Low carbon calcium-sulfur containing free-cutting steel
US3973950A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 1975 |
| Grant date | Aug 10, 1976 |
| Priority date | — |
| Expiry date | Sep 12, 1995 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/60
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Low carbon calcium-sulfur containing free-cutting steel exhibiting improved machinability is disclosed. The said steel consists essentially of 0.03 to 0.10% carbon, up to 0.3% silicon, 0.8 to 1.5% manganese, 0.04 to 0.10% phosphorus, 0.20 to 0.45% sulfur, 0.0003 to 0.0050% calcium and the remainder being iron and inherent impurities such as copper, nickel, chromium and nitrogen; and is prepared by regulating the composition of the steel so that the value of theoretical Brinell hardness of the steel matrix, which is determined on the basis of the content of carbon, silicon, manganese, phosphorus, sulfur, copper, nickel, chromium and nitrogen in the steel, to a value between 110 and 130, and by forming and maintaining in the range of from 100 to 500 grams per steel-ton oxide inclusions of type JIS-A2 (ASTM-C) which soften or fuse at a temperature not higher than 1400.degree.C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.