Four methods of Grinding Steel Balls internal stress relief

A. Tempering heating method: use electric furnace, gas furnace, oil furnace to heat---cool down;

B. Residue temperature tempering method: the steel ball after forging is naturally cooled by heat preservation;

C. Impact method: adopt the ball segment separator and the drum impact method;

D. Natural failure method: natural state, stress relief (the story of the car worker is the natural failure method);