Cold-rolled plate perforated mesh and hot-rolled plate perforated mesh are two different steel rolling technologies. As the name implies, cold rolling is rolling steel at room temperature, and this kind of steel has high hardness. Hot rolling is rolling steel at high temperature.
1. Introduction to hot-rolled plate
Use continuous casting slab or initial rolling slab as raw material, heat it in a step-type heating furnace, and then enter the rough rolling mill after descaling with high-pressure water. The rough rolling material is cut into the head and tail, and then enters the finishing mill for computer-controlled rolling. After the final rolling, it is cooled by laminar flow (computer-controlled cooling rate) and coiled by the coiler to become a straight roll. The head and tail of the straight roll are often tongue-shaped and fishtail-shaped, with poor thickness and width accuracy, and the edges often have defects such as wave shape, folded edge, and tower shape. Its roll weight is heavy and the inner diameter of the steel roll is 760mm. (Generally, the pipe making industry prefers to use it.) After the straight coil is processed by the finishing line such as head cutting, tail cutting, edge cutting, and multiple straightening and flattening, it is cut into plates or re-rolled to become: hot-rolled steel plates, flat hot-rolled steel coils, longitudinally cut strips and other products. If the hot-rolled finishing coil is pickled to remove the oxide scale and oiled, it becomes a hot-rolled pickled plate coil. This product has a tendency to partially replace cold-rolled plates. It is moderately priced and is deeply loved by users.
2. Introduction to cold-rolled plates
Using hot-rolled steel coils as raw materials, cold rolling is carried out after pickling to remove the oxide scale. The finished product is hard-rolled coils. Due to the cold work hardening caused by continuous cold deformation, the strength and hardness of the hard-rolled coils increase, and the toughness and plasticity index decrease. Therefore, the stamping performance will deteriorate and 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 units are equipped with annealing lines. The weight of hard-rolled coils is generally 6~13.5 tons, and the inner diameter of the steel coil is 610mm.
Generally, cold-rolled plates and coils should be annealed continuously (CAPL unit) or bell-type furnace annealing to eliminate cold work hardening and rolling stress, and meet the mechanical performance indicators specified in the corresponding standards.
The surface quality, appearance and dimensional accuracy of cold-rolled plate punching mesh are better than those of hot-rolled plates, and its product thickness is rolled to about 0.18mm, so it is favored by the majority of users. The deep processing of products with cold-rolled steel coils as substrates has become a high value-added product. Such as electrogalvanizing, hot-dip galvanizing, fingerprint-resistant electrogalvanizing, color-coated steel coils and vibration-damping composite steel plates, PVC laminated steel plates, etc., make these products have excellent qualities such as beautiful appearance and high corrosion resistance, and have been widely used. Cold-rolled steel coils must be finished after annealing, including cutting heads, tails, trimming, leveling, flattening, re-rolling, or longitudinal shearing plates. Cold-rolled plate punching mesh is widely used in automobile manufacturing, home appliances, instrument switches, construction, office furniture and other industries.
Post time: Jun-06-2024