Control of steel water flow from middle package
Steel water is an important material in the process of hot rolling of steel. Its quality, flow and temperature are important to guarantee the quality of hot-rolled products. The main flow control of steel water is realized by the middle pack of the hot mill. The middle pack is one of the important measures to improve the product quality of high-grade steel. It is unique and innovative. The following is a brief introduction to the steel water flow control of the middle package.
The middle package is located between the last two hot rolling mills. The original purpose of the middle package is to increase the rolling section and reduce the temperature and speed of rolling. When its cold, it is used to pre-heat the surface and ensure a high temperature of rolling. The medium package of hot rollingmill is usually a small and medium size package, usually containing middle guide roll, guide roller, guide plate and control bushing. During hot rolling, the guide roll and guide plate can regulate the profile and thickness of the slab, and ensure the accuracy of the rolling section. The guide roller is used to limit the pre-bending of the slab, prolong the service life of the guide plate, and generate jet flow of the slab in the rolling direction by controlling the gap of the guide roller.
The middle package of hot rollingmill not only has the function of pre-straightening, preheating and section adjustment of the cold-rolled material, but also has the function of controlling steel water. When steel sheets of different specifications and temperatures enter the middle pack, the guide roller of the middle pack is used to control the gap of the middle guide roller and the side guide roller, so as to control the steel water velocity and the amount of steel water flow. Different types of rolls and different edge guide gap sizes can ensure that the amount of steel water flow can adjust according to the change of section size. When the flow of steel water is uncontrolled, it will cause the surface of the material to have different shapes and affect the uniformity of surface quality.
The correct control of steel water flow in the middle package directly affects the quality of steel products, including two aspects：one is the surface quality, the other is the shape accuracy. For example, when the edge guide gap is too large, the steel water will flow with too high speed, and the steel water particles will be adsorbed on the surface of the material, forming uneven surface roughness and affecting the quality of the surface. If the edge guide gap is too small, the steel flow will be too slow, and it will cause the steel water particles to accumulate on the surface of the material, resulting in slag spots, burrs and discoloration on the surface, which will also affect the quality of the surface.
Therefore, controlling the flow of steel water in the middle package is an important task. Accurate calculation and selection of rolls and gap sizes of edge guide rollers is necessary. Appropriate adjustment of the gap size of the edge guide rollers can ensure that the amount of steel water flow meets the needs of different section sizes. Furthermore, with the combination of advanced control technology and automatic control technology, the dynamic control and optimization of steel water flow used in hot rolling mill can be realized in real time, which can further improve product quality and product competitiveness.
