New development of Forging Grinding Balls production technology
Industrialization and the improvement of the quality of human life have led to the development of the whole mining industry. Grinding balls have become the necessary products for crushing and grinding of mines. At the same time, as the consumables of the industry, the cost of grinding balls has made many mining enterprises headache. Under the same conditions of miners, forging grinding ball has a certain cost advantage over chrome casting ball, so the continuous development of forged steel ball is inevitable. Up to now, the production process of forged steel ball has experienced three stages: traditional process, Cross Hot rolling and Rotary Cutting process .
The traditional forged ball, as the name implies, is the steel ball forged by forging. Air hammer is used to forge the raw materials to a certain deformation and increase the compression ratio, so as to make the structure of wear-resistant ball more dense and improve the toughness and hardness. In the traditional process, the material is first cut according to the size, then heated to a certain temperature by coal or natural gas, and then air hammer forging, heat treatment and product inspection are carried out.
There are too many disadvantages in traditional technology, among which the main ones are low production efficiency and artificial control of product quality, which are easy to cause serious environmental pollution, workers' lack of strength, thermal radiation and noise radiation, which are harmful to workers' health. The quality of steel balls is greatly affected by the labor proficiency of workers, and the quality of steel balls is uneven and cannot be guaranteed.
With the development of the times, the traditional technology has gradually faded out of the historical stage, and replaced by the oblique rolling process. The basic idea of the oblique rolling process is to heat the whole round steel with an electric furnace, send it to the roller through the conveyor, and drive the roll to rotate through the motor and reducer. The roller can use its own ball groove design to make the high-temperature round steel into a ball.
The process does not need blanking and air hammer forging, which greatly improves the production efficiency, greatly reduces the labor intensity of workers, and also greatly reduces the noise and other hazards. The oblique tie technology is a leap forward development of the forging steel ball industry. However, there are many defects in the process, such as surface quality and roundness. The surface defects of the steel ball produced by the oblique pinning technology are skin inclusion, lack of meat, over burning, protrusion and high out of roundness. Moreover, when the diameter of the steel ball is greater than 50 mm, all the indexes of the steel ball can not meet the requirements of the relevant standards. The steel ball with diameter greater than 90mm can not be produced by oblique tie technology.
With the development of mining machinery, the diameter of ball mill is becoming larger and larger. At the same time, with the emergence of semi autogenous mill, the demand of the mine for ball mill ball is gradually updated from small diameter to large diameter. Obviously, the traditional technology and inclined tie technology can not meet the needs of the mine. Some machinery company has developed an automatic rotary cutting and rolling forging production line, which can produce steel balls with a diameter of 20-150 mm. Due to the great reduction of manual intervention and process switching, the product quality between different batches has a high stability.
In the heat treatment process, the super advanced tempering and quenching process is adopted, and the advanced heat treatment process is developed by combining experts from scientific research institutions. Through multiple quenching temperature control and continuous tempering, the uniformity of volume hardness and overall wear resistance of grinding balls are better.
