What kind of low chromium forging is cost effective

Release time:2021-02-04     Views

  1、 Technical indicators of quality requirements:

  1. Low cement ball consumption per unit: the low chromium forging index is related to the grindability of the material to be grinded, and more to the correct selection of parameters and grinding aids. But after these factors are relatively fixed, the hardness of the steel ball itself becomes an important index to judge the performance of the steel ball. Generally, the Rockwell hardness HRC is greater than 62, and the final consumption of cement steel ball per ton should be less than 30g, and the current index is not greater than 15g / T. Obviously, the service life of the latter will be twice that of the former. The application practice of many cement enterprises has proved that the steel ball with high hardness has high rigidity and no energy consumption of elastic buffer, which is very helpful to improve the output of the mill and the specific surface area of the product under the same grinding time.

  The realization of this index not only depends on the correct proportion of raw material composition of steel ball, but also has an important relationship with molding pouring process and heat treatment process. Users should not easily believe the ratio of high chromium and high nickel promised by the manufacturer, but should randomly take samples and send them to qualified inspection department for inspection; they should not easily believe the pouring and heat treatment processes introduced by the manufacturer, but should know the support facilities and equipment capabilities of the manufacturer to implement these processes on the spot; they should also investigate the actual application data of users who have used their products.

  2. Broken ball rate: when the hardness of the steel ball is high, the toughness decreases and the brittleness increases correspondingly. Especially when the heat treatment is not good, the residual stress is greater, which makes the steel ball burst. The cracked steel ball not only can not play a good role in grinding, but also increases the wear of other steel balls. Therefore, the excellent foundry should carry out the impact test of AK value to ensure that the value should be more than 5% - 7%, which is another important index to inspect the quality of steel ball. At the same time, metallographic microscope should be used to detect that the number of grains per square millimeter should reach 70000-80000. The more and more homogeneous the grains are, the higher the toughness of the material is. Only after these tests can the broken ball rate not be greater than 1%.

  The broken ball rate is also related to the storage and use conditions of steel balls

  (1) the steel balls shall not be piled up in the open air, exposed to the sun and rain, and the ambient temperature shall not change dramatically.

  (2) proper materials should be fed into the mill before starting the grinding of low chromium section, and excessive grinding should not be carried out before stopping the grinding. For this reason, it is not advisable to smash the materials in the mill empty in order to replace the grinding cement varieties. The correct way is to strictly control the low-grade varieties from entering the high-grade variety storehouse when they are transferred to the storehouse, and prefer to sacrifice some high-grade varieties of cement for sale as low-grade cement. In order to clear the storehouse and pour the ball, it is also not necessary to smash the grinding for too long. Before clearing the warehouse and pouring the ball, it should be carried out after proper ventilation and cooling.

  (3) in the process of operation, it is necessary to pay attention to reasonable ball distribution, maintain a certain high material ball ratio, and reasonably control the filling rate of materials and steel balls in the mill. Therefore, it should be avoided to reduce the feed excessively in order to reduce the product fineness.

  (4) steel balls of different quality and brands should not be used in mixed warehouse.


  3. If the surface of the steel ball is smooth and the area of the pouring riser is small, the invalid wear of the steel ball at the pouring riser can be reduced, and the energy consumption can be reduced and the output can be increased. This is one of the main standards to identify the casting level owned by the manufacturer.

  2、 The requirements for a high cost performance steel ball manufacturer are as follows:

  (1) advanced casting technology and equipment: the international advanced anhydrous production process is adopted, that is, completely dry resin sand is applied on the metal film to completely eliminate the casting defects such as porosity and slag inclusion that may be caused by water glass moisture, so that the product quality has a qualitative leap; the iron carbon ratio is improved to fully meet the quenching requirements.

  (2) the enterprise has a perfect quality assurance system, and seriously implements the inspection and control procedures of product quality: the chemical composition of raw materials entering the factory must be analyzed, and the unqualified products must be returned; it has a high-performance spectrometer, which can analyze the molten steel before pouring, and when the main element content is unqualified, it can not pour; the inspection method of finished products is: it has Rockwell hardness tester can carry out sampling test on the hardness of steel balls; each batch of steel balls shall be subject to sampling cutting inspection and non-destructive testing before leaving the factory to judge the porosity inside the steel balls; fatigue ball falling test shall be carried out on the steel balls regularly to ensure no cracking and peeling in more than 5000 times.

On:Selection of grinding medium hardness under different working conditions

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