Solutions to 6 major problems related to emulsions such as thermal scratches, slippage, and blackening in rolling production!
February 07, 2022
The modern cold rolling process is pursuing the development of large pressure, high speed and continuous direction, and the lubrication and cooling effect of the emulsion cannot be ignored. With the competition in the market, process lubrication plays an important role in saving energy and reducing consumption and improving the surface quality of products. The lubrication and cooling effect of the emulsion is the technical core of the cold rolling lubrication process. Understanding the influencing factors of the performance parameters of the emulsion and controlling it reasonably can improve the rolling lubrication effect and ensure the smooth rolling.
In the actual use process should pay attention to: (1) The magnetic and backwash filters of the lubricating process system are the key to ensuring the cleanliness of the emulsion itself, and should be opened frequently to check whether it is running normally;
(2) During the use of the emulsion, it is also an important prerequisite to achieve good process lubrication to quickly adjust the fluctuations of parameters such as concentration, saponification value, PH value and iron powder content that affect its lubricating effect.
(3) In the production process, according to different varieties and specifications of rolling materials, different rolling mills and work rolls, the concentration, temperature and flow parameters of the emulsion are taken as the research objects to optimize the lubrication process. To improve the lubrication and cooling effect, it is extremely important to guide production. significant.
(4) Since the environmental protection index of the emulsion waste liquid does not meet the discharge standards stipulated by the state, the amount of waste liquid treatment is greatly increased, the treatment cost is also increased accordingly, and the processing cost is increased. Cold rolling lubricants are of great significance.
Problems and solutions related to emulsion in rolling production 1. Thermal scratches Too thin oil film thickness or too little oil film is the main reason for thermal scratches. Its solution: 1) Increase the concentration of the emulsion; 2) Increase the temperature of the emulsion; 3) Increase the injection volume (flow) of the emulsion; 4) Use rolls with larger diameters; 5) Reduce the roughness of the roll surface; 6) Increase the iron content in the emulsion (ie, open the magnetic bar less). 2. Slip Contrary to the phenomenon of thermal scratching, if the thickness of the oil film is too large, or the range of fluid lubrication increases, and the friction coefficient decreases below a certain bond, slipping will occur. Its solution: 1) Reduce the concentration of the emulsion; 2) Reduce the temperature of the emulsion; 3) Reduce the content of iron powder in the emulsion (such as open magnetic rod filter, oil sprinkler, etc.); 4) Increase the surface roughness of the roll. 3. The board surface is black Among the ratios of oil content and iron content on the surface of the steel sheet after rolling, the higher iron content ratio causes the blackening of the plate surface. Its solution: 1) Increase the temperature and concentration of the emulsion; 2) Reduce the iron content in the emulsion; 3) Reduce the surface roughness of the roll. 4. Vibration In terms of lubrication, it is caused by "lubricity marks", that is, the rolling oil involved in the roll gap does not reach a uniform state, and the friction coefficient of the uneven part is quite different from that of other places. Its solution: 1) Increase the temperature of the emulsion; 2) Increase the surface roughness of the roll. 5. Rust and emulsion spots Due to the bad shape of the strip, the emulsion carried out is involved in the steel coil, and the water on the surface of the strip is not completely removed, both of which may cause emulsion spots. High ambient air temperature or high concentration of hydrochloric acid will cause point rust to occur. Its solution: 1) Increase the amount of air purging; 2) Increase the temperature of the emulsion; 3) Increase the concentration of the emulsion; 4) Improve the working environment around the rolling. 6. Rolling force rises If the rolling reduction is too large and the material is hard, it is easy to cause the rolling force to rise. Its solution: 1) Appropriately increase the temperature and concentration of the emulsion; 2) Reduce the surface roughness of the roll, and use a small roll diameter for rolling. The above-mentioned first six problems can also be solved by improving the variety of rolling oil.
