Patent US4643979A successfully refreshed from Google Patents.
US4643979A
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Method for detecting phosphorus segregates in steel
Assignee: JFE Steel Corp
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Filing: 1984-11-13
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Granted: 1987-02-17
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Expires: 2004-11-13
Abstract
Abstract Phosphorus segregates formed in cast steel upon solidifying are detected by a novel method comprising applying a metal etching reagent, for example, lithium chloride in ethanol, to a surface area of the steel to be examined, and attaching a sheet of test paper bearing an aqueous solution of silver nitrate to said surface, thereby detecting phosphorus segregates as stains on the sheet.
Inventors
- 👤 Yoshiko Funahashi
- 👤 Yasuharu Matsumura
- 👤 Senichi Harimaya
- 👤 Yoshikazu Kamino
- 👤 Hidenari Kitaoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:31
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; G01N31/221; G01N33/00; G01N33/20; G01N33/202; G01N33/2022; Y; Y10; Y10T; Y10T436/00; Y10T436/16; Y10T436/25; Y10T436/25125
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
65 words
A method for detecting phosphorus segregates in solidified steel, comprising the steps of applying a metal etching reagent to a surface area of the solidified steel to be examined, said metal etching reagent causing the eventual formation of phosphine, and applying a test sheet bearing a solution of a heavy metal salt against said surface area, thereby detecting phosphorus segregates as stains on the sheet.
Claim 2
Independent Claim
65 words
A method for detecting phosphorus segregates in solidified steel, comprising the steps of applying a metal etching reagent to a surface area of the solidified steel to be examined, said metal etching reagent causing the eventual formation of phosphine, and applying a test sheet bearing a solution of a heavy metal salt against said surface area, thereby detecting phosphorus segregates as stains on the sheet.
Claim 3
Dependent Claim
23 words
The method according to claim 1 wherein the metal etching reagent is a solution of an acid or salt thereof in an alcohol.
Claim 4
Dependent Claim
25 words
The method according to claim 2 wherein the acid or salt is selected from the group consisting of mineral acids, organic acids, and salts thereof.
Claim 5
Dependent Claim
13 words
The method according to claim 3 wherein the etching reagent is lithium chloride.
Claim 6
Dependent Claim
20 words
The method according to claim 2 wherein the alcohol is selected from the group consisting of methanol, ethanol, and propanol.
Claim 7
Dependent Claim
30 words
The method according to claim 1 wherein the heavy metal salt is selected from silver nitrate, silver bromide, silver iodide, gold chloride, and copper chloride, and is dissolved in water.
Claim 8
Dependent Claim
25 words
The method according to claim 1 wherein the heavy metal salt solution contains 0.1 to 80% by weight of the heavy metal salt in water.
Claim 9
Dependent Claim
25 words
The method according to claim 1 wherein the heavy metal salt solution is an aqueous solution containing 0.1 to 80% by weight of silver nitrate.
Claim 10
Dependent Claim
12 words
The method according to claim 1 wherein the test sheet is paper.
Claim 11
Dependent Claim
25 words
The method according to claim 1 wherein the test sheet is pressed against the steel surface for a sufficient time to provide a printed image.
Claim 12
Dependent Claim
34 words
The method according to claim 10 which further comprises immersing the test sheet, after removal from the steel surface, in a solution of sodium thiosulfate for a sufficient time to fix the printed image.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1990-02-16 | 1990-08-18 | 1991-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-16 | 1994-08-18 | 1995-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-16 | 1998-08-18 | 1999-02-17 | $7700.00 | Window Closed / Lapsed |