Behavior of Alloying Elements during Drawing-Ingot-Type Electroslag Remelting of Stainless Steel Containing Titanium

摘要

Experimental and theoretical studies have been carried out to study the effects of slag and metal electrode compositions on alloying elements in ingot during Drawing-Ingot-Type electroslag remelting (ESR) with a focus of developing a numerical model to control titanium and aluminum. The mass transfer model based on the penetration and film theories is established to analyze the Fe+FeO, Ti+TiO_(2), Al+Al_(2)O_(3) and Si+SiO_(2) concentration changes along the height of ESR ingot. The results show that the combination of slag containing high CaO content, extra TiO_(2) incessantly added into slag in the first slag-temperature-rising period, and extra SiO_(2) incessantly added into slag during the whole ESR process is suitable for Drawing-Ingot-Type ESR of AISI321 steel. The mass transfer model shows that the remelting rate has little effect on the change of silicon, aluminum and titanium content in ingot, while the titanium content in electrode has significant effect on silicon, aluminum and titanium content in ingot. Since the titanium in AISI321 stainless steel ingot ranges from 0.4% to 0.8%, the titanium in electrode needs to be larger than 0.9% because of the titanium’s reaction with silica. In addition, the alloying element content in ingot under different remelting rate, electrode and slag composition are estimated based on the mass transfer model.