US3844773A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Free cutting steel containing mullite
Assignee: Kobe Steel Ltd
•
Filing: 1973-05-10
•
Granted: 1974-10-29
•
Expires: 1993-05-10
Abstract
Abstract A free cutting steel is disclosed having improved cutting properties which leads to improved service life for cutting tools. Th steel is characterized by the presence of a principal component of a nonmetallic inclusion contained within said steel existing essentially in the mullite region of three phase trigonometric diagram of the CaO-Al2O3-SiO2 system. The steel also contains 5 to 15 ppm calcium and 0.04 to 0.15 percent sulfur as elements which enhance the cutting properties of said steel. This steel exhibits excellent cutting properties both at high speed cutting using a cemented carbide tool (a super-hard cutting tool) and at low speed cutting using a tool of a high speed steel.
Inventors
- 👤 N Yamakoshi
- 👤 K Narita
- 👤 T Fujita
- 👤 T Kaneda
- 👤 Y Yanagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 04:18
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/60
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
80 words
A FREE CUTTING STEEL WHICH CONTAINS 0.10 TO 0.60 PERCENT CARBOB, 0.50 TO 0.40 PERCENT SILICON, 0.04 TO 0.15 PERCENT SULPHUR, AND IS CALCIUM DEOXYGENATED BY THE ADDITION OF 5 TO 15 PPM CLACIUM WHICH FORMS NON-METALLIC INCLUSION OF A COMPOSITION CONSISTING ESSENTIALLY OF THE MULLITE REGION OF A THREE PHASE TRIGONOMETRIC DIAGRAM OF THE CAO-AL2O3-SIO2 SYSTEM, WHEREBY SAID FREE CUTTING STEEL EXHIBITS SUPERIOR CUTTING PROPERTIES BECOMES OF THE PRESENCE OF SAID NONMETALLIC INCLUSIONS, SAID CALCIUM AND SAID SULFUR THEREIN.
Claim 2
Dependent Claim
80 words
A FREE CUTTING STEEL WHICH CONTAINS 0.10 TO 0.60 PERCENT CARBOB, 0.50 TO 0.40 PERCENT SILICON, 0.04 TO 0.15 PERCENT SULPHUR, AND IS CALCIUM DEOXYGENATED BY THE ADDITION OF 5 TO 15 PPM CLACIUM WHICH FORMS NON-METALLIC INCLUSION OF A COMPOSITION CONSISTING ESSENTIALLY OF THE MULLITE REGION OF A THREE PHASE TRIGONOMETRIC DIAGRAM OF THE CAO-AL2O3-SIO2 SYSTEM, WHEREBY SAID FREE CUTTING STEEL EXHIBITS SUPERIOR CUTTING PROPERTIES BECOMES OF THE PRESENCE OF SAID NONMETALLIC INCLUSIONS, SAID CALCIUM AND SAID SULFUR THEREIN.
Claim 3
Dependent Claim
42 words
The free cutting steel of claim 1, wherein said free cutting steel further contains at least one alloy component selected from the group consisting of 0.03 to 1.50% Mn, up to 2.00% Cr, up to 0.50% Mo, and up to 2.00% Ni.
Claim 4
Dependent Claim
17 words
The free cutting steel of claim 1, wherein said steel further contains 0.025 to 0.100 percent niObium.
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) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |