Production of grinding balls resistant to abrasive wear

Abstract

Low-alloy 70KhG chromium–manganese steel is investigated. The thermokinetic diagram of supercooled-austenite conversion at cooling rates 0.03–8.4°C/s is plotted. Appropriate heat treatment is developed for grinding balls of diameter 20–60 mm. The microstructure of the steel formed in heat treatment is analyzed. The temperature at which martensitic transformation begins is determined. Experimental batches of 60-mm grinding balls with bulk hardness HRC 59.5 produced by the proposed technology are tested. Their performance is excellent.