What low chromium section is more cost-effective

Release time：2020-06-15 I.Technicalindicatorsofqualityrequirements:1.Lowcementballconsumptionperunit:theindexoflowchromiumsectionisrelatedtothewearabilityofthematerialtobeground,aswellastheselectionofcorrectparametersandgrin...

　　I. Technical indicators of quality requirements:

　　1. Low cement ball consumption per unit: the index of low chromium section is related to the wearability of the material to be ground, as well as the selection of correct parameters and grinding AIDS. However, 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 performance is that the consumption of tons of cement steel ball should be less than 30g. The current index is no more than 15g/t. Obviously, the latter will last twice as long as the former. The application practice of many cement enterprises shows that the steel ball with high hardness has high rigidity and no elastic buffer energy consumption, which is very beneficial to increase the mill output and increase the specific surface area of the product under the same grinding time.

　　The realization of this index not only depends on the correct composition of steel ball, but also has an important relationship with the forming pouring process and heat treatment process. Users should not easily believe the high chromium and nickel ratio promised by the manufacturer, but random samples should be sent to a qualified inspection department for inspection; Do not easily believe the pouring and heat treatment process introduced by the manufacturer, but should know the manufacturer's support facilities and equipment capacity to implement these processes; More importantly, investigate the actual application data of the users who have already used their products.

　　2. Ball crushing rate: when the hardness of the steel ball is high, the toughness decreases and brittleness increases accordingly. Especially when the heat treatment is not good, the internal residual stress will be greater, making the steel ball burst. The steel ball not only can not play a good grinding effect, but also increases the wear of other steel balls. Therefore, a good foundry should carry out the AK value impact test to ensure that the value should be above 5%-7%, which is another important index to check the quality of steel ball. At the same time, the number of grains per square millimeter should be measured by metallographic microscope, which indicates the higher toughness of the material. Only after these tests, can we ensure that the ball breaking rate after the use of the ball is not more than 1%.

　　The breaking rate is also related to the preservation and use conditions of the user's steel balls:

　　1 steel ball should not be piled up in the open, should not be exposed to the sun and rain, environmental temperature should not be drastic changes.

　　The low chromium section before the start of grinding should feed into the appropriate material, stop grinding before do not go too far. For this reason, the kind of in order to replace the variety of grinding cement and will be ground material empty method is not desirable, the correct way is to strictly control the low-grade varieties in the warehouse do not enter the high-grade varieties in the warehouse, would rather sacrifice some high-grade varieties of cement, in order to sell as low-grade cement; In order to clear the ball, also do not "smash" for too long. Before clearing the ball, it should be properly ventilated and cooled.

　　(3) In the running process to pay attention to the reasonable distribution of ball, maintain a certain high material ball ratio, reasonable control of the filling rate of materials and steel ball in the mill. For this reason, excessive reduction of feeding methods in order to reduce the fineness of the product should be avoided.

　　Of different quality, brand of steel ball do not mix warehouse use.

　　3. The surface of the steel ball is required to be smooth, and the area of the spout and riser is small in the total surface area of the steel ball, which can reduce the ineffective wear of the steel ball at the spout and riser, and is also conducive to reducing energy consumption and increasing production. This is one of the main criteria for identifying the level of casting owned by the manufacturer.

　　Ii. High cost performance Steel ball manufacturers shall have the following conditions:

　　(1) advanced casting technology equipment: the use of international advanced non-hydration production process, namely the use of completely dry resin sand applied on the metal film, completely eliminate the water glass water may cause the porosity, slag and other casting defects, so that the product quality has a qualitative leap; The ratio of iron to carbon is improved to meet the quenching requirement.

　　The enterprise has a perfect quality assurance system, the careful implementation of product quality inspection and control procedures: the raw materials into the factory must be analyzed chemical composition, rejected returns; It has a high performance spectrometer, which can analyze the molten steel before pouring in each furnace, and cannot pour when the content of main elements is unqualified. The inspection method for factory finished products is: possessing rockwell hardness tester, the hardness of steel ball can be sampled; Sampling cutting inspection and nondestructive inspection are conducted for each batch of steel ball before delivery to judge the porosity inside the ball; Regular fatigue ball falling experiment on the steel ball to ensure no cracking and peeling in more than 5000 times.