Internal high hardness type pearlitic rail with excellent wear resistance and rolling contact fatigue resistance and method for producing same
US7955445B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 2008 |
| Grant date | Jun 7, 2011 |
| Priority date | — |
| Expiry date | Mar 25, 2028 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/009
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An internal high hardness type pearlitic rail that has a composition containing 0.73% to 0.85% by mass C, 0.5% to 0.75% by mass Si, 0.3% to 1.0% by mass Mn, 0.035% by mass or less P, 0.0005% to 0.012% by mass S, 0.2% to 1.3% by mass Cr, and the balance being Fe and incidental impurities, in which the value of [% Mn]/[% Cr] is greater than or equal to 0.3 and less than 1.0, where [% Mn] represents the Mn content, and [% Cr] represents the Cr content, and in which the internal hardness of a rail head that is defined by the Vickers hardness of a portion located from a surface layer of the rail head to a depth of at least 25 mm is greater than or equal to 380 Hv and less than 480 Hv.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.