METHOD FOR THE PRODUCTION OF GRINDING BALLS FROM STEEL Russian patent published in 2022 - IPC C21D9/36 B21H1/14 

FIELD: rolling production.

SUBSTANCE: invention relates to rolling production, in particular to the heat treatment of grinding balls made of steel containing, wt.%: C 0.60-0.64; Mn 0.75-0.90; Si 1.75-2.00; Al 0.015-0.035; P less than 0.025; S less than 0.025; Cr 0.20-0.30; Ni less than 0.25; Cu less than 0.20; N less than 0.009; As less than 0.040; Sn less than 0.020; H less than 0.0002; Ca 0.0020-0.0030; Fe - the rest. The method includes rolling balls, cooling balls, quenching, tempering, while producing balls with a nominal diameter of 80-120 mm, and after rolling, the balls are cooled to a temperature of 670-800°C, then the balls are quenched in a quenching medium, while the hardening duration is regulated depending on the diameter of the balls: for balls with a nominal diameter of 80-100 mm from 2.5 to 4 minutes, for balls with a nominal diameter of 110-120 mm from 3.0 to 4.5 minutes, and the subsequent tempering is carried out at a temperature of 150- 270°C with holding time from 160 to 320 min.

EFFECT: invention is aimed at increasing the operational stability of the balls, obtaining grinding balls with a nominal diameter of 80-120 mm, having a bulk hardness characterized by hardness group 5 according to GOST 7524-2015.

3 cl, 3 tbl