Low-chromium hard-wearing grinding ball and processing technology thereof

Abstract

The invention discloses a low-chromium hard-wearing grinding ball and a processing technology of the low-chromium hard-wearing grinding ball. The low-chromium hard-wearing grinding ball comprises, by mass, 3.60-3.70% of C, 3.05-3.15% of Si, 1.48-1.53% of Mn, 0-0.05% of P, 0.005-0.009% of S, 0.02-0.03% of RE residue (Y), 0.03-0.043% of Mg residue, 0-0.15% of Cr, 0-0.28% of V, 0-0.10% of Ti, 0-0.005% of B, 0-0.40% of Cu and the balance Fe. The low-chromium hard-wearing grinding ball is prepared through the CADI grinding ball continuous type isothermal quenching and oil cooling special line, and the processing technology comprises the stages of preheating, primary heating, secondary heating, temperature equalization, precooling temperature equalization, isothermal cooling and air cooling. The low-chromium hard-wearing grinding ball is high in impact toughness value and hardness value, long in impact fatigue service life, low in chromium content, environmentally friendly and safe. According to the production technology, the steps are simple and stable, the heating and cooling temperature and time in each stage are strictly controlled, the oil cooling technology is adopted in the quenching process, the processing performance of the product is ensured, production efficiency is high, and the product quality is good.

Description

technical field [0001] The invention relates to the field of grinding ball castings, in particular to a low-chromium wear-resistant grinding ball and a processing technology thereof. Background technique [0002] Grinding balls are mainly used in mining, cement, profitable power generation and other fields. According to experts' estimates, the domestic annual consumption is about 1.6 million tons. At present, casting grinding balls are mainly chrome balls. At present, the national standard hardness of CADI casting grinding balls in China is ≥50HRC. There is no regulation on the impact toughness index. Some domestic manufacturers and research departments believe that the impact toughness value is ≥ 8J / cm 2 , can meet the requirements of use. The impact toughness index of traditional cast grinding balls, namely chromium balls, is 4-5J / cm 2 , so there is a certain breakage rate, which is not very ideal when used; the impact toughness index of individual CADI grinding ball manu...

AI Technical Summary

Problems solved by technology

[0002] Grinding balls are mainly used in mining, cement, profitable power generation and other fields. According to experts' estimates, the domestic annual consumption is about 1.6 million tons. At present, casting grinding balls are mainly chrome balls. At present, the national standard hardness of CADI casting grinding balls in China is ≥50HRC. There is no regulation on the impact toughness index. Some domestic manufacturers and research departments believe that the impact toughness value is ≥ 8J / cm 2 , can meet the requirements of use. The impact toughness index of traditional cast grinding balls, namely chromium balls, is 4-5J / cm 2 , so there is a certain breakage rate, which is not very ideal when used; the impact toughness index of individual CADI grinding ball manufacturers in China is 8J / cm 2 Or so, but the performance is unstable, the formula of the material, the heat treatment process, and the equipment are not very ideal, so the production capacity cannot reach the expected goal; foreign countries are still mainly cast grinding balls, that is, chromium balls, compared with CADI grinding balls , is a low-grade product with high chromium content, and chromium is more serious to environmental pollution, and the production cost of high chromium grinding balls is higher, therefore, it is necessary to improve the casting grinding balls and their processing technology of the existing technology

Images