chromium in microcracked condition having at least v 700 microcracks per linear inch comprising (a) chromic acid (CrO (b) at least two grams per liter of solution ofa boron containing compound selected from the group consisting of boric acid and water soluble salts thereof giving rise to borate ions, 50) sul hate ions, (d) a fluorine containing compoun and e) a selenium compound. I
2. A solution as claimed in claim 1, containing at least ten grams of said boron containing compound per liter of solution.
3. A solution as claimed in claim 1 wherein said selenium compound is selenium dioxide present in an amount of at least 0.003 grams/liter solution, the quantity of CrO is 180 to 450 grams per liter and the weight ratio of CrO to fluoride ion is :1 to 266:1.
4. A solution as claimed in claim 3, wherein the ratio of sulphate ion to fluoride ion is 0.64:1 to 2.56:1 and the ratio ofCrO to S0, is 100:1 to 180:1.
5. A solution as claimed in claim 3, wherein the ratio of fluoride ion to sulphate ion is 2.26:1 to 2.56:1 and the ratio of CrO to S0 is 100:1 to 180: 1.
6. A solution as claimed in claim 3, wherein the solution contains 0.005 to 0.009 grams per leter of selenium dioxide in the selenium compound.
7. A solution as claimed in claim 1 wherein the proportions of the ingredients are:
Chromic acid 175-450 g/liter Sulphuric acid 0.7 to 4.5 g/liter Potassium silico-fluoride 1.5 to 3 (fluoride ion 0.78 to 1.2) g/liter.
Selenium compound at least 0.003 g/liter selenium oxide Boric acid at least 10 g/liter.
8. A process of electrodepositing chromium having 700 to 2000 microcracks per linear inch on nickel, cobalt or nickel-cobalt coated metal articles, wherein the articles are treated in an aqueous solution as defined in claim 1 at an average cathode current density of 150 to 200 amps per square foot and a temperature of 100 to F for 6 to 10 minutes.
9. An article having a microcracked chromium coating prepared according to the process of claim 8.
10. A process of preparing article having a microcracked chromium coating having 700 to 2000 microcracks per linear inch which comprises elec trolytically treating as the cathode an article selected from the group consisting of nickel articles, cobalt articles, nickel-cobalt articles and articles coated with nickel, cobalt or nickel-cobalt in an acidic aqueous solution consisting essentially of (a) 180 to 400 g/liter CrO at least 10 g/liter of a boron containing compound selected from the group consisting of boric acid or salts thereof, sulfate ions present in a weight ratio of CrO to S0,, 100:1 to 180:1, a fluorine containing compound selected from the group consisting of hydrofluoric acid, fluorboric acid, salts of fluorboric acid, fluozirconate, fluoaluminate, fluotitanate, sodium silicafluoride and potassium silicafluoride in an amount providing fluoride to CrO in a weight ratio of 1:1 10 to 1:320 and at least 0.006 g/liter, calculated as selenium dioxide, of a selenium compound selected from the group consisting of selenic acid, alkali metal salts thereof and selenious oxide, for about 6 to 10 minutes at 100 to 120 F with an average current density of -200 amp/ft.
I i 1 i i
Claims (9)
1. An acidic aqueous solution for electrodeposition of chromium in microcracked condition having at least 700 microcracks per linear inch comprising (a) chromic acid (CrO3), (b) at least two grams per liter of solution of a boron containing compound selected from the group consisting of boric acid and water soluble salts thereof giving rise to borate ions, (c) sulphate ions, (d) a fluorine containing compound, and (e) a selenium compound.
2. A solution as claimed in claim 1, containing at least ten grams of said boron containing compound per liter of solution.
3. A solution as claimed in claim 1 wherein said selenium compound is selenium dioxide present in an amount of at least 0.003 grams/liter solution, the quantity of CrO3 is 180 to 450 grams per liter and the weight ratio of CrO3 to fluoride ion is 110:1 to 266:1.
4. A solution as claimed in claim 3, wherein the ratio of sulphate ion to fluoride ion is 0.64:1 to 2.56:1 and the ratio of CrO3 to SO4 is 100:1 to 180:1.
5. A solution as claimed in claim 3, wherein the ratio of fluoride ion to sulphate ion is 2.26:1 to 2.56:1 and the ratio of CrO3 to SO4 is 100:1 to 180:1.
6. A solution as claimed in claim 3, wherein the solution contains 0.005 to 0.009 grams per leter of selenium dioxide in the selenium compound.
7. A solutIon as claimed in claim 1 wherein the proportions of the ingredients are: Chromic acid - 175-450 g/liter Sulphuric acid - 0.7 to 4.5 g/liter Potassium silico-fluoride - 1.5 to 3 (fluoride ion 0.78 to 1.2) g/liter. Selenium compound - at least 0.003 g/liter selenium oxide Boric acid - at least 10 g/liter.
8. A process of electrodepositing chromium having 700 to 2000 microcracks per linear inch on nickel, cobalt or nickel-cobalt coated metal articles, wherein the articles are treated in an aqueous solution as defined in claim 1 at an average cathode current density of 150 to 200 amps per square foot and a temperature of 100* to 120* F for 6 to 10 minutes.
9. An article having a microcracked chromium coating prepared according to the process of claim 8.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB4980269 | 1969-10-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3713999A true US3713999A (en) | 1973-01-30 |
Family
ID=10453585
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US00080220A Expired - Lifetime US3713999A (en) | 1969-10-10 | 1970-10-12 | Electrodeposition of chromium |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US3713999A (en) |
| JP (1) | JPS4948621B1 (en) |
| CA (1) | CA937531A (en) |
| FR (1) | FR2064241B1 (en) |
| GB (1) | GB1289117A (en) |
| NL (1) | NL7014782A (en) |
| ZA (1) | ZA706772B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2287532A1 (en) * | 1974-10-07 | 1976-05-07 | Parker Ste Continentale | IMPROVEMENTS RELATING TO THE ELECTROLYTIC DEPOSIT OF MICRO-CRACK CHROME |
| US20040007469A1 (en) * | 2002-05-07 | 2004-01-15 | Memgen Corporation | Selective electrochemical deposition methods using pyrophosphate copper plating baths containing ammonium salts, citrate salts and/or selenium oxide |
| US20060040124A1 (en) * | 2004-01-30 | 2006-02-23 | Kabushiki Kaisha Riken | Composite chromium plating film and sliding member having the same and method for manufacture thereof |
| CN101812706A (en) * | 2009-02-16 | 2010-08-25 | 新日铁住金不锈钢株式会社 | The chromium plating stainless steel plate of processing back corrosion resistance excellent |
| CN103757666B (en) * | 2009-02-16 | 2019-01-15 | 新日铁住金不锈钢株式会社 | The chromium plating stainless steel plate of corrosion resistance excellent after processing |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU4610272A (en) * | 1971-09-07 | 1974-03-07 | M & T Chemicals Inc | Wearing surface |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3069333A (en) * | 1961-07-25 | 1962-12-18 | Du Pont | Chromium plating |
| US3303114A (en) * | 1964-01-10 | 1967-02-07 | Udylite Corp | Chromium plating |
| US3340165A (en) * | 1964-07-20 | 1967-09-05 | M & T Chemicals Inc | Method of electroplating microcrack chromium |
| US3418220A (en) * | 1963-08-26 | 1968-12-24 | Roggendorf Wilhelm | Electrodeposition of chromium and duplex micro-crack chromium coatings |
| US3505183A (en) * | 1964-12-28 | 1970-04-07 | Edgar J Seyb Jr | Process and compositions for electroplating chromium |
| US3514380A (en) * | 1967-02-17 | 1970-05-26 | Kewanee Oil Co | Chromium plating from a fluosilicate type bath containing sodium,ammonium and/or magnesium ions |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1407483A (en) * | 1963-09-11 | 1965-07-30 | Udylite Corp | Improvements to electrolytic chrome baths |
| US3303113A (en) * | 1963-10-18 | 1967-02-07 | Udylite Corp | Chromium plating |
| US3282812A (en) * | 1964-02-20 | 1966-11-01 | Udylite Corp | Electrodeposition of chromium |
-
1969
- 1969-10-10 GB GB4980269A patent/GB1289117A/en not_active Expired
-
1970
- 1970-10-05 ZA ZA706772A patent/ZA706772B/en unknown
- 1970-10-08 NL NL7014782A patent/NL7014782A/xx unknown
- 1970-10-08 CA CA095159A patent/CA937531A/en not_active Expired
- 1970-10-09 JP JP7091947A patent/JPS4948621B1/ja active Pending
- 1970-10-09 FR FR7036599A patent/FR2064241B1/fr not_active Expired
- 1970-10-12 US US00080220A patent/US3713999A/en not_active Expired - Lifetime
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3069333A (en) * | 1961-07-25 | 1962-12-18 | Du Pont | Chromium plating |
| US3418220A (en) * | 1963-08-26 | 1968-12-24 | Roggendorf Wilhelm | Electrodeposition of chromium and duplex micro-crack chromium coatings |
| US3303114A (en) * | 1964-01-10 | 1967-02-07 | Udylite Corp | Chromium plating |
| US3340165A (en) * | 1964-07-20 | 1967-09-05 | M & T Chemicals Inc | Method of electroplating microcrack chromium |
| US3505183A (en) * | 1964-12-28 | 1970-04-07 | Edgar J Seyb Jr | Process and compositions for electroplating chromium |
| US3514380A (en) * | 1967-02-17 | 1970-05-26 | Kewanee Oil Co | Chromium plating from a fluosilicate type bath containing sodium,ammonium and/or magnesium ions |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2287532A1 (en) * | 1974-10-07 | 1976-05-07 | Parker Ste Continentale | IMPROVEMENTS RELATING TO THE ELECTROLYTIC DEPOSIT OF MICRO-CRACK CHROME |
| US20040007469A1 (en) * | 2002-05-07 | 2004-01-15 | Memgen Corporation | Selective electrochemical deposition methods using pyrophosphate copper plating baths containing ammonium salts, citrate salts and/or selenium oxide |
| US20060040124A1 (en) * | 2004-01-30 | 2006-02-23 | Kabushiki Kaisha Riken | Composite chromium plating film and sliding member having the same and method for manufacture thereof |
| US7318963B2 (en) * | 2004-01-30 | 2008-01-15 | Kabushiki Kaisha Riken | Composite chromium plating film and sliding member having the same and method for manufacture thereof |
| CN101812706A (en) * | 2009-02-16 | 2010-08-25 | 新日铁住金不锈钢株式会社 | The chromium plating stainless steel plate of processing back corrosion resistance excellent |
| CN103757666B (en) * | 2009-02-16 | 2019-01-15 | 新日铁住金不锈钢株式会社 | The chromium plating stainless steel plate of corrosion resistance excellent after processing |
Also Published As
| Publication number | Publication date |
|---|---|
| ZA706772B (en) | 1971-07-28 |
| JPS4948621B1 (en) | 1974-12-23 |
| NL7014782A (en) | 1971-04-14 |
| FR2064241A1 (en) | 1971-07-16 |
| FR2064241B1 (en) | 1973-11-23 |
| CA937531A (en) | 1973-11-27 |
| DE2049790A1 (en) | 1971-04-22 |
| DE2049790B2 (en) | 1974-01-03 |
| GB1289117A (en) | 1972-09-13 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AS | Assignment |
Owner name: PERMALITE CHEMICALS LIMITED Free format text: CHANGE OF NAME;ASSIGNOR:MANGRA LIMITED;REEL/FRAME:004260/0899 Effective date: 19840514 Owner name: MANGRA LIMITED, 24 WADSWORTH ROAD, PERIVALE, MIDDL Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:PERMALITE CHEMICALS LIMITED;REEL/FRAME:004260/0894 Effective date: 19840514 |