Hot-rolled stainless steel coil refers to stainless steel coil obtained by hot rolling process. Hot rolling process is the process of metal processing at a higher temperature, usually at a temperature above 1000°C. In this process, the metal is heated, rolled and other treatments to form a steel coil of a certain thickness and width in the hot rolling mill. Hot-rolled stainless steel coils are usually rough and suitable for areas that do not require high surface quality.
What Is Hot Rolling?
Hot rolling refers to the deformation of metal materials by pressure above the metal recrystallization temperature, usually at a high temperature of 1000°C to 1250°C. The hot rolling process can significantly reduce the thickness of the metal, making it more uniform and flat, while improving the ductility of the metal.
For stainless steel, hot rolling is to heat the steel billet of components such as chromium-nickel alloy to a certain temperature and then gradually roll it into a thin coil through multiple rolling processes. Stainless steel hot-rolled coils are characterized by low cost and high production efficiency, especially suitable for mass production.
Technical Features Of Hot-Rolled Stainless Steel Coils:
Thickness And Width Control:
The final thickness and width of the stainless steel coil can be effectively controlled by adjusting the rolling speed, rolling pressure and heating temperature. Modern hot rolling technology has been able to control the thickness of ss coils between 0.1 mm and 100 mm, and the width ranges from tens of millimeters to thousands of millimeters.
Physical And Mechanical Properties:
The mechanical properties of hot-rolled stainless steel coils are closely related to factors such as the size of the grains and the cooling rate during its production process. Due to the high temperature treatment during hot rolling, hot-rolled stainless steel usually has good ductility and toughness, and is suitable for deep processing or secondary processing.
However, since high-temperature rolling causes the coarsening of the material grains, the strength and hardness of hot-rolled stainless steel are usually not as good as those of cold-rolled stainless steel. This makes hot-rolled stainless steel more suitable for some applications with relatively low strength requirements but high toughness and impact resistance requirements.
Surface Quality:
The surface of hot-rolled stainless steel coils is relatively rough, and scale (i.e., the substance after oxidation of the metal surface) usually appears. This may be due to contact with air during hot rolling. Therefore, hot-rolled stainless steel coils usually need to undergo post-treatment processes such as pickling to remove surface oxides and improve surface quality.
Classification Of Surface Treatment Of Stainless Steel Coils
The surface treatment method of hot-rolled stainless steel coils directly affects its appearance and performance. According to different surface treatment methods, it can be divided into the following types:
Hot-rolled surface (HR)
After hot rolling, the surface of hot-rolled stainless steel coils is generally rough with obvious oxide scale. This surface is usually treated with post-treatment processes such as pickling and polishing to remove the oxide scale and improve the surface quality.
Pickled surface (2B)
The pickled surface is the surface obtained after the stainless steel is treated with the pickling process, and the surface is usually smoother. The pickling process removes the oxides generated during the hot rolling process and improves the corrosion resistance of the surface.
Bright surface (BA)
Bright surface (BA, Bright Annealed) is the surface of stainless steel after annealing and surface brightening. It has a highly smooth and bright surface.
Mirror surface (Mirror)
The mirror surface is a stainless steel coil that has been precisely polished and has a mirror luster.
Brushed surface (No. 4)
The brushed surface is obtained by mechanical grinding and has a certain texture effect.
Application Areas Of Hot-Rolled Stainless Steel Coils:
- Construction and decoration industry: hot-rolled stainless steel coils are used for building facades, interior decoration, door and window frames, etc.
- Machinery manufacturing: hot-rolled stainless steel coils are often used to manufacture mechanical equipment, pressure vessels, pipelines and other parts.
- Automobile industry: hot-rolled stainless steel coils are widely used in automobile shells, automobile parts, exhaust pipes and other fields.
- Food industry: hot-rolled stainless steel coils are widely used in the manufacture of food processing equipment and kitchen utensils.
- Chemical engineering and energy industry: hot-rolled stainless steel coils are often used to make reactors, pressure vessels, pipelines and storage tanks, etc.
Difference Between Hot-Rolled Stainless Steel Coil And Cold-Rolled Stainless Steel Coil
|
Comparison Dimension |
Hot-Rolled Stainless Steel Coil |
Cold-Rolled Stainless Steel Coil |
|
Manufacturing Temperature |
Processed at high temperatures |
Processed at room temperature |
|
Surface Finish |
Rougher surface finish |
Smoother surface finish |
|
Material Thickness |
Thicker, generally over 3mm |
Thinner, suitable for thin sheet needs |
|
Mechanical Properties |
Good ductility, suitable for large parts |
High precision, suitable for small, precise parts |
|
Application Fields |
Construction, shipbuilding, heavy machinery |
Home appliances, electronics, precision manufacturing |
Hot-rolled stainless steel coils are widely used in heavy industry and construction due to their excellent high-temperature strength and good ductility. Although the surface quality is slightly worse than that of cold-rolled products, this is due to the strength and toughness of cold-rolled products. When choosing stainless steel coils, we can choose the right product according to our own use.
