Carburized component and manufacturing method
US8961710B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Nov 28, 2011 |
| Grant date | Feb 24, 2015 |
| Priority date | — |
| Expiry date | Nov 28, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/24
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A carburized component with improved fatigue strength has a base steel containing, by mass %, C: 0.15-0.25%, Si: 0.03-0.50%, Mn: more than 0.60% and not more than 1.5%, P≦0.015%, S: 0.006-0.030%, Cr: 0.05-2.0%, Al≦0.10%, N≦0.03%, and O≦0.0020%, and optionally at least one element selected from Mo, Cu, Ni, B, Ti, Nb and V, the balance being Fe and impurities. A surface hardened layer portion satisfies: (a) average carbon concentration in the region from the outermost surface to a point of 0.2 mm depth of 0.35-0.60 mass %, (b) surface roughness Rz≦15 μm, and (c) σr(0)≦−800 MPa, σr(100)≦−800 MPa, and residual stress intensity index Ir≦80000, wherein Ir is calculated by [Ir=∫|σr(y)|dy], where y μm is the depth from the outermost surface and σr(y) is the residual stress for the points from the outermost surface to a depth of 100 μm with the range of y from 0 to 100 (μm).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.