Method for improving residual stress in tubular body
US8637784B2 · kind B2 · utility
Assignees
- Mitsubishi Electric Corporation
- THE JAPAN ATOMIC POWER COMPANY
- HOKKAIDO ELECTRIC POWER CO., INC.
- TOHOKU ELECTRIC POWER COMPANY, INC.
- TOKYO ELECTRIC POWER COMPANY HOLDINGS, INCORPORATED
- CHUBU ELECTRIC POWER COMPANY, INCORPORATED
- HOKURIKU ELECTRIC POWER COMPANY
- The Kansai Electric Power Co., Inc.
- THE CHUGOKU ELECTRIC POWER CO., INC.
- SHIKOKU ELECTRIC POWER CO., INC.
- KYUSHU ELECTRIC POWER CO., INC.
- ELECTRIC POWER DEVELOPMENT CO., LTD.
Inventors
Key dates
| Filing date | Jan 11, 2008 |
| Grant date | Jan 28, 2014 |
| Priority date | — |
| Expiry date | Nov 25, 2030 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D1/09
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An object is to provide a method and an apparatus for improving a residual stress in a tubular body, which are enabled to improve the residual stress reliably by clearly defining controlling rage for treatment conditions without depending on an installation state and configuration of the tubular body. When a cylindrical tubular body (2) is improved in its residual stress by locally irradiating an outer-circumferential surface of a welded portion (C) of the tubular body (2) with laser beams (5a) and by moving an irradiation area (s) in an circumferential direction, a plurality thermocouples (9) are installed on the tubular body (2) to be improved, a temperature history of the outer surface of the tubular body (2) by the irradiation of the laser beam (5a) is managed by measuring the temperature history itself.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.