What is it?
Raw inputs of iron ore, coke, and lime are melted in a blast furnace resulting in molten iron. Also referred to as hot metal, this substance contains carbon and other impurities making it brittle.
Primary Steel Making
There are two primary methods; BOS and EAF. The BOS (Basic Oxygen Furnace) adds recycled scrap steel in a converter to the hot metal. The EAF (Electric Arc Furnace) method is more modern and feeds recycled steel scrap through high powered electric arcs. With temperatures up to 1650°C, the metal is melted and converted to higher quality steel.
Secondary Steel Making
This process treats the molten steel from the BOS and EAF methods to adjust the composition of the steel. The steel is adjusted by adding or removing certain elements and changing the temperature and environment.
Continuous Casting (Die Casting)
The molten steel is cast into a cooled mold. This causes the steel to solidify. Once fully cooled and solidified, the semi-finished steel slab is cut and rolled to specific lengths dependent upon application. Continuous casting is used to cast metals of uninterrupted lengths. When cast into a mold, the steel keeps travelling downward increasing in length over time.
Hot rolling is a primary forming process. In this process, the steel is cast and formed. This process eliminates cast defects and creates the desired shape and surface quality. During this process, the steel is rolled at a high temperature above the steel’s recrystallization temperature, which allow it to be shaped and formed easily.
Cold rolling is a secondary forming process for hardening the steel. In this process, the steel is passed through rollers that compress the steel to reduce thickness or create an even thickness throughout. This process is performed to steel at room temperature. As a result, it is less malleable than metal that is processed at higher temperatures.