Introduction
Steel is a popular form of construction material all over the world. It is also essential for many industries such as automotive, aerospace, and weapon manufacturing, due to its high strength and durability. However, as steel is produced in extreme temperatures and under high pressures, it is essential to monitor the oxygen content to ensure that the desired properties are achieved in the end product. The total oxygen content in the steel is an important parameter of steel quality assessment and is a key indicator of steel production efficiency.
What is Total Oxygen Content in Steel?
Total oxygen content (TOC) in steel is a measure of the amount of oxygen present in the steel. It is generally expressed as mass percent of oxygen in steel. The amount of oxygen present in steel can be determined by gravimetric analysis and other chemical analysis techniques. In general, the total oxygen content for carbon and low alloy steels should be lower than 0.04%, while for stainless steel it should be lower than 0.03%. Oxygen present in steel can be present as either metallic oxygen, combined oxygen or free oxygen. Metallic oxygen forms an integral part of the steel matrix. On the other hand, the combined oxygen is of major importance in stainless steels, where it combines with elements such as nitrogen, sulfur, phosphorus, etc. to form compounds such as phosphates, sulphates and nitrates.
Why is Total Oxygen Content Important in Steel Production?
The total oxygen content in steel is important for a number of reasons. It is an essential factor in determining the strength and other mechanical properties of steel. As oxygen is known to have an embrittling effect on steel, higher levels of oxygen can reduce the strength of steel and hence should be kept at minimum levels. Also, oxygen can cause corrosion in steel, leading to reduced wear resistance. Oxygen in steel can also lead to increased welding defects due to increased porosity. As the total oxygen content in steel affects many of the important properties, it is essential to control the total oxygen content in the steel during production to maintain quality standards.
How to Control Total Oxygen Content in Steel?
The total oxygen content in steel is controlled through careful selection of raw materials and regular testing during the smelting process. It is also important to ensure that no oxygen is added during the production process. Oxygen can be introduced into the steel during the casting process. As such, it is important to ensure that the steel is cast from completely de-oxidized material. Suitable fluxes can also be used during the smelting process to ensure that the desired oxygen content is achieved. Another important step to control total oxygen content is to reduce the solubility of oxygen in steel. This can be done by using suitable alloying elements like chromium, manganese, nickel, and molybdenum.
Conclusion
In conclusion, the total oxygen content in steel is an important parameter in steel quality assessment and it should be kept at minimum levels. To achieve this, careful selection of raw materials and use of suitable fluxes during smelting process is essential. It is also important to reduce the solubility of oxygen in steel by adding suitable alloying elements. Proper control of total oxygen content in the steel can help improve the overall strength and mechanical properties, as well as reduce corrosion and weld defects.
