1. Carbon Content
The carbon content of hot-rolled steel can be slightly higher than that of cold-rolled steel. The density is the same when there are little differences in the components.
2.Density
The density and composition of hot rolled steel can be checked through looking for various steel to find the specific one. Cold rolled steel has high hardness and relatively has difficult for processing, but it is not easy to deform and has high strength.
3. Production Process
The production process of hot-rolled steel and cold-rolled steel is different. Hot rolling steel is rolled at high temperature and cold rolling steel is processed from hot rolled steel at normal temperature. Generally speaking, cold rolled steel has better strength and hot rolled steel has better ductility.
What Are The Differences Between Hot Rolled Steel And Cold Rolled Steel
1.The Surface
The cold steel plate is cold rolled and the surface has no oxide scale with good quality. The hot steel plate uses hot rolled processing technique with oxide scale on the surface.
2. Toughness & Stretchability
Hot rolled steel has poor toughness and the price is low, while cold rolled steel has good stretchability and toughness, but the price is more expensive
3.Mechanical Properties
The cold rolled steel has much better mechanical properties than hot rolled steel.
4. Formability
Since the surface of cold rolled steel is better than hot rolled one, the forming effect also better than that of hot rolled steel.
5. Torsion resistance
Hot rolled steel has higher free torsional stiffness than cold-rolled steel, so the torsional properties of hot-rolled steel are better.
6. Smoothness
The smoothness of cold rolled steel sheet is better than that of hot rolled sheet.
Overall, cold rolled steel has better performance than hot rolled steel, but cold rolling process will cost more and the cold rolled steel has higher price than that of hot rolled one. People should choose the suitable one according to their needs. No matter what types of the rolling is, the mill rolling process plays an important role in steel making and mill roll is essential for the perfect dimensions.
Maybe different people have different views on hot rolled steel and cold rolled steel. Hope the simplified explanation will help people learn more about the two types of steel or steel plate.
Hot rolling and cold rolling are the two main processes for the most steel or steel plate making, which have great influences on the structure and properties of the steel. A better rolling mill roll will bring more superior quality steel. Which one is better between the hot rolled steel and cold rolled steel?
Some information about the hot rolled steel and cold rolled steel is introduced.
Hot Rolled Steel
Definition
Hot rolled steel is the finished product through directly processed on the steel mold in the steel furnace with exceptionally high temperatures, rolling with the hot mill roller which can make sure the dimensions of the steel sheet according to the requirements., then coiled and cooling. The main steel rolling type is hot rolling.
Advantages
Compact the steel structure and improve the mechanical properties.
Disadvantages
1.After hot rolling, delamination occurs, when the non-metallic inclusions in the steel are pressed into thin sheet. Delamination greatly deteriorates the tensile properties of the steel.
2. Residual Stress caused by uneven cooling. Residual stress is internal self-phase equilibrium stress without external force. Hot rolled steel may have negative effects on deformation, stability, fatigue resistance, etc.
Cold Rolled Steel
Definition
The cold rolled steel bar is obtained by cold working of the hot-rolled steel, such as cold drawing and stretching at a normal temperature. Cold rolling is often used for the production of small sections and steel sheets.
Advantages
Cold rolled steel bar has fast forming speed and high output. It can be made into a variety of cross-sectional forms to meet the requirements of the different use conditions. Cold rolling mill can make the steel have a large plastic deformation.
Disadvantages
Torsion is prone to occur under bending. Bending and torsional buckling is easy to occur under compression. So the torsional performance of cold-rolled steel is poor, and the ability to withstand concentrated loads is weak.
Pipe and Round Bar Straightening Machine
The pipe straightening machine is possible to straighten pipes and rods of Φ6-Φ30mm and use different types of straighteners for different specifications.
Specification
Straightening pipe diameter circumference (mm): Φ5~Φ20
Straightening pipe wall thickness (mm):0.5~4
Straightening tube yield strength (N/mm2): ≤392
Straightening speed (m/min): 32.5
Straightening roller angle adjustment range: 30°~33°
Straightening roller throat diameter (mm):Φ75
Straightening roller body length (mm): 100
Straightening roller distance (mm): 190
Allowable bending before adjustment (mm/m):≤30
One-time bending (mm/m): ≤1
Motor power (kW):1.5x2
Machine Dimensions (mm):1275x890x1405
Machine weight (Kg):1050
Straightening roller configuration: 2-2-2-2-2
Scrap Rebar Straightening Machine
Specification
Straightening range:Φ5-12mm
Straightening speed:14m/min
Motor power: 5.5kw、4kw
Feature
Due to rail guides, the steel bar can be moved in and out more smoothly anti-smash hook design is adopted. The dead bend can also pass through the alloy steel cutting device. The work lifespan is long.
The TINVO scrap rebar straightening machine is to change the shape of the steel bar into a straight strip that can be reused, by means of passing the old rebar and the waste round steel through several straightening rolls.
R4-R5 Continuous Casting Machine
R4-R5 continuous casting machine is a single unit single strand small continuous casting machine. It has a production capacity of 5-12 tons per hour. It's suitable for electric furnaces of more than 1 ton, multi-furnace continuous casting and intermittent small batch casting. The user who has a lower factory building and no crane can install the continuous casting machine underground, which is convenient for manual bag pouring and electric furnace pouring.R6 Multi-Strand Continuous Casting Machine
Technical characteristics
1. Simplified slab guiding device, low cost and easy maintenance
2. Five-roll four-drive straightening machine with a large pulling force
3. The auxiliary straightening machine can perform secondary straightening of the slab in the accident state.
4. Special flying shears can be quickly and accurately cut to length
5. The surface grinding rate is less than 5%
Process parameters
Model: Full arc continuous square billet continuous casting machine
Number of strands: 1, 2, 3, 4, 5, 6
Casting machine radius: 6, 8, 10m
Billet specifications: 80*80, 90*90, 100*100, 120*120, 150*150, 180*180, 200*200, 240*240mm
Rectangular billet: (120 ~ 200) (240 ~ 600)mm
Working speed: 0.6~1.2 m/min
Annual output: 10 to 150,000 tons /strand
Spill rate: ≤0.1%
Continuous pouring time: ≥8h
Φ80-150 Round Billet Continuous Casting Machine
The Φ80-150 round billet continuous casting machine refers to a machine that mainly produces tube blanks for seamless steel pipes and it adopts continuous cast steel iron-making technology. The continuous casting round billet is mainly used to produce seamless steel tubes of different calibers. When the round billet is passed through, the billet is required to have no cracks of surface and internal, and it is necessary to prevent the inner surface defects of the steel pipe which caused by large particle inclusions.
R8-R12 Rectangular Billet Continuous Casting Machine
The R8-R12 rectangular billet continuous casting machine is also included in the billet continuous casting machine, which is divided according to the size and shape of the cast section cast by continuous casting machine.
For more detail professional knowledge about CCM, you can visit introduction page of the TINVO steel making machinery.
1.Water-cooled Furnace Cover
The water-cooled furnace cover is the upper part of the arc furnace body, which can be moved. It is equipped with a discharge entry and a flue exit. It can be manufactured separately.
2.Water-cooled Furnace Wall
The water-cooled furnace wall is located in the middle of the furnace body. It consists of a water-cooled frame and multiple water-cooled plates. Due to transportation reasons, it can be manufactured separately according to the specific size. It is welded and assembled in the installation site.
3.Bottom Ring of The Furnce Cover
The bottom ring of the furnace cover is located at the lower end of the furnace body and plays a role in protecting the furnace wall.
4.Flue Elbow of Water-Cooled Furnace Cover
The water-cooled furnace cover flue elbow is a transitional connection for exhausting dust from steelmaking.
5.Eccentric Zone Water Cooling Plate
The eccentric zone water cooling plate is used for water cooling in the eccentric zone of the furnace door frame.
6.Ladle
The ladle is a container used for the transfer or refining of molten steel.
All above spare parts for steel making plant are supplied by TINVO and you can inquire the details through page of Contact TINVO Rolling Mill or the Email : inquiry@hrbtinvo.com.