Detection of rolling contact fatigue
US6964202B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 2002 |
| Grant date | Nov 15, 2005 |
| Priority date | — |
| Expiry date | Sep 16, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2203/0635
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The onset of rolling contact fatigue in an object may be detected by measuring the residual stresses in the surface of the object, and monitoring changes in their magnitude or their direction. The values of residual stresses in the surface are those averaged over a depth that may be in the range say 0.1 mm to 8.0 mm, for example about 2.5 mm. For ferromagnetic objects such as rails, the method may utilize an electromagnetic probe. Prior to rolling contact fatigue the surface stresses are compressive, and the onset of rolling contact fatigue may be characterized by a marked decrease of the stress in the generally transverse direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.