US4115111A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Free-cutting structural steel for machines
Assignee: Daido Steel Co Ltd
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Filing: 1977-01-24
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Granted: 1978-09-19
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Expires: 1997-01-24
Abstract
Abstract The present invention relates to a free-cutting structural steel for machines characterized by containing a range of 30-100 g/steel ton of oxide inclusions mainly composed of SiO2 40-60%, CaO 13-30% and Al2O3 25-40%, the balance being less than 20% of other oxides and calcium 0.0002-0.0010%, and at least one of the following elements; lead 0.03-0.30% and sulfur 0.035-0.10%.
Inventors
- 👤 Tetsuro Itoh
- 👤 Tetsuo Takahashi
- 👤 Atsuyoshi Kimura
- 👤 Seiichi Yamano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:15
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/60
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
87 words
Free-cutting structural steel consisting essentially of 0.05-0.65% carbon, 0.10-0.40% silicon, 0.25-1.70% manganese, 0-4.50% nickel, 0-3.50% chromium, 0-1.0% molybdenum, 0.0002-0.0010% calcium and at least one element selected from the group consisting of 0.03-0.30% lead and 0.04-0.10% sulfur by weight, the balance being iron and impurities, together with 30-100 grams of oxide inclusions per ton of steel, said inclusions comprising 40-60% SiO 2 , 5-30% CaO and 25-40% Al 2 O 3 , with less than 20% of other oxides, said inclusions having a melting point of 1,200°-1,600° C.
Claim 2
Dependent Claim
87 words
Free-cutting structural steel consisting essentially of 0.05-0.65% carbon, 0.10-0.40% silicon, 0.25-1.70% manganese, 0-4.50% nickel, 0-3.50% chromium, 0-1.0% molybdenum, 0.0002-0.0010% calcium and at least one element selected from the group consisting of 0.03-0.30% lead and 0.04-0.10% sulfur by weight, the balance being iron and impurities, together with 30-100 grams of oxide inclusions per ton of steel, said inclusions comprising 40-60% SiO 2 , 5-30% CaO and 25-40% Al 2 O 3 , with less than 20% of other oxides, said inclusions having a melting point of 1,200°-1,600° C.
Claim 3
Dependent Claim
28 words
Steel as claimed in claim 1 in which said oxide inclusions comprise less than 15% of oxides other than CaO, Al 2 O 3 and SiO 2 .
Claim 4
Dependent Claim
13 words
Steel as claimed in claim 1 in which said selected element is lead.
Claim 5
Dependent Claim
13 words
Steel as claimed in claim 1 in which said selected element is sulfur.
Claim 6
Dependent Claim
15 words
Steel as claimed in claim 1 which comprises 0.30-4.50% nickel, 0.15-3.50% chromium, and 0.08-1.0% molybdenum.
References Cited (Backward Citations)
GB1049917A
Cited
US3630723A
Cited
US3652267A
Cited
US3634074A
Cited
US3948649A
Cited
US3844773A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-09-18 | 1982-03-20 | 1982-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-18 | 1986-03-20 | 1986-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-18 | 1990-03-20 | 1990-09-19 | $7700.00 | Window Closed / Lapsed |