Improvement of RH refining technology for production of ultra-low carbon steel at kwangyang works, posco

摘要

Experimental and theoretical studies were carried out to understand the effects of operational conditions(flow rate of lift gas, vacuum degree, snorkel diameter and oxygen top blowing) on the decarburisation characteristics in 250ton RH vacuum deagsser. From the tests for complete mixing time measurement with Cu tracer, increase in flow rate of lift gas or higher vacuum degree was effective to reduce complete mixing time. However, the effect of snorkel inner diameter was not observed. Decarburisation characteristics for refining ultra-low carbon steel were enhanced by the increase of snorkel diameter. Lift gas injection through directional type porous plugs increased apparent decarburisation rate(Kc) and reduced decarburisation time while producing ultra-low carbon steel.