Cold Rolled Steel Coil
The difference between chilled coil and cold rolled coil:
Chilled coils are hot-rolled coils that are pickled and cold-rolled. It can be said to be a kind of cold rolled coil.
Cold-rolled coils (annealed state): hot-rolled coils obtained by pickling, cold rolling, bell annealing, tempering, and (finishing).
There are three main differences between the two:
1. In appearance, generally chilled coils are a bit black.
2. The surface quality, structure, and dimensional accuracy of cold-rolled sheets are better than chilled coiled sheets.
3. In terms of performance, because the chilled coil directly obtained by the hot-rolled coil through the cold rolling process undergoes work hardening during cold rolling, resulting in an increase in yield strength and residual internal stress, the external performance is relatively "hard". It is called chilled coil.
Therefore, the yield strength: the chilled coil is larger than the cold-rolled coil (annealed state), which makes the cold-rolled coil (annealed state) more conducive to stamping.
Generally, the default delivery state of cold-rolled coils is annealed.
Mechanical properties of cold rolled coil:
Cold-rolled coil grade, supply standard, product size and use
Classification of cold-rolled steel sheets:
Cold-rolled ordinary thin steel plate: cold-rolled from ordinary carbon structural steel or low-alloy structural steel. The surface quality of cold rolled sheet is better. Has good stamping properties. It is required to ensure that the cold bending and cup tests are qualified, and it is often used in industries such as automobiles and raw materials for coated sheets.
Cold-rolled high-quality thin steel plate: mainly includes various high-quality steel cold-rolled thin plates, the most commonly used is carbon structural steel plate, especially cold-rolled thin steel plate for deep drawing, which is cold-rolled thin plate made of low-carbon high-quality steel 08Al. The quality is divided into three groups; Ⅰ, Ⅱ, Ⅲ, which represent special high-grade, high-grade, and higher finishing surfaces, respectively, and are divided into ZF, HF, and F grades according to the drawing level (representing the most complicated and very high-end surface for punching and drawing). Complicated and complex parts). According to the allowable deviation of steel plate thickness, it is divided into two levels of precision, A and B, and is widely used in the automobile and tractor industry.
Cold-rolled steel plate: smooth surface, excellent processing, used in home appliances such as automobiles, refrigerators, washing machines, industrial equipment, and various building materials. With the development of the economy, cold-rolled steel sheets have been called necessary materials in modern society. Classification of cold-rolled products: hot-rolled pickling, hard-rolled coil, ordinary cold-rolled, galvanized (electro-galvanized, anti-fingerprint, hot-dip galvanized), galvanized, electro-tinned, color-coated, electrical steel (silicon steel sheet) wait.
Cold-rolled hard coils: Continuous rolling of hot-rolled pickled coils at room temperature.
Product features: Because it has not been annealed, its hardness is very high (HRB is greater than 90), and its machinability is extremely poor. It can only perform simple directional bending less than 90 degrees (perpendicular to the coiling direction).
Cold Rolled Coil Application
It has a wide range of uses, such as automobile manufacturing, electrical products, rolling stock, aviation, precision instruments, food cans, etc. Cold-rolled thin steel plate is the abbreviation of ordinary carbon structural steel cold-rolled plate, also known as cold-rolled plate, commonly known as cold-rolled plate, sometimes mistakenly written as cold-rolled plate. The cold plate is a hot-rolled strip of ordinary carbon structural steel, which is further cold-rolled into a steel plate with a thickness of less than 4mm. Due to rolling at room temperature, no iron oxide scale is produced. Therefore, the cold plate has good surface quality and high dimensional accuracy. With the addition of annealing treatment, its mechanical properties and process properties are superior to hot-rolled thin steel plates. In many fields, especially In the field of home appliance manufacturing, it has gradually replaced hot-rolled steel sheets.
Applicable grades: Q195, Q215, Q235, Q275; SPCC (Japanese grade); ST12 (German grade)