Hot Rolling Mill Machine And Cold Rolling Mill Machine

Rolling mill is the main machine of direct rolling metal. It uses rotating roll to roll billets to produce plastic deformation of metal according to the specified requirements. Rolling is a metal forming method with high productivity and low cost, which is suitable for rolling strip or plate material with the same cross section or periodic changes. Special rolling mills can roll machine parts or their blanks as well as certain non-metallic materials. The rolling mill mainly has two ways of hot rolling and cold rolling, usually the rolling process with the rolling temperature above the metal recrystallization temperature is called hot rolling, and the rolling process below the metal recrystallization temperature is called cold rolling. Hot rolling is carried out at a higher temperature to reduce the rolling pressure, which can greatly reduce the cross-sectional area of the workpiece, suitable for billet opening, cold rolling operating temperature is low, the product surface quality is good, the dimensional accuracy is high, the thickness is uniform, and can improve the mechanical properties of the rolled parts, but the equipment strength and precision are required, and the energy consumption is large.
Hot rolling is based on slab (mainly continuous casting billet) as raw material. After heating, strip steel is made by roughing mill and finishing mill. The hot steel strip from the finishing mill is cooled to the set temperature by laminar flow, and then rolled into steel strip coil by coiler. After different finishing lines (leveling, straightening, crosscutting or slitting, inspection, weighing, packaging and marking, etc.) processing into steel plate, flat coil and slitting steel strip products. To put it simply, the billet is heated and rolled several times, and then trimmed and straightened into a steel plate, which is called hot rolling.
Cold rolling with hot-rolled steel coil as raw material, after pickling to remove the oxide, cold continuous rolling, the finished product is rolled hard coil, because of the cold hardening caused by continuous cold deformation, the strength and hardness of rolled hard coil increase, toughness and plastic index decline, so the stamping performance will deteriorate, can only be used for simple deformation parts. Rolled hard coil can be used as raw material in hot dip galvanizing plant, because hot dip galvanizing units are equipped with annealing lines. The rolled hard coil weight is generally 6~13.5 tons, and the steel coil is continuously rolled for hot rolled pickling coil at room temperature. The inner diameter is 610mm. Product features: Because it has not been annealed, its hardness is very high (HRB greater than 90), the machining performance is very poor, and only a simple directional bending process of less than 90 degrees (perpendicular to the direction of winding) can be carried out.
In summary, the rolling mill as the core equipment in the field of metal processing, its diversified types and wide range of application fields, not only promote the transformation and upgrading of the traditional manufacturing industry, but also provide a solid foundation for the rapid development of emerging industries.