Steel is one of the most important materials currently used in industry. It is especially valued for its excellent properties. In addition, we must not forget that steel is relatively easy to produce, and the raw materials needed for this process are widely available.
Types of Steel
Depending on what we are constructing, the appropriate type of steel should be used. This is very important because only then will the structure be durable. Furthermore, steel behaves differently depending on the conditions. For example, when building ships, we choose corrosion-resistant steel.
On the other hand, if the structure must resist brittle fracture, we should use special quality steel instead of basic steel. Quality steel is definitely a material for special tasks.
Steel is generally classified based on its chemical composition into:
-alloy steel,
-non-alloy steel
According to the PN-EN 10020:1996 standard, there is a table that specifies the element content limits for a given steel. If the element content is below these limits, it is classified as non-alloy steel. If it exceeds these limits, it is considered alloy steel. Engineers must distinguish between these types, as the presence of elements significantly affects strength.
Both alloy and non-alloy steels can be further divided into basic and quality steels. Quality steels, used for special purposes, are increasingly popular. Interestingly, quality steels are also divided into:
-non-alloy quality steels
-alloy quality steels
Non-alloy quality steels have undefined properties after heat treatment and unspecified metallurgical purity. Metallurgical purity refers to the degree of non-metallic inclusions. These steels are used in flat products for cold forming, hot-dip galvanized products, pressure vessels, gas cylinders, and ships. They are also used as rail, spring, and free-cutting steels for reinforcing concrete, wire drawing, and cold upsetting.
Alloy quality steels differ by having a higher content of alloying elements. According to PN-EN 10020:1996, their content exceeds defined norms. They include:
- structural steels, especially fine-grained weldable steels
- electrical steels with silicon or silicon and aluminum
- steels used in rails, sheet piles, and mining supports
- steels for hot-rolled and cold-rolled flat products for cold forming
- copper-alloyed steels.
Steel Rolling – Types of Processing
As previously mentioned, quality steel undergoes various processes, including rolling. This process shapes the material between rotating disks, rollers, or other moving tools. It is a type of metal plastic forming, done on machines called rolling mills. These are specialized high-quality devices powered by a single main drive.
Rolling mills are categorized as:
- cold rolling and hot rolling mills
- bending and drawing mills
- straighteners and scale breakers
- cooling units
- special mills for pipes, sheets, and profiles.