Steel having superior rolling fatigue life
US10060013B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 2014 |
| Grant date | Aug 28, 2018 |
| Priority date | — |
| Expiry date | Mar 4, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/004
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
There is provided a steel, having an excellent rolling fatigue life, wherein an oxygen content in the steel is 8 ppm or less, a sulfur content is 0.008 mass % or less, and an Al content is 0.005 to 0.030 mass %, the number of non-metallic inclusions having an inclusion diameter of 20 μm or more and less than 100 μm, detected per steel material volume of 1000 mm3 by ultrasonic flaw detection, is 12.0 or less, the number of non-metallic inclusions having an inclusion diameter of 100 μm or more, detected per steel material weight of 2.5 kg by the ultrasonic flaw detection, is 2.0 or less, the mass % ratio of (MgO)/(Al2O3) in the average composition of MgO—Al2O3-based oxides present in the steel is regulated into a range of 0.25 to 1.50, and the number ratio of the MgO—Al2O3-based oxides to all oxide-based inclusions is 70% or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.