US3948649A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Free cutting steel
Assignee: Daido Steel Co Ltd
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Filing: 1974-03-01
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Granted: 1976-04-06
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Expires: 1994-03-01
Abstract
Abstract A free cutting steel for construction of machines, characterized in that the deoxidation product remaining in the steel has a composition of 40-60% of SiO 2 , 10-30% of MnO and 5-25% of Al 2 O 3 , the balance being other oxides such as CaO and the sum of contents of SiO 2 , MnO and Al 2 O 3 being so adjusted as to be at least 85% of the whole oxides in the deoxidation products, the steel being further incorporated with 0.02 - 0.10% of Pb, and that the non-metallic composite inclusions comprising sulfides and finely divided Pb particles are uniformly dispersed.
Inventors
- 👤 Tetsuo Takahashi
- 👤 Minoru Yanagida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:36
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/60
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
194 words
A free cutting steel for machine structural use having an excellent machinability for cutting with a high speed steel cutting tool, which consisting essentially of carbon 0.08 to 0.65%, silicon 0.10 to 0.35%, manganese 0.30 to 1.90%, nickel 0 to 4.50%, chromium 0 to 3.50%, molybdenum 0 to 0.70%, lead 0.02 to 0.10%, and the balance iron and inherent impurities, and further contains oxide inclusion within a range from 100 to 450 grams per ton of the steel, lead within the range of 0.02 to 0.10 percent by weight of the said oxide inclusion being uniformly dispersed composite inclusion consisting essentially of SiO 2 40 to 60% by weight, MnO 10 to 30%, Al 2 O 3 5 to 25% and MO up to 15%, wherein MO is an oxide of a metal selected from the group consisting of calcium, magnesium and iron, and the sum of SiO 2 , MnO and Al 2 O 3 amounts to at least 85% of the oxide inclusion, and substantially all of the lead being uniformly distributed in the steel as finely divided particles in the form of composite inclusions comprising sulfides and finely divided lead particles.
Claim 2
Dependent Claim
194 words
A free cutting steel for machine structural use having an excellent machinability for cutting with a high speed steel cutting tool, which consisting essentially of carbon 0.08 to 0.65%, silicon 0.10 to 0.35%, manganese 0.30 to 1.90%, nickel 0 to 4.50%, chromium 0 to 3.50%, molybdenum 0 to 0.70%, lead 0.02 to 0.10%, and the balance iron and inherent impurities, and further contains oxide inclusion within a range from 100 to 450 grams per ton of the steel, lead within the range of 0.02 to 0.10 percent by weight of the said oxide inclusion being uniformly dispersed composite inclusion consisting essentially of SiO 2 40 to 60% by weight, MnO 10 to 30%, Al 2 O 3 5 to 25% and MO up to 15%, wherein MO is an oxide of a metal selected from the group consisting of calcium, magnesium and iron, and the sum of SiO 2 , MnO and Al 2 O 3 amounts to at least 85% of the oxide inclusion, and substantially all of the lead being uniformly distributed in the steel as finely divided particles in the form of composite inclusions comprising sulfides and finely divided lead particles.
Claim 3
Dependent Claim
45 words
A free cutting steel according to claim 1, wherein said steel for machine structural use is a plain carbon steel consisting of 0.08 to 0.60% of carbon, 0.10 to 0.30% of silicon, 0.30 to 1.65% of manganese and the remainder essentially iron and inherent impurities.
Claim 4
Dependent Claim
41 words
A free cutting steel according to claim 1, wherein the steel for machine structural use is a plain carbon steel comprising 0.08 to 0.61% carbon, 0.15 to 0.35% silicon, 0.30 to 0.90% manganese and the remainder essentially iron and inherent impurities.
Claim 5
Dependent Claim
41 words
A free cutting steel according to claim 1, wherein the steel for machine structural use is a plain carbon steel comprising 0.40 to 0.55% carbon, 0.15 to 0.35% silicon, 0.60 to 1.00% manganese and the remainder essentially iron and inherent impurities.
Claim 6
Dependent Claim
44 words
A free cutting steel according to claim 1, wherein the steel for machine structural uses is a chromium steel comprising 0.12 to 0.64% carbon, 0.20 to 0.35% silicon, 0.30 to 1.00% manganese, 0.30 to 1.15% chromium and the remainder essentially iron and inherent impurities.
Claim 7
Dependent Claim
44 words
A free cutting steel according to claim 1, wherein the steel for machine structural use is a chromium steel comprising 0.13 to 0.48% carbon, 0.15 to 0.35% silicon, 0.60 to 0.85% manganese, 0.90 to 1.20% chromium and the remainder essentially iron and inherent impurities.
Claim 8
Dependent Claim
48 words
A free cutting steel according to claim 1, wherein the steel for machine structural use is a chromium-molybdenum steel comprising 0.18 to 0.65% carbon, 0.15 to 0.35% silicon, 0.30 to 1.00% manganese, 0.70 to 1.20% chromium, 0.08 to 0.35% molybdenum and the remainder essentially iron and inherent impurities.
Claim 9
Dependent Claim
40 words
A free cutting steel according to claim 1, wherein the steel for machine structural use is a manganese steel comprising 0.17 to 0.48% carbon, 0.15 to 0.35% silicon, 1.20 to 1.90% manganese and the remainder essentially iron and inherent impurities.
Claim 10
Dependent Claim
44 words
A free cutting steel according to claim 1, wherein the steel for machine structural use is a molybdenum steel comprising 0.09 to 0.50% carbon, 0.20 to 0.35% silicon, 0.65 to 1.00% manganese, 0.15 to 0.60% molybdenum and the remainder essentially iron and inherent impurities.
Claim 11
Dependent Claim
44 words
A free cutting steel according to claim 1, wherein the steel for machine structural use is a manganese-chromium steel comprising 0.17 to 0.46% carbon, 0.15 to 0.35% silicon, 1.20 to 1.65% manganese, 0.35 to 0.70% chromium and the remainder essentially iron and inherent impurities.
Claim 12
Dependent Claim
48 words
A free cutting steel according to claim 1, wherein the steel for machine structural use is a chromium-molybdenun steel comprising 0.18 to 0.23% carbon, 0.15 to 0.35% silicon, 0.60 to 0.85% manganese, 0.90 to 1.20% chromium, 0.15 to 0.30% molybdenum and the remainder essentially iron and inherent impurities.
Claim 13
Dependent Claim
48 words
A free cutting steel according to claim 1, wherein the steel for machine structural use is a nickel-chromium steel comprising 0.12 to 0.40% carbon, 0.15 to 0.35% silicon, 0.35 to 0.80% manganese, 1.00 to 3.50% nickel, 0.20 to 1.00% chromium and the remainder essentially iron and inherent impurities.
Claim 14
Dependent Claim
52 words
A free cutting steel according to claim 1, wherein the steel for machine structural use is a nickel-chromium-molybdenum steel comprising 0.08 to 0.64% carbon, 0.20 to 0.35% silicon, 0.45 to 1.00% manganese, 0.40 to 3.50% nickel, 0.30 to 1.40% chromium, 0.08 to 0.40% molybdenum and the remainder essentially iron and inherent impurities.
Claim 15
Dependent Claim
52 words
A free cutting steel according to claim 1, wherein the steel for machine structural use is a nickel-chromium-molybdenum steel comprising 0.12 to 0.50% carbon, 0.15 to 0.35% silicon, 0.35 to 1.20% manganese, 0.40 to 4.50% nickel, 0.40 to 3.50% chromium, 0.15 to 0.70% molybdenum and the remainder essentially iron and inherent impurities.
References Cited (Backward Citations)
US2236479A
Cited
US2914400A
Cited
US3203788A
Cited
US3630723A
Cited
US3634074A
Cited
US3729293A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-06 | 1979-10-06 | 1980-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-06 | 1983-10-06 | 1984-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-06 | 1987-10-06 | 1988-04-06 | $7700.00 | Window Closed / Lapsed |