High-hardenability big-diameter 65MnCr grinding ball and preparation method thereof

Abstract

The invention provides a high-hardenability big-diameter 65MnCr grinding ball and a preparation method thereof, which belong to the field of wear-resistant materials. The grinding ball consists of the following components in percentage by weight: 0.55-0.75% of C, 0.1-0.5% of Si, 1.0-3.0% of Mn, 0.5-1.5% of Cr, 0.01-0.1% of Al, less than or equal to 0.1% of P, less than or equal to 0.01% of S, less than or equal to 0.01% of N and the balance of unavoidable impurities. The preparation technology comprises the following steps: heating a steel billet at temperature of 1050-1100 DEG C, preserving heat for 1 hour, soaking, milling the steel billet on a two-roll mill, placing the steel billet in water with temperature of 900-950 DEG C, quenching for 2.5-3 minutes in water, at grinding ball re-reddening temperature of 120-150 DEG C, then preserving heat for 6 hours in a furnace at temperature of 320-400 DEG C, and taking the steel billet out and cooling in heap. After tempering, internal stress is eliminated, impact toughness is enhanced and non-notched impact energy at normal temperature is over 25 J. The production technology is simple and feasible to operate, the produced 65MnCr grinding ball has very good hardenability as well as excellent matching of hardness and toughness, and the production can achieve practical industrial application.

Description

technical field [0001] The technology relates to a large-diameter 65MnCr grinding ball with high hardenability and a preparation method thereof, which mainly involves preparing a large-diameter grinding ball with high hardenability, high hardness and high toughness. technical background [0002] Grinding balls are the wearable parts with the largest consumption in ball mills used to crush ores, coal mines, etc. They are widely used in milling equipment in metallurgy, mining, electric power, building materials and other industrial fields. The annual consumption in my country is more than 1.5 million tons. Improving the service life of wearing parts and reducing production costs have always been valued by research and production departments at home and abroad. In recent years, with the increase of energy costs and the decline of various ore grades, construction investment and production costs are a serious problem faced by mines all over the world. Due to the use of efficient l...

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Problems solved by technology

For large-diameter grinding balls, there is a non-negligible difference in the cooling rate at different positions, so continuous cooling to the bainite zone and continuous cooling to obtain the cooling rate of the bainite and martensite multiphase structure Cannot achieve accurate control

There are certain differences in hardness and toughness at different positions, and the performance of the grinding ball is unstable. At the same time, the process is complicated and it is not easy to control and prepare

[0004] In the case that the above-mentioned wear-resistant materials and processes cannot meet the performance of large-diameter grinding balls, reasonable composition and process design are required to produce grinding balls with high hardness and toughness.

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