Free cutting steel containing sulfide inclusion particles with controlled aspect, size and distribution
US4279646A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1979 |
| Grant date | Jul 21, 1981 |
| Priority date | — |
| Expiry date | Dec 19, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/60
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A free cutting steel for machine structural use containing C up to 0.6%, Si up to 2.0%, Mn up to 2.0%, S 0.04 to 0.4%, Te 0.002 to 0.5% and O 0.0010 0.0300%, the balance being substantially Fe exhibits excellent machinability when the MnS-based inclusion is in the form of particles of 5 to 100.mu. long, 1 to 10.mu. wide, wherein the aspect ratio length/width is not larger than 10, and at the density of 20 to 200 particles per 1 mm.sup.2 of the matrix cross section. A free cutting steel for machine structural use containing C up to 0.6%, Si up to 2.0%, Mn up to 2.0%, S 0.04 to 0.4% and Te up to 0.1%, wherein %Te/%S is at least 0.04, O up to 0.003% and N up to 0.0200%, the balance being substantially Fe exhibits improved rolling-contact fatique strength when at least 80% of sulfide-based inclusion particles of 10.mu. long or more have the aspect ratio length/width of 5 or less, and when areal percentage of alumina cluster in the matrix cross section is not higher than 0.5%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.