High-strength pearlitic steel rail having excellent delayed fracture properties
US8361382B2 · kind B2 · utility
2Cited by
1References
4Claims
0Family size
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Key dates
| Filing date | Nov 18, 2011 |
| Grant date | Jan 29, 2013 |
| Priority date | — |
| Expiry date | Nov 18, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/18
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A steel rail including a composition of, in mass percent, C of 0.6% to 1.0%, Si of 0.1% to 1.5%, Mn of 0.4% to 2.0%, P of 0.035% or less, S of 0.010% or less, Ca of 0.0010% to 0.010%, and the remainder being Fe and inevitable impurities, wherein the tensile strength is 1200 MPa or more, and the size of a long side of a C type inclusion is 50 μm or less in at least a cross-section in a longitudinal direction of a rail head, and the number of Ca type inclusions, each having a size of a long side of 1 μm to 50 μm, is 0.2 to 10 per observed area of 1 mm2 in the cross-section in the longitudinal direction of the rail head.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.