Method for producing rail
US11111555B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 2018 |
| Grant date | Sep 7, 2021 |
| Priority date | — |
| Expiry date | Nov 15, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/42
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A rail achieves a high 0.2% proof stress after straightening treatment, the high 0.2% proof stress being effective at improving rolling contact fatigue resistance of the rail, by hot rolling a steel raw material to obtain a rail, the steel raw material having a chemical composition containing C: 0.70% to 0.85%, Si: 0.1% to 1.5%, Mn: 0.4% to 1.5%, P: 0.035% or less, S: 0.010% or less, and Cr: 0.05% to 1.50% with the balance being Fe and inevitable impurities; straightening the rail with a load of 50 tf or more; and subsequently subjecting the rail to heat treatment in which the rail is held in a temperature range of 150° C. or more and 400° C. or less for 0.5 hours or more and 10 hours or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.