Hot-rolled coils can also be called hot coils, which are strips made of slabs (mainly continuous casting slabs) and heated by rough rolling units and finishing rolling units, generally including medium-thick and wide steel strips, hot-rolled Rolling thin wide steel strip and hot rolled sheet. The hot steel strip coming out of the last rolling stand of finishing rolling is cooled to the set temperature by laminar flow, and rolled into a steel strip coil by a coiler. Common materials are Q235B, Q345B, SPHC, 510L, Q345A, Q345E, etc., mainly used in construction, machinery, pressure vessels, bridges and other industries
Classification of hot rolled coils:
Hot-rolled coils can be divided into: straight hair coils and finishing coils (divided coils, flat coils, slit coils);
According to different materials and properties, it can be divided into: ordinary carbon structural steel, low alloy steel, alloy steel;
According to different uses, it can be divided into: cold forming steel, structural steel, automobile structural steel, corrosion-resistant structural steel, mechanical structural steel, welded gas cylinder and pressure vessel steel, pipeline steel, etc.
The properties of carbon steel are high hardness, strength, wear resistance and anti-corrosion.
Carbon steel is an alloy with carbon and iron, with carbon content up to 2.1% by weight. The increase in the carbon percentage will raise steel’s hardness and strength, but it will be less ductile. Carbon steel has good properties in hardness and strength, and it is less expensive than other steels.
Chemical composition and Mechanical property | |||||||||
Standard | Grade | C max | Mn max | Si max | P | S | Yield strength MIN | Tensile strength MIN | Elongation% |
ASTM A572M | 50 | 0.23 | 1.60 | 0.50 | 0.04 | 0.05 | 345 | 380 | 21 |
GB/T8162 | Q345B | 0.22 | 1.0-1.60 | 0.40 | 0.04 | 0.03 | 345 | 375 | 21-26 |
ASTM A36 | A36 | 0.24 | - | 0.40 | 0.045 | 0.030 | 250 | 400-520 | 26 |
Hot Rolled Steel Plate Steel Manufacturing Processes
Hot rolled material is annealing in cold rolled annealing furnace and after pickling in acid.
All mill rolls are grinded on precision grinding machine with proper chamfering after first shift operation.
All sheets are pickled in different tanks and sheets are dried on brush roll machine before dispatch.
These sheets are again annealing then sent to straighten machine for straightening and pickling in acid and send for packing according to size and quality.
Inspection is done at various stages. By experience staff keeping proper control overall internal process via rolling, annealing, pickling, treatment of waste etc.