RU95109076A - Method of fabricating cast iron grinding balls - Google Patents

Abstract

FIELD: metallurgy. SUBSTANCE: cast iron is smelted and simultaneously alloyed. Sticks with required diameter are molded, rolled into balls, which are further hardened and tempered. Smelted cast iron is modified with magnesium-containing modifying mixture. Before rolling, sticks are heated to 950-1080 C. Balls are made on helical-rolling mill and are subjected to isothermal hardening from rolling temperature and subsequent tempering at 280-320 C. Chemical analysis of cast iron is the following (in wt %): carbon, 2.5-3.5; silicon, 1.3-2.8; manganese, 0.3-1; phosphorus, 0.02-0.08; sulfur, 0.001-0.015; copper, 0.15-0.8; chromium, 0.15-0.5; aluminium, 0.15-0.5; magnesium, 0.04- 0.08; iron, the balance. EFFECT: method provides less expensive grinding balls with high hardness, wear resistance, and shock resistance.

Claims (1)

The invention relates to metallurgy. The method consists in the fact that cast iron is melted with its alloying at the same time, rods of the desired diameter are cast from it, balls are rolled from the rods and subjected to hardening and tempering. Smelted cast iron is modified with a magnesium-containing modifying mixture, spheroidizing graphite, the rods are heated to 950-1080 ° C before rolling, the balls are obtained by rolling on a helical rolling mill, the balls obtained are subjected to isothermal hardening at a rolling temperature and subsequent tempering at 280-320 ^o С, at this use cast iron of the following chemical composition, wt. %: carbon 2.5, - 3.5; silicon 1.3 to 2.8; manganese 0.3 to 1.0; phosphorus 0.02 - 0.08; sulfur 0.001-0.015; copper 0.15-0.8; chrome 0.15-0.5; aluminum 0.15-0.5; magnesium 0.04 - 0.08; iron is the rest. The method provides for the production of grinding balls with a hardness not lower than LDC 55, high wear resistance and impact resistance at a cost of 20% lower than for steel balls.