Surface treatment method for a steel workpiece using high speed shot peening
AssigneesSuncall Corporation, Kabushiki Kaisha Fuji Seisakusho, Kabushiki Kaisha Fujikihan
InventorsYoshiro Yamada, Masaaki Ishida, Kazuhiro Uzumaki
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Abstract
Fatigue-resistance is significantly increased by performing shot peening using fine shots. A plurality of particles of hard metal having a diameter ranging from 20 to 100 micrometers are ejected onto a surface of a steel workpiece at an impinging speed greater than 80 m/second. The impinging speed is controlled so that the upper limit of temperature rising of the surface of the workpiece is maintained at a temperature more than 150.degree. C. but less than the temperature at which recovery recrystallization and austentizing of steel occurs.
Claims13
A surface treatment method for a steel workpiece comprising the steps of impinging a plurality of particles of hard metal having a diameter ranging from 20 to 100 micrometers onto a surface of the workpiece at a speed greater than 80 m/second, and controlling a temperature rise of the surface of the workpiece resulting from said impinging to a range of from greater than 150 degrees Celsius to less than the temperature at which recovery recrystallization of steel occurs.
A surface treatment method for a steel workpiece comprising the steps of ejecting shot particles having a diameter ranging from 100 micrometers to 1.0 mm onto a surface of the steel workpiece, wherein residual compressive stress is applied to the area 0.05 mm to 0.5 mm deep from the surface of the workpiece, thereafter impinging a plurality of particles of hard metal having a diameter ranging from 20 to 100 micrometers onto the surface of the workpiece at a speed greater than 80 m/second, and controlling a temperature rise of the surface of the workpiece resulting from said impinging to a range of from greater than 150 degrees Celsius to less than the temperature at which recovery recrystallization of steel occurs.
A surface treatment method for a steel workpiece comprising the steps of ejecting shot particles having a diameter exceeding 300 micrometers onto a coil spring at a speed less than 100 m/second, then ejecting shot particles having a diameter exceeding 100 micrometers but less than 300 micrometers onto the workpiece, so as to improve the surface roughness of the workpiece and residual compressive stress, and thereafter, impinging a plurality of particles of hard metal having a diameter ranging from 20 to 100 micrometers onto a surface of the workpiece at a speed greater than 80 m/second, and controlling a temperature rise of the surface of the workpiece resulting from said impinging to a range of from greater than 150 degrees Celsius to less than the temperature at which recovery recrystallization of steel occurs.
Dependencies are inferred from the claim text.