Impact treatment method for improving fatigue characteristics of welded joint, impact treatment device for improving fatigue characteristics for same, and welded structure superior in fatigue resistance characteristics
US8776564B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 2009 |
| Grant date | Jul 15, 2014 |
| Priority date | — |
| Expiry date | Sep 12, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12347
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An impact treatment method for improving fatigue characteristics of a welded joint comprising pressing an impact pin against the surface of a base metal material near a toe of a weld bead and making it move relatively to the weld line direction to apply hammer peening treatment or ultrasonic impact treatment, characterized by using as the impact pin an impact pin having a tip curvature radius of ½ or less of a thickness of the metal material and between 2 to 10 mm and, on a surface of a base metal material up to a range where a distance from the toe of the weld bead to the center of the impact treatment position is within 2.5 times the tip curvature radius of the impact pin and where the impact pin does not contact the weld metal during impact treatment, applying hammer peening or ultrasonic impact treatment so as to cause by the impact pin residual plastic deformation where an impact dent has a groove depth of 0.1 to 2 mm, the tip curvature radius of the impact pin or less, and 1/10th or less of the thickness of the metal material and where the impact dent has a width of 1.5 to 15 mm and five times or more the groove depth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.