Steel material for carburized bearing part
US11168387B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Aug 24, 2018 |
| Grant date | Nov 9, 2021 |
| Priority date | — |
| Expiry date | Nov 17, 2038 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16C2240/90
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The steel material for a carburized bearing part according to the present invention contains, by mass %, C: 0.25 to 0.45%, Si: 0.15 to 0.45%, Mn: 0.40 to 1.50%, P: 0.015% or less, S: 0.005% or less, Cr: 0.60 to 2.00%, Mo: 0.10 to 0.35%, V: 0.20 to 0.40%, Al: 0.005 to 0.100%, Ca: 0.0002 to 0.0010%, N: 0.0300% or less and O: 0.0015% or less, with the balance being Fe and impurities, and satisfies Formulae (1) to (3). 1.20<0.4Cr+0.4Mo+4.5V<2.75 (1)A1/A2>0.50 (2)2.7C+0.4Si+Mn+0.45Ni+0.8Cr+Mo+V>2.55 (3) Formula (2) shows an area fraction of sulfides containing Ca in an amount of 1 mol % or more among sulfides having an equivalent circular diameter of 1 μm or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.