Hot Rolled Steel
General information on hot rolled steel
Hot rolled steel products are rolled into shape at an ambient temperature of approximately 1700°F. Method and rolling temperature (hot or cold rolled) are typically chosen according to the end product specifications required. Depending on its chemical composition, hot rolled steel products can be manufactured with different degrees of formability, hardness, a resistance to corrosion and heat or a special drawing. Hot rolled steel (steel hr) is therefore known to be very versatile. At first glance hot rolled sheet metals can be identified by their thickness. If a thinner, stronger material with tighter tolerances is required, subsequent cold rolling is advisable to further reduce material thickness.
Explanation of the hot rolling process
When hot rolling, slabs, blooms or billets (also known as primary steel products) are passed through a rolling mill at a very high temperature. The heat helps to soften material thus enabling easy manipulation (rolling) into shape. While steel is heated multiple times during cold rolling processes, when hot rolling material is only heated once. Hot rolled steel products are therefore quicker and cheaper to manufacture in bulk. Subjecting steel to such high temperatures has one drawback: As the material cools down it is prone to shrinking. For that reason it is almost impossible to manufacture hot rolled sheets and plates according to exact measurements. They nonetheless find application in industries where measurement tolerances are more flexible. If tighter tolerances are required it is advisable to select a cold reduced product instead.
Which sectors utilise hot rolled steel?
As previously mentioned tolerances in dimensions for hot rolled sheet metal lies between 2 and 5 percent. Hence, hot rolled products tend to be more popular in heavy application sectors including transportation (automotive and rail tracks), agricultural equipment, energy, marine, defence but also construction and machinery to name only a few. Due to their versatile nature and cost efficiency hot rolled steel products are popular throughout a wide variety of different industries and sectors.