Alkaline Open Hearth Steelmaking
Open hearth steel making is a process which used to be the main form of smelting steel since the industrial revolution of the 19th century. This process involved using a large, angled, open-topped structure heated by gas or coal. The name “open hearth” comes from the fact that the heat inside the structure came from an open flame, not from sealed burners. Inside this furnace, scrap steel and iron are melted and mixed with other ingredients, including fluxes and scraped to form the desired steel. Alkaline open hearth steel making entails three steps which are preheating of the steel material, melting and refining the steel, and finally pouring it into molds.
The preheating of the steel material is done in an atmosphere controlled by the equipment operator. The atmosphere consists of natural gas, carbon dioxide, and other gases which are used to create a neutral environment. This helps to prevent oxidation of the steel material during the preheating process. The preheating is done in the presence of a powerful alkaline which helps to reduce the amount of oxidation that takes place.
Once the steel material has been preheated, it is melted in the open hearth furnace. The heat from the furnace is evenly applied to the entire surface of the furnace. Molten iron, which is already present in the furnace, is mixed with the preheated steel material. This molten iron is heated to a temperature of about 1600 degrees Celsius. At this temperature, the slag, which is a combination of impurities in the steel, is melted and removed from the furnace. This helps reduce the possibility of contamination in the steel material.
The next step of the process is the refining phase. During this phase, additives are used to alter the composition of the steel material. These additives can be anything from elements like magnesium and aluminum, which are added to create specific properties in the steel material, to oxygen and nitrogen which help to remove impurities from the steel material. The temperature of the material is also closely monitored during the refining process in order to ensure optimal results. Once the desired composition is achieved, the molten steel material is poured into molds and cooled completely.
Once the steel material has cooled and solidified, it can be further manipulated for use in various applications. This includes extrusion, forging, press forming, painting, and more. Alkaline open hearth steel making is a complex process that requires knowledge and expertise in order to achieve optimal results. It is not something that can be done by just about anyone and requires a certain amount of skill.
Open hearth steel making has been used for decades and is still popular today, in part because it is able to produce high-quality steel products that can meet stringent industry standards. The process is also relatively inexpensive, making it a cost-effective way to produce steel. Although the process can be a bit time consuming, the end result is often superior to comparable methods. For these reasons, alkaline open hearth steel making is likely to remain an important part of the steel industry for many years to come.
