The Approach of Low Desulfurization of Steel
The composition of steel usually includes an element called sulfur, which can do a great influence on the structure and performance of the steel. To control the sulfur content of steel is the first step for the stability of steel quality and performance. This way, sulfur control and desulfurization process becomes the important part of steel production. After the steel composition meets the demands, sulfur can be removed from the molten steel. In this article, the introduction and approach to low desulfurization of steel will be discussed.
Introduction to Low Desulfurization of Steel
Relatively low sulfur level can be highly beneficial prior to further processing. The sulfur content of steel is usually limited to less than 0.04 % by mass. Though, the contents may be higher or lower depending on the steel application. For the special application, the sulfur content needs to be further reduced. Thus the desulfurization techniques and process become quite important.
The steel desulfurization includes two main techniques: Physical and chemical techniques. The physical techniques, such as inert gas stirring and vacuumization, are used to selectively remove the sulfur-containing elements by converting them into powder or gasforms. Chemical techniques, such as oxygen blowing and vacuum oxygen decarburization, take advantage of chemical reaction to reduce the sulfur content in the steel.
Approach to Low Desulfurization of Steel
For low desulfurization process, two main approachs: Physical and chemical techniques can be used.
Physical Techniques
In physical technique, Argon blowing is a widely used approach. By using argon blowing, the sulfur component can be converted from liquid and gaseous forms that can be separated from the steel. This technique is effective for sulfur contents up to 0.05 %. Other physical techniques include oxy-hydrogen desulfurization, nitrogen-hydrogen desulfurization and vacuumization.
Chemical Techniques
Chemical technique take advantage of chemical reaction to reduce the sulfur content in the steel. Oxygen blowing is a widely used approach. By using oxygen blowing, the sulfur component can react with the oxygen to become gaseous sulfur dioxide and the sulfur dioxide can be removed from steel. This technique is more effective than physical approaches, and can reduce the sulfur content up to 0.001 %. Other chemical schemes include vacuum oxygen decarburization and calcium treatment.
Conclusion
With development of steel industry, the desulfurization process also plays an increasingly important role in controlling the sulfur content of steel. There are two main approaches currently used for low desulfurization of steel, such as physical and chemical techniques. By using physical or chemical techniques, the low desulfurization could be achieved successfully.
