US4204884A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of conditioning cast steel for hot working
Assignee: Ingersoll Steel Co
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Filing: 1979-03-15
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Granted: 1980-05-27
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Expires: 1999-03-15
Abstract
Abstract Cast bodies of steel grades which do not undergo phase transformation upon heating for hot working, for example, the austenitic stainless steels, are conditioned to undergo recrystallization upon subsequent heating by cold working the body as the first step in making it into an intermediate product, such as a slab, plate, band or billet. Upon subsequent heating, the steel recrystallizes to a finer grain structure with substantially altered grain boundaries. Such recrystallization substantially reduces the incidence of surface defects and edge cracking during subsequent hot working.
Inventors
- 👤 Erik E. Berg
- 👤 Rolf Tingwall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:12
CPC Classifications
C; C21; C21D; C21D7/00; C21D7/02; C21D8/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
103 words
A method of conditioning a cast steel body to undergo recrystallization upon heating to reduce the tendency for surface defects and edge-cracking upon hot working, the steel being of a grade which does not exhibit phase transformation when heated for hot working, comprising the step of cold rolling the body to an extent such that the cross-section quotient product after cold rolling is from about 0.99 to about 0.75; such step being performed on the body as the first step in converting it to an intermediate slab, plate, band or billet without prior treatment other than initial removal of scale and surface defects.
Claim 2
Independent Claim
103 words
A method of conditioning a cast steel body to undergo recrystallization upon heating to reduce the tendency for surface defects and edge-cracking upon hot working, the steel being of a grade which does not exhibit phase transformation when heated for hot working, comprising the step of cold rolling the body to an extent such that the cross-section quotient product after cold rolling is from about 0.99 to about 0.75; such step being performed on the body as the first step in converting it to an intermediate slab, plate, band or billet without prior treatment other than initial removal of scale and surface defects.
Claim 3
Dependent Claim
16 words
A method according to claim 1 wherein the cast body has a substantially uniform cross section.
Claim 4
Dependent Claim
20 words
A method according to claim 1 or 2 wherein the cross-section quotient product is from about 0.975 to about 0.90.
Claim 5
Dependent Claim
22 words
A method according to claim 1 wherein the body is cold rolled by at least one pass through a hot rolling mill.
Claim 6
Dependent Claim
25 words
A method according to claim 4 wherein the hot rolling mill is the same one as the body is later to be hot rolled in.
Claim 7
Dependent Claim
17 words
A method according to claim 1 wherein the steel of the body is an austenitic stainless steel.
Claim 8
Independent Claim
92 words
A method of conditioning a cast body of austenitic stainless steel to undergo recrystallization upon subsequent heating to reduce the tendency for surface defects and edge-cracking upon hot working, consisting of the step of cold rolling the body by at least one pass through a rolling mill such that the cross-section quotient product is from about 0.975 to about 0.90, such step being performed as the first step in reducing the body to an intermediate slab, plate, band or billet without prior treatment other than initial removal of scale and surface defects.
Claim 9
Independent Claim
92 words
A method of conditioning a cast body of austenitic stainless steel to undergo recrystallization upon subsequent heating to reduce the tendency for surface defects and edge-cracking upon hot working, consisting of the step of cold rolling the body by at least one pass through a rolling mill such that the cross-section quotient product is from about 0.975 to about 0.90, such step being performed as the first step in reducing the body to an intermediate slab, plate, band or billet without prior treatment other than initial removal of scale and surface defects.
Claim 10
Independent Claim
106 words
A method of conditioning a cast steel body to reduce the tendency for surface defects and edge-cracking upon hot working, the steel being of a grade which does not exhibit phase transformation when heated for hot working, consisting of the step of cold rolling the body to cause recrystallization upon heating to a substantially finer and stronger grain structure with substantially altered grain boundaries, as compared to the grain structure in the body as cast, such step being carried out as the first step in reducing the body to a slab, plate, band or billet without prior treatment other than removal of scale and surface defects.
Claim 11
Independent Claim
106 words
A method of conditioning a cast steel body to reduce the tendency for surface defects and edge-cracking upon hot working, the steel being of a grade which does not exhibit phase transformation when heated for hot working, consisting of the step of cold rolling the body to cause recrystallization upon heating to a substantially finer and stronger grain structure with substantially altered grain boundaries, as compared to the grain structure in the body as cast, such step being carried out as the first step in reducing the body to a slab, plate, band or billet without prior treatment other than removal of scale and surface defects.
Claim 12
Dependent Claim
70 words
In a method of processing a cast body of a steel that does not exhibit phase transformation upon heating for hot working, the step of cold rolling the cast steel body such that the cross-section quotient product is from about 0.99 to about 0.75 to condition the body to undergo recrystallization during heating prior to subsequent hot working, thereby reducing the tendency for surface defects and edge-cracking upon hot working.
Claim 13
Dependent Claim
70 words
In a method of processing a cast body of a steel that does not exhibit phase transformation upon heating for hot working, the step of cold rolling the cast steel body such that the cross-section quotient product is from about 0.99 to about 0.75 to condition the body to undergo recrystallization during heating prior to subsequent hot working, thereby reducing the tendency for surface defects and edge-cracking upon hot working.
References Cited (Backward Citations)
US2931744A
Cited
US3347715A
Cited
US3285789A
Cited
US3340048A
Cited
US3678571A
Cited
US4086105A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-05-27 | 1983-11-26 | 1984-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-05-27 | 1987-11-26 | 1988-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-05-27 | 1991-11-26 | 1992-05-27 | $7700.00 | Window Closed / Lapsed |