Hot rolled steel
As the name implies, "hot rolled steel" refers to the steel rolling process by heating. Here, through the process of rolling over the high temperature of 1000 ° F, which is higher than most steel recrystallization temperature. This makes the steel easier to form and also makes the product easier to use. However, compared with its counterpart, the strength of hot rolled steel is lower than that of cold rolled steel.
Allow hot rolled steel to cool at room temperature. Unlike cold-rolled steel products, this allows the finished product to be looser than the initial material used. This also makes the finished product without the possible internal stress in the process of quenching or hardening.
Hot rolled steel is more malleable and can be cast in a variety of shapes, making it ideal for producing metal plates and structural components such as beams and rails.
Cold rolled steel
Cold rolling is the process of rolling steel at or near room temperature. Cold rolling consists of rolling flat rolled coils and sheet products. It undergoes more work than hot-rolled steel because it requires more pressure to form its shape. It has the additional effect of strengthening the material and improving the mechanical properties of finished products by machining hardening.
The cold rolling process produces more accurate dimensions than hot rolling. This is because, unlike hot rolled steel, melting does not occur during rolling.
Cold rolled steel has lower ductility than hot rolled steel, limiting it to a few simple shapes. However, due to uniform cross section and small transverse size, a series of forming operations can be used to obtain other cold rolled shapes.
It is mainly used on surfaces that need a better surface. Common applications include flat steel products for automotive parts and construction.
Cold drawn steel
Cold drawn steel is similar to cold rolled steel at room temperature. Here, the hot rolled coil or hot rolled coil is reduced to room temperature. The steel is then hammered and rolled at room temperature to ensure it passes through the die, and then pulled through the die to reshape it into a thinner shape without changing volume.
Compared with hot and cold rolled steel, cold drawn steel products can be manufactured to provide more accurate measurements and sharper angles. This is because hot-rolled steel products change during cooling.
Compared with hot-rolled steel products, cold-drawn steel also has improved yield strength and tensile strength.
Cold drawn steel also has better surface finish than hot rolled steel, making its appearance more visual aesthetic.
Cold-drawn steel products include long materials used to produce machined parts, automotive motor parts, shafts and structural units.