When the thickness of Cold Rolled Sheet And Strip is less than a certain limit (e.g. less than 1mm), hot rolling is difficult to achieve due to the difficulty of heat preservation and uniform temperature, and with the increase of width thickness ratio of steel plate, it is also very difficult to ensure good shape under tension free hot rolling conditions. Cold rolling can solve these problems. Cold rolling production can provide a large number of steel plates and strips with high precision and excellent performance. Compared with hot rolling, it has the following advantages:
1. The surface quality of the product is good, and there are no defects such as pitting, pressed iron oxide scale and so on. It can also roll out different surface finishes according to user requirements.
2. Extremely thin strip that cannot be produced by the past hot rolling method (the thinnest can reach 0,001 mm).
3. The product has accurate size, uniform thickness and straight shape.
4. Good product performance, high strength, good deep drawing performance, etc.
5. High speed rolling and full continuous rolling can be realized.
Cold Rolled Sheet And Strip has good machinability and beautiful surface. It is mostly used as external steel plate and deep drawing steel plate. Therefore, surface defects must be avoided. According to different surface finishing methods, Cold Rolled Sheet And Strip can be divided into smooth surface and rough surface. The difference of surface finishing mainly depends on the surface state of leveling roll. The surface of the steel plate is smooth (r = 8um), and the surface of the steel plate is required to have a fine roughness (r = 8um), so that the surface of the steel plate has a fine finish.
The processing of automobile fender, door, cover, hood, trailer roof, top cover, oil pan, anti-collision device and oil cover from slight deformation of door and roof to large deformation of fender and oil pan covers a wide range
Electrical appliances, refrigerators, washing machines, cleaning cars, lighting equipment, transformers, motors, magnetic cores, more use of flat plates, even if there is processing, it is extremely small
For office supplies and steel furniture, tables, chairs, cabinets, lockers, display cabinets, flat boards are often used. Good shape and small size deviation are required
Building light section steel, gas stove, kerosene stove, wing and heater need simple processing such as bending. Plane plates are often used. Even if there is processing, it is extremely small. The reflector of the furnace must also be chrome plated
Surface treatment steel plate, tinplate, galvanized plate and color coated plate are used as thick plates for surface treatment. Thinner steel plates are used. Most color coated plates use galvanized plate as substrate, and some are treated with steel plate direct coloring coating
Other toys, pots, pots and pans are multi-purpose enamel plates
The dimensional accuracy of cold rolled strip includes thickness, width and length, and its deviation is specified in the national standard. The shape is generally expressed by flatness, transverse bending and right angle, and its allowable value is also specified in the standard.
Cold rolled products are widely used and have many processing methods, from simple bending to deep drawing. According to processability, there are formability (expansibility and deep drawing) and shape type.
The so-called aging phenomenon is the phenomenon that the metal and processing properties change with the passage of time. Cold rolled steel plate has quenching aging and strain aging. Generally, when aging occurs, the hardness and tensile strength increase and the elongation decreases.
Such as enamel performance, corrosion resistance, electromagnetic performance and blanking performance.