Argon Rinsing of Steels Oct26

Argon Rinsing of Steels...

Argon Rinsing of Steels Gas rinsing process is a method where rinsing of liquid steel in the teeming ladle is carried out through injection of inert gas into the steel bath. Argon (Ar) gas is preferred for rinsing since it is not only inert in nature but its solubility in steel is also very low. Rinsing results from the expansion of gas due to heating and decrease in pressure as the gas rises. The Ar rinsing of liquid steel is carried out for obtaining homogenous temperature, composition, and promotion of slag metal refining reaction.  The Ar rinsing of liquid steel is reported to be an excellent process for floatation and separation of non-metallic inclusions. The liquid steel after tapping is stratified in the teeming ladle due to the additions of the ferro alloys and the carburizer in the teeming ladle at the time of tapping of the steel. This stratified steel is agitated by purging of Ar gas in the Ar rinsing station. Ar gas purging through the liquid steel bath help generate enough bath turbulence to effect rapid thermal homogenization. Stirring with Ar also enhances mixing rate for chemical additions. Different variables for argon rinsing include gas purging rate, amount of liquid steel (heat size), amount of superheat available in the liquid steel, amount of carry over slag, amount of synthetic slag or ladle covering compound added, amount of mixing needed for chemical additions. Experienced operators and metallurgists recognize the importance of accurate and consistent Ar gas rinsing in the teeming ladle. Clean steel and good castability in the continuous casting machine (CCM) depend on a consistent and gentle rinse stir. A good Ar rinsing control system at the Ar rinsing station facilitates reproducible and accurate argon rinsing rates and durations. Ar gas can...