• Patel, Deepak

Abstract

Non-metallic inclusions are a major issue during the production clean steels, as they influence the microstructure and structural properties effectively. They are often considered as harmful to the final product quality and to the steel processing productivity; therefore many industrial efforts are directed towards improving inclusion removal. Another way is to use non-metallic inclusions to produce steels with enhanced properties. In both cases, the key issue is to control the characteristics of the inclusion population in the liquid steel, such as quantity/limit, composition, physical appearance or morphology, shape, size and distribution. The application of new secondary refining techniques and non-metallic inclusion reduction techniques in steel production processes has greatly reduced the size and amount of nonmetallic inclusions remaining in molten steels and steel products due to which inspection of inclusions is very difficult. The influences of inclusions on the properties of steels are discussed. As inclusions have influence on several properties of steel, such as formability, toughness, and machinability and corrosion resistance. In general, the less severe the inclusions, the higher quality of steel. This is the reason for, analysing and assessment of non-metallic inclusions is important for quality control. The main part of this work has been a literature survey, reviewing the main methods used for the characterization of inclusions in clean steels, experimental reports for information on how steel cleanness is evaluated today, and how the steel cleanness is related to the performance of clean steels as a product.

Topics

• impedance spectroscopy
• microstructure
• morphology
• corrosion
• inclusion
• laser emission spectroscopy
• steel