Brief description of cold rolled coil
Cold rolled coil is made of hot rolled coil. In the cold rolled process, the hot rolled coil is wound below the recrystallization temperature, and the usually rolled steel is rolled at room temperature. High silicon steel sheet has low brittleness and low plasticity, and should be preheated to 200 degree before cold rolling. Since the cold rolled coil is not heated during the production process, there are no defects such as pitting and iron rust that are often found in hot rolling, and the surface quality and finish are good.
In addition, with high dimensional accuracy of the cold rolled product, and the performance and organization of the product can meet some special use requirements, such as electromagnetic performance, deep drawing performance and the like. Cold rolled coils are used in a wide range of applications, such as the manufacturing of automobiles, electrical products, rolling stock, aviation, precision instruments and food cans. General specifications: thickness 0.15-3mm, width 550-1530mm, coil outer diameter Φ1000-2500mm, coil inner diameter Φ410-610mm . Maximum weight: 45 tons.
Cold rolled coil production process
Cold rolled coil is made of hot rolled coil, and its production process usually goes through main processes such as raw material preparation, cold rolling, heat treatment, leveling and finishing.
Cold Rolled Coil Product Performance
The roll and tablet are almost a cut package. The chilled coil is obtained by pickling and cold rolling the hot rolled coil. It can be said that it is a kind of cold rolled coil. Cold rolled coil (annealed state): Hot rolled coil is obtained by pickling, cold rolling, bell annealing, leveling (finishing). There are 3 main differences between them:
1.In appearance, the overall refrigerated coil is a bit sloppy.
2.Cold rolled sheets such as surface quality, structure and dimensional accuracy are better than chilled coils.
3.In terms of performance, the chilled coil obtained directly after the cold rolling process of the hot rolled coil is work hardened during cold rolling, resulting in an increase in the yield strength and a part of the remaining internal tension, and the external appearance is relatively "hard". It is called a refrigerated coil.
Therefore, the yield strength: chilled coil is larger than cold rolled coil (annealed state), so cold rolled coil (annealed state) is more favorable for stamping. Generally, the default delivery state of cold rolled coils is annealed.
Chemical composition of cold rolled steel coil:
| steel grade | c | mn | Q | Yes | To the | |
|---|---|---|---|---|---|---|
| DC01 | SPCC | Less than or equal to 0,12 Spanish | Less than or equal to 0,60 Spanish | 0.045 | 0.045 | 0.020 |
| DC02 | SPCD | Less than or equal to 0,10 Spanish | Less than or equal to 0,45 Spanish | 0.035 | 0.035 | 0.020 |
| DC03 | SPCE | Less than or equal to 0,08 Spanish | Less than or equal to 0,40 Spanish | 0.030 | 0.030 | 0.020 |
| DC04 | SPCF | Less than or equal to 0,06 Spanish | Less than or equal to 0,35 Spanish | 0.025 | 0.025 | 0.015 |
Mechanical Property of Cold Rolled Steel Coil
| Brand | Yield strength RcL Mpa | Tensile strength Rm Mpa | Elongation A80mm % | Impact test (longitudinal) | |
|---|---|---|---|---|---|
| Temperature degree | AKvJ Impact Work | ||||
| SPCC | Greater than or equal to 195 | 315-430 | Greater than or equal to 33 | ||
| Question 195 | Greater than or equal to 195 | 315-430 | Greater than or equal to 33 | ||
| Q235-B | Greater than or equal to 235 | 375-500 | Greater than or equal to 25 | 20 | Greater than or equal to 2 |
Available Steel Grades and Application:
| Material category | Baosteel Enterprise Standard | National standard | Japanese industrial standard | German industry standard | European standard | American Test Materials Standards Society | Observations | |
|---|---|---|---|---|---|---|---|---|
| Brand | Brand | Brand | Brand | Brand | Brand | |||
| Low Carbon and Ultra Low Carbon Cold Rolled Steel Sheets and Strips | Commercial Grade (CQ) | SPCCST12 (German standard) | Q19510-P10-S08-P08-S08AI-P08AI-S | SPCC | ST12 | FeP01 | ASTMA366/A366M-96 (replaced by ASTM A366/A366M-97) | Q195 in 1.1GB11253-89 is a common carbon structural steel. 2.2 Such steel can be used for the production of automobile parts, furniture shells, barrel steel furniture and other simple forming, bending or welding products. |
| Stamping level (DQ) | SPCDST13 | 10-Z08-Z08AI-Z | SPCD | USt13RRSt13 | FeP03 | ASTMA619/A619M-96 (obsolete after 1997) | It can produce parts for more complex stamping and deformation processing, such as automobile doors, windows, fenders and engine casings. | |
| Deep drawing (DDQ) | SPCE-FSPCE-HFSPCE-ZFST14-FST14-HFST14-ZFST14-T | 08AI-F08AI-HF08AI-ZF | SPCE | ST14 | FeP04 | ASTMA620/A620M-96 (replaced by ASTM A620/A620M-97) | 1.1. It can produce deep drawing parts such as automobile front lights, mailboxes, windows, etc., as well as complex and severely deformed parts. 2.2.Q/BQB403-99 The newly added ST14-T is exclusive to Shanghai Volkswagen. | |
| Deep Drilling (SDDQ) | ST15 | FeP05 | It can produce very complicated parts, such as car mailboxes, headlights and complex car floors. | |||||
| Ultra deep drawing (EDDQ) | ST16BSC2 (BIF2) BSC3 (BIF3) | FeP06 | 1.1. This type is ultra deep with no gaps. 2.2. 1F18 in the area agent FeP06 SEW095 from EN 10130-91. |
Cold Rolled Coil Grade
1. Chinese brand No. Q195, Q215, Q235, Q275——Q—the code of the yield point (limit) of ordinary carbon structural steel, which is the case of the first Chinese phonetic alphabet of "Qu"; 195, 215, 235, 255, 275 - respectively represent the value of its yield point (limit), the unit: MPa MPa (N/mm2); Due to the comprehensive mechanical properties of strength, plasticity, toughness and weldability of Q235 steel in ordinary carbon structural steel Most, it can better meet the general requirements of use, so the scope of application is very wide.
2. Japanese brand SPCC - Steel, P-Plate, C-cold, quarter C-common.
3, Germany grade ST12 - ST-steel (steel), class 12 cold rolled steel sheet.
Application of cold rolled steel sheet:
Cold rolled coil has good performance, that is, through cold rolling, cold rolled strip and steel sheet can be obtained with thinner thickness and higher precision, with high straightness, high surface smoothness , clean and shiny surface of cold rolled sheet metal and easy coating. Plating processing, variety, wide use and characteristics of high stamping performance and non-aging, low yield point, so cold rolled sheet has a wide range of uses, mainly used in automobiles, iron drums printed materials, construction, building materials, bicycles, etc. The industry is also the best choice for the production of organic coated steel sheets.
