GRINDING MEDIA FABRICATION

摘要

A steel ball for use as grinding media in a mill, and a method of fabricating such ball are disclosed. The steel ball has the following composition, by weight Carbon 1.05% ~ 0.05 Silicon 0.55% ~ 0.45 Manganese 0.75% ~ 0.60 Chromium 0.90% ~ 0.60 Molybdenum 0.20%~ 0.20 Phosphorous 0.15%~ 0.15 Sulphur 0.015%~ 0.015 Nickel 0.225%~ 0.225 Copper 0.225%~ 0.225 Vanadium 0.05%~ 0.05 Aluminium 0.05%~ 0.05 with the balance being iron. The ball has an average surface hardness of 60-65 HRC and an average volumetric hardness of 59-65 HRC. The ball has a tempered martensitic microstructure and is formed by heating a billet, forging the billet to form a substantially spherical ball, quenching and then tempering the ball.