A Metallurgical Approach to Grinding Ball Production
J. G. UNDER WOOD
The wear performance of grinding balls under conditions of impact and abrasion is affected by their chemical composition and structure. The selection of appropriate analyses and heat treatments that will provide both abrasion al}d impact resistance takes into account the effects of certain elements on structure and hardenability, as well as the over-all effect of composition and hardness penetration on the residual stress pattern developed through heat treatment. Direct quenching from forging temperatures substantially increases hardenability over that obtained in reheat-quench practices, and can be done without undue risk of damage to the ball provided that the hardenability bears the correct relationship to ball diameter. Average volumetric hardness and percent hardened volume are convenient parameters for quantitatively expressing the response to heat treatment and indicating anticipated wear properties. A number of factors which can lead to reduced wear life as a result of material or processing problems are reviewed and illustrated.
Mots Clés:
Balls, Bars, Carbon, Grinding, hardenability, hardness, heat treatment, quenching, residual stress, Hardness, steel, Steels, Temperature
