| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel material for ultrasonic shock treatment having excellent fatigue strength, and to provide an ultrasonic shock treatment method. SOLUTION: Regarding the multi-layer steel material in which a soft layer 6 is formed on the surface 1, the thickness of the soft layer 6 is controlled to 0.1 to <1.0 mm, and also, the Vickers hardness Hvs of the soft layer 6 and the Vickers hardness Hvi of an internal layer 7 other than the soft layer 6 are allowed to satisfy equation. Then, the steel material for ultrasonic shock treatment is subjected to ultrasonic shock treatment using a leading edge tool 5 with a width R of 2.0 to 5.0 mm. COPYRIGHT: (C)2008,JPO&INPIT
|
