Method of production of steel product with nanocrystallized surface layer
AssigneeNippon Steel Corporation
InventorsTadashi Ishikawa, Kiyotaka Nakashima, Tetsuro Nose, Tomonori Tominaga, Yakichi Higo, Kazuki Takashima
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Abstract
A method of production of a metallic product with a nanocrystallized surface layer comprising subjecting a surface layer of a metallic product to ultrasonic impact treatment by one or more ultrasonic indenters vibrating in a plurality of directions, then subjecting the surface layer subjected to the ultrasonic impact treatment to heat treatment at a low temperature to cause precipitation of nanocrystals.
Claims17
A method of production of a steel product with a nanocrystallized surface layer,
- said method comprising the steps of:
- (1) subjecting a surface layer of a steel product to ultrasonic impact treatment by impacting it at a plurality of different directions and angles using one or more ultrasonic indenters, wherein said one or more indenters comprise three indenters joined at their tips such that the tips of the ultrasonic indenters vibrate in a plurality of different directions, with said ultrasonic impact treatment of said surface layer providing equiaxial grains in said surface layer, then,
- (2) subjecting the surface subjected to the ultrasonic impact treatment to heat treatment at 100° to 500° C. for 15 minutes or more to cause precipitation of nanocrystals.
A method of production of a steel product with a nanocrystallized surface layer,
- said method comprising the steps of:
- (1) subjecting a surface layer of a steel product to ultrasonic impact treatment by impacting it at a plurality of different directions using one or more ultrasonic indenters made to simultaneously vibrate in the vertical direction and the horizontal direction with said ultrasonic impact treatment of said surface layer providing equiaxial grains in said surface layer, then,
- (2) subjecting the surface subjected to the ultrasonic impact treatment to heat treatment at 100° to 500° C. for 15 minutes or more to cause precipitation of nanocrystals.
Dependencies are inferred from the claim text.