Patent ID: 6018854
Filing Date: 2000-02-01
Classification: B22F,B24C,C21D,C22F,Y10T

Abstract:
A method of making surface-hardened metal shot, said method comprising:accommodating a predetermined quantity of shot in a first container of a blasting machine;accommodating a predetermined quantity of ferrous metal shot material in a second container of the blasting machine, the shot having a hardness that is at least equal to that of the ferrous metal shot material; andblasting the shot accommodated in the first container against the ferrous metal shot material accommodated in the second container at a speed sufficient to increase the temperature of the ferrous metal shot material in the vicinity of the surface thereof to at least an A.sub.3 transformation temperature of the ferrous metal shot material so as to harden the ferrous metal shot material and form surface-hardened metal shot.