The two pressing processes of hot rolling and cold rolling for rolling mill equipment

Hot rolling takes slabs (mainly continuous casting slabs) as raw materials. After heating, they are processed into steel strips by rough rolling mills and finishing rolling mills. The hot steel strips coming out of the last stand of the finishing rolling mill are cooled by laminar flow to the set temperature and then coiled into steel strip coils by coiling machines. The cooled steel strip coils are processed through different finishing lines (leveling, straightening, cross-cutting or longitudinal cutting, inspection, weighing, packaging and marking, etc.) according to different user requirements to become steel plates, leveled coils and longitudinal cut steel strips. In simple terms, after heating, the steel billets are rolled through several passes, trimmed and corrected to become steel plates. This is called hot rolling.

Cold-rolled steel coils are made from hot-rolled steel coils as raw materials. After pickling to remove the oxide scale, they undergo continuous cold rolling. The finished product is a hard-rolled coil. Due to the cold work hardening caused by continuous cold deformation, the strength and hardness of the hard-rolled coil increase, while the toughness and plasticity indicators decrease. Therefore, the stamping performance deteriorates and it can only be used for parts with simple deformation. Hard-rolled coils can be used as raw materials for hot-dip galvanizing plants because hot-dip galvanizing lines are all equipped with annealing lines. The weight of hard-rolled coils is generally between 6 and 13.5 tons. The steel coils are continuously rolled at room temperature from hot-rolled pickled coils. The inner diameter is 610mm. Product features: As it has not undergone annealing treatment, its hardness is very high (HRB greater than 90), and the mechanical processing performance is extremely poor. It can only undergo simple directional bending less than 90 degrees (perpendicular to the coiling direction).

Rolling mills are mainly used for steel rolling, and they can be classified into semi-finished product rolling mills and finished product rolling mills. Semi-finished product rolling mills mainly include billet rolling mills, such as primary rolling mills, slab rolling mills and billet rolling mills. With the gradual promotion of continuous casting machines, some steel mills equipped with continuous casting machines no longer use billet rolling mills for billet production. Finished product rolling mills include section rolling mills, rail and beam rolling mills, wire rod rolling mills, thick plate rolling mills, thin plate rolling mills, strip rolling mills, foil and strip rolling mills, seamless tube rolling mills, copper plate rolling mills, aluminum plate rolling mills and some special rolling mills. Their main differences lie in the arrangement of the rolls and the shape of the rolls, and there are also significant differences in precision, rigidity, strength and overall dimensions. Ancillary equipment refers to a complete set of auxiliary equipment, which can be divided into auxiliary equipment for processing and auxiliary equipment for storage, transportation and packaging.

Among various types of rolling machines, the thick plate rolling machine, with its powerful rolling force and precise thickness control capability, plays an irreplaceable role in heavy machinery manufacturing, bridge construction, shipbuilding, and other fields. It can handle metal plates with large width-to-thickness ratios and high strength, and through multiple passes of rolling and temperature control, achieve the uniformity of the internal structure and the optimization of the performance of the plates. While the thin plate rolling machine and the foil strip rolling machine, with their high precision and the production capacity of thin-sized products, are widely used in automotive manufacturing, home appliance manufacturing, and precision instrument manufacturing industries, meeting the modern industrial demands for lightweight and high-strength materials.

The seamless pipe rolling machine is a key equipment in the fields of pipeline engineering and petrochemicals. Through special hole pattern design and rolling process, it continuously extrudes metal billets into seamless pipes, ensuring the pressure-bearing capacity and sealing performance of the pipes. In addition, copper plate rolling machines and aluminum plate rolling machines, with their excellent electrical conductivity, thermal conductivity and lightweight characteristics, have become indispensable raw material processing equipment in high-tech fields such as electronics, communications, aerospace, etc.

With the advancement of technology, rolling machine technology is constantly innovating and developing. Intelligence, automation, and high precision have become the development trends of modern rolling machines. For instance, by introducing advanced sensor technologies and data analysis systems, real-time monitoring and precise control of the rolling process can be achieved. This not only enhances production efficiency but also significantly reduces energy consumption and waste rates. At the same time, the integration of environmental protection concepts prompts the rolling machine manufacturing industry to continuously explore green and low-carbon production processes, contributing to sustainable development.

In conclusion, as a core equipment in the field of metal processing, rolling mills come in various types and are widely applied in different industries. Their diverse types and extensive application fields not only promote the transformation and upgrading of traditional manufacturing industries but also provide a solid foundation for the rapid development of emerging industries.