Methods and apparatus for detection of crack initiation
US5883311A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 1996 |
| Grant date | Mar 16, 1999 |
| Priority date | — |
| Expiry date | Jun 21, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2203/0246
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Methods and apparatus for detecting the onset of stress corrosion cracking are described. In one aspect, the present invention is a passive detector for in-situ detection of the onset of stress corrosion cracking in a nuclear reactor. The detector includes a ceramic insulator mounting member. A first material sample and a second material sample are secured to the mounting member. In the one embodiment, a metal bolt extends through the first and second material samples and secures the samples to the mounting member. The first material sample is cold worked to induce residual tensile stress and the second material is not cold worked. A first electrical conductor is electrically connected to the first material sample and a second electrical conductor is electrically connected to the second material sample. An electrometer is electrically connected to the first and second electrical conductors, and the electrometer is configured to generate a strain induced differential potential signal representative of a difference in potential between the first sample and the second sample. Alternatively, a strain induced differential current signal can be monitored using a zero resistance ammeter i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.