US4718992A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Test medium and method for detecting phosphorus segregates in metallic material
Assignee: JFE Steel Corp
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Filing: 1986-08-19
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Granted: 1988-01-12
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Expires: 2006-08-19
Abstract
Abstract An aqueous electrolytic solution of a molybdate ion and an oxidizing agent is effective to detect phosphorus segregates in a metallic material, particularly cast steel through electrolysis. Segregated phosphorus can be detected by (a) applying a test sheet against a surface area of the metallic material to be examined for segregation, (b) introducing an aqueous electrolytic solution comprising 0.1 to 20% by weight of a molybdate ion and an oxidizing agent between the metallic material surface area and the sheet, (c) contacting a cathode plate with the sheet, (d) effecting electrolysis with the metallic material made anode, (e) removing the sheet from the metallic material surface, and (f) treating the sheet with a reducing agent.
Inventors
- 👤 Yoshiko Funahashi
- 👤 Yoshikazu Kamino
- 👤 Yasuharu Matsumura
- 👤 Senichi Harimaya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:00
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/42; G01N30/00; G01N33/00; G01N33/20; G01N33/202; G01N33/2022; Y; Y10; Y10T; Y10T436/00; Y10T436/16
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
102 words
A method for detecting phosphorus segregates in a metallic material, comprising the steps of: (a) applying a test sheet against a surface area of the metallic material to be examined for segregation, (b) introducing an aqueous electrolytic solution comprising 0.1 to 20% by weight of a molybdate ion and an oxidizing agent between at least the metallic material surface area and the sheet, (c) contacting a cathode plate with said sheet, (d) effecting electrolysis with said metallic material made anode, (e) removing the sheet from the metallic material surface area, and (f) treating the sheet with a reagent comprising a reducing agent.
Claim 2
Independent Claim
102 words
A method for detecting phosphorus segregates in a metallic material, comprising the steps of: (a) applying a test sheet against a surface area of the metallic material to be examined for segregation, (b) introducing an aqueous electrolytic solution comprising 0.1 to 20% by weight of a molybdate ion and an oxidizing agent between at least the metallic material surface area and the sheet, (c) contacting a cathode plate with said sheet, (d) effecting electrolysis with said metallic material made anode, (e) removing the sheet from the metallic material surface area, and (f) treating the sheet with a reagent comprising a reducing agent.
Claim 3
Dependent Claim
32 words
A method according to claim 1 wherein the electrolysis is carried out by an electrolysis-at-constant-current process at a current density of 1 to 10 mA/cm 2 for about 2 to 20 minutes.
Claim 4
Dependent Claim
20 words
A method according to claim 1 wherein the electrolytic solution contains 0.5 to 7N nitric acid as the oxidizing agent.
Claim 5
Dependent Claim
34 words
A method according to claim 1 wherein the electrolytic solution contains at least one member selected from the group consisting of ammonium molybdate, sodium molybdate, lithium molybdate, magnesium molybdate, calcium molybdate, and potassium molybdate.
Claim 6
Dependent Claim
25 words
A method according to claim 1 wherein the reducing agent is selected from the group consisting of stannous chloride, hydroquinone, hydrazine sulfate, and ascorbic acid.
Claim 7
Dependent Claim
32 words
A method according to claim 5 wherein the reagent comprising a reducing agent is a solution containing 0.1 to 20% by weight of stannous chloride and 0.5 to 6N of hydrochloric acid.
Claim 8
Dependent Claim
36 words
A method according to claim 1 wherein the test sheet is impregnated with an aqueous solution containing 0.1 to 20% by weight of a molybdate ion and an oxidizing agent to combine steps (a) and (b).
Claim 9
Independent Claim
133 words
A method for detecting phosphorus segregates in a metallic material, comprising the steps of: (a) maintaining a solution of an oxidizing agent in contact with a surface area of the metallic material to be examined for segregation for a time sufficient to produce on said surface area a stable passive oxide layer, (b) applying a test sheet against the metallic material surface area, (c) introducing an aqueous electrolytic solution comprising 0.1 to 20% by weight of a molybdate ion and an oxidizing agent between at least the metallic material surface area and the sheet, (d) contacting a cathode plate with said sheet, (e) effecting electrolysis with said metallic material made anode, (f) removing the sheet from the metallic material surface area, and (g) treating the sheet with a reagent comprising a reducing agent.
Claim 10
Independent Claim
133 words
A method for detecting phosphorus segregates in a metallic material, comprising the steps of: (a) maintaining a solution of an oxidizing agent in contact with a surface area of the metallic material to be examined for segregation for a time sufficient to produce on said surface area a stable passive oxide layer, (b) applying a test sheet against the metallic material surface area, (c) introducing an aqueous electrolytic solution comprising 0.1 to 20% by weight of a molybdate ion and an oxidizing agent between at least the metallic material surface area and the sheet, (d) contacting a cathode plate with said sheet, (e) effecting electrolysis with said metallic material made anode, (f) removing the sheet from the metallic material surface area, and (g) treating the sheet with a reagent comprising a reducing agent.
Claim 11
Dependent Claim
35 words
A method according to claim 8 wherein the oxidizing solution is selected from the group consisting of solutions of nitric acid, chromic acid, and hydrogen peroxide, and solution containing Ce 4+ and Fe 3+ .
Claim 12
Dependent Claim
32 words
A method according to claim 8 wherein the electrolysis is carried out by an electrolysis-at-constant-current process at a current density of 1 to 10 mA/cm 2 for about 2 to 20 minutes.
Claim 13
Dependent Claim
20 words
A method according to claim 8 wherein the electrolytic solution contains 0.5 to 7N nitric acid as the oxidizing agent.
Claim 14
Dependent Claim
34 words
A method according to claim 8 wherein the electrolytic solution contains at least one member selected from the group consisting of ammonium molybdate, sodium molybdate, lithium molybdate, magnesium molybdate, calcium molybdate, and potassium molybdate.
Claim 15
Dependent Claim
25 words
A method according to claim 8 wherein the reducing agent is selected from the group consisting of stannous chloride, hydroquinone, hydrazine sulfate, and ascorbic acid.
Claim 16
Dependent Claim
32 words
A method according to claim 13 wherein the reagent comprising a reducing agent is a solution containing 0.1 to 20% by weight of stannous chloride and 0.5 to 6N of hydrochloric acid.
Claim 17
Dependent Claim
36 words
A method according to claim 8 wherein the test sheet is impregnated with an aqueous solution containing 0.1 to 20% by weight of a molybdate ion and an oxidizing agent to combine steps (b) and (c).
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-11 | 1991-07-13 | 1992-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-11 | 1995-07-13 | 1996-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-11 | 1999-07-13 | 2000-01-12 | $7700.00 | Window Closed / Lapsed |