Patent US3715236A successfully refreshed from Google Patents.
US3715236A
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Descaling method for steel
Assignee: Mitsubishi Heavy Industries Ltd
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Filing: 1970-10-08
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Granted: 1973-02-06
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Expires: 1990-10-08
Abstract
Abstract Chromium-containing steel is descaled by wetting the surface of the steel after annealing and while still hot with a mixed aqueous solution of caustic soda and/or caustic potash containing at least one alkali metal salt capable of forming caustic soda or caustic potash by hydrolysis or with an aqueous solution of two or more alkali metal salts which are capable of forming caustic soda or caustic potash by hydrolysis. The water of the solution is evaporated by the retained heat of the steel and the mixture of alkali metal salts is retained on the surface of the steel in an oxygen-containing atmosphere for a period sufficient to convert the scale components into water- or acid-soluble materials.
Inventors
- 👤 S Fukui
- 👤 M Miyake
- 👤 M Okumoto
- 👤 T Yamazaki
- 👤 M Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:12
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/14; C23G1/19
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
8 words
A method of descaling chromium-containing steel, which comprises
Claim 2
Independent Claim
8 words
A method of descaling chromium-containing steel, which comprises
Claim 3
Dependent Claim
58 words
wetting the surface of the steel after annealing and while still in the hot state with an aqueous solution containing (i) a member selected from the group consisting of caustic soda, caustic potash, and mixtures thereof, and (ii) at least one member selected from the group consisting of alkali metal carbonate, alkali metal sulfate, and alkali metal silicate,
Claim 4
Dependent Claim
58 words
wetting the surface of the steel after annealing and while still in the hot state with an aqueous solution containing (i) a member selected from the group consisting of caustic soda, caustic potash, and mixtures thereof, and (ii) at least one member selected from the group consisting of alkali metal carbonate, alkali metal sulfate, and alkali metal silicate,
Claim 5
Dependent Claim
46 words
wetting the surface of the steel after annealing and while still in the hot state with an aqueous solution containing at least two members selected from the group consisting of alkali metal carbonate, alkali metal sulfate, alkali metal silicate, alkali metal nitrate, and alkali metal chlorate,
Claim 6
Dependent Claim
46 words
wetting the surface of the steel after annealing and while still in the hot state with an aqueous solution containing at least two members selected from the group consisting of alkali metal carbonate, alkali metal sulfate, alkali metal silicate, alkali metal nitrate, and alkali metal chlorate,
Claim 7
Dependent Claim
14 words
evaporating the water of the solution by the retained heat of the steel, and
Claim 8
Dependent Claim
14 words
evaporating the water of the solution by the retained heat of the steel, and
Claim 9
Dependent Claim
22 words
A method as claimed in claim 1, wherein the solution consists of aqueous alkali metal carbonate, alkali metal sulfate and caustic soda.
Claim 10
Dependent Claim
14 words
evaporating the water of the solution by the retained heat of the steel, and
Claim 11
Dependent Claim
14 words
evaporating the water of the solution by the retained heat of the steel, and
Claim 12
Dependent Claim
69 words
retaining the mixture of alkali metal salts, molten at 250* -950* C., on the surface of the steel in an oxygen-containing atmosphere for a period of time sufficient to convert the scale components into water-or acid-soluble materials, the concentration of said solution being from about 5 to about 50 percent by weight and the concentration of the caustic alkali not exceeding about 2.5 percent by weight of the solution.
Claim 13
Dependent Claim
69 words
retaining the mixture of alkali metal salts, molten at 250* -950* C., on the surface of the steel in an oxygen-containing atmosphere for a period of time sufficient to convert the scale components into water-or acid-soluble materials, the concentration of said solution being from about 5 to about 50 percent by weight and the concentration of the caustic alkali not exceeding about 2.5 percent by weight of the solution.
Claim 14
Dependent Claim
71 words
retaining the mixture of alkali metal salts, molten at 250* -950* C., on the surface of the steel in an oxygen-containing atmosphere for a period of time sufficient to convert the scale components into water-or acid-soluble materials, the concentration of said solution being from about 5 to about 50 percent by weight and the concentration of the caustic alkali component (i) not exceeding about 2.5 percent by weight of the solution.
Claim 15
Dependent Claim
71 words
retaining the mixture of alkali metal salts, molten at 250* -950* C., on the surface of the steel in an oxygen-containing atmosphere for a period of time sufficient to convert the scale components into water-or acid-soluble materials, the concentration of said solution being from about 5 to about 50 percent by weight and the concentration of the caustic alkali component (i) not exceeding about 2.5 percent by weight of the solution.
Claim 16
Dependent Claim
23 words
A method as claimed in claim 1, wherein said alkali metal is selected from the group consisting of (i) sodium, and (ii) potassium.
Claim 17
Dependent Claim
24 words
A method as claimed in claim 1, wherein the concentration of the caustic alkali component (i) does not exceed about 1.25 percent by weight.
Claim 18
Dependent Claim
20 words
A method as claimed in claim 1, wherein the solution consists of aqueous sodium carbonate, sodium sulfate and caustic soda.
Claim 19
Dependent Claim
32 words
A method as claimed in claim 5, wherein the solution consists of 5 percent sodium carbonate, 5 percent sodium sulfate and 0.5 percent caustic soda, all of said percents being by weight.
Claim 20
Independent Claim
8 words
A method of descaling chromium-containing steel, which comprises
Claim 21
Independent Claim
8 words
A method of descaling chromium-containing steel, which comprises
Claim 22
Dependent Claim
21 words
A method as claimed in claim 7, wherein the solution consists of alkali metal carbonate, alkali metal nitrate and caustic soda.
Claim 23
Dependent Claim
23 words
A method as claimed in claim 7, wherein said alkali metal is selected from the group consisting of (i) sodium, and (ii) potassium.
Claim 24
Dependent Claim
20 words
A method as claimed in claim 7, wherein the solution consists of aqueous potassium carbonate, sodium nitrate, and caustic soda.
Claim 25
Dependent Claim
33 words
A method as claimed in claim 10, wherein the solution consists of about 5 percent potassium carbonate, 5 percent sodium nitrate, and 0.5 percent caustic soda, all of said percents being by weight.
Claim 26
Dependent Claim
19 words
A method according to claim 7, wherein the solution consists of aqueous alkali metal silicate and alkali metal nitrate.
Claim 27
Dependent Claim
17 words
A method according to claim 12, wherein the solution consists of aqueous sodium silicate and sodium nitrate.
Claim 28
Dependent Claim
29 words
A method according to claim 13, wherein the solution consists of about 50 percent sodium silicate and about 3 percent sodium nitrate, all of said percents being by weight.
Claim 29
Dependent Claim
19 words
A method according to claim 7, wherein the solution consists of aqueous alkali metal carbonate and alkali metal chlorate.
Claim 30
Dependent Claim
16 words
A method according to claim 15, wherein the solution consists of sodium carbonate and sodium chlorate.
Claim 31
Dependent Claim
28 words
A method according to claim 16, wherein the solution consists of about 5 percent sodium carbonate and 1 percent sodium chlorate, all of said percents being by weight.
Claim 32
Dependent Claim
20 words
A method as claimed in claim 7, wherein the solution consists of aqueous sodium carbonate, sodium nitrate and caustic soda.
Claim 33
Dependent Claim
35 words
A method as claimed in claim 18, wherein the solution consists of about 10 percent sodium carbonate, about 3 percent sodium nitrate, and about 1 percent caustic soda, all of said percents being by weight.
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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) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |