US4082577A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the heat treatment of steel
Assignee: Fried Krupp Huettenwerke AG
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Filing: 1975-08-14
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Granted: 1978-04-04
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Expires: 1995-08-14
Abstract
Abstract A process for the heat treatment of a steel rail which is at a temperature which is in the austenite range which comprises quenching at least the head portion of said rail in water maintained at a temperature of at least 80° C until the temperature of said rail is such that said rail has completed the pearlite transformation and recovering a rail whose steel composition is characterized by such a fine pearlitic structure that it cannot be resolved by a light microscope but is not bainitic in structure.
Inventors
- 👤 Wilhelm Heller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:57
CPC Classifications
C; C21; C21D; C21D1/00; C21D1/56; C21D1/60; C21D9/00; C21D9/04; C21D1/62; C21D1/63; Y; Y10; Y10S; Y10S148/00; Y10S148/902
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
83 words
A process for the heat treatment of a steel rail which is at a temperature which is in the austenite range, which process consists essentially of quenching at least the head portion of said rail in boiling water, maintaining the rail in said water until it reaches a temperature of 100° C and recovering a rail whose steel composition is characterized by such a very fine pearlitic structure that it cannot be resolved by a light microscope but is not bainitic in structure.
Claim 2
Dependent Claim
83 words
A process for the heat treatment of a steel rail which is at a temperature which is in the austenite range, which process consists essentially of quenching at least the head portion of said rail in boiling water, maintaining the rail in said water until it reaches a temperature of 100° C and recovering a rail whose steel composition is characterized by such a very fine pearlitic structure that it cannot be resolved by a light microscope but is not bainitic in structure.
Claim 3
Dependent Claim
19 words
A process according to claim 1 wherein the rail is quenched at a temperature of 800° to 850° C.
Claim 4
Dependent Claim
14 words
A process according to claim 1 wherein quenching is carried out from rolling heat.
Claim 5
Dependent Claim
29 words
A process according to claim 1 wherein the rail contains manganese whose quantity is limited so that the production of martensite fractions at the rail base edge is obviated.
Claim 6
Dependent Claim
30 words
A process according to claim 1 wherein the steel comprises 0.4 to 0.60% carbon, up to 0.35% silicon, 0.80 to 1.20% manganese, the remainder being iron with the usual impurities.
Claim 7
Dependent Claim
34 words
A process according to claim 1 wherein the rail steel has a composition comprising 0.60 to 0.75% carbon, up to 0.5% silicon, 0.80 to 1.30% manganese, the remainder being iron with the usual impurities.
Claim 8
Dependent Claim
34 words
A process according to claim 1 wherein the rail steel has a composition comprising 0.50 to 0.70% carbon, up to 0.5% silicon, 1.30 to 1.70% manganese, the balance being iron with the usual impurities.
Claim 9
Dependent Claim
37 words
A process according to claim 1 wherein the steel has a composition comprising 0.65 to 0.80% carbon, 0.60 to 0.90% silicon, 0.80 to 1.30% manganese, 0.80 to 1.30% chromium, the balance being iron with the usual impurities.
Claim 10
Dependent Claim
34 words
A process according to claim 1 wherein the rail steel has a composition comprising 0.40 to 0.90% carbon, up to 1.30% silicon, 0.60 to 1.40% manganese, the balance being iron with the usual impurities.
Claim 11
Dependent Claim
34 words
A process according to claim 1 wherein the rail steel has a composition comprising 0.75 to 0.85% carbon, up to 0.50% silicon, 0.90 to 1.10% manganese, the balance being iron with the usual impurities.
Claim 12
Dependent Claim
34 words
A process according to claim 1 wherein the rail steel has a composition comprising 0.45 to 0.55% carbon, up to 0.50% silicon, 0.70 to 0.90% manganese, the balance being iron with the usual impurities.
Claim 13
Dependent Claim
34 words
A process according to claim 1 wherein the rail steel has a composition comprising 0.40 to 0.50% carbon, up to 0.30% silicon, 0.60 to 0.80% manganese, the balance being iron with the usual impurities.
Claim 14
Dependent Claim
16 words
A process according to claim 1 wherein the steel composition is free of any alloying elements.
Claim 15
Dependent Claim
26 words
A process according to claim 1 wherein after said steel rail has been cooled to a very fine pearlitic structure it is thereafter cooled in air.
Claim 16
Dependent Claim
25 words
A process according to claim 1 wherein the rail is introduced into the bath of boiling water until the rail has completed the pearlitic transformation.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-03 | 1981-10-03 | 1982-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-03 | 1985-10-03 | 1986-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-03 | 1989-10-03 | 1990-04-04 | $7700.00 | Window Closed / Lapsed |