Abstract: The effect of ternary slag (/% : 65CaF₂ , 25Al₂O₃, 5SiO₂ ) , quaternary slag (/% : 55CaF₂ , 20Al₂0₃, 20SiO₂, 5CaO) and quinary slag (/% : 45CaF₂,20Al₂O₃,25SiO₂,5CaO, 5MgO) on metallurgical quality of electro-slag ingot of S-Pb-Te free cutting stainless steel (/% : 19 -21Cr, 1.5 -2. 5Mo, 0. 1 -0. 3Pb,0. 25 -0. 40S,0. 03 -0. 10Te) has been tested and studied by 500 kg shielding atmosphere electro-slag remelting ( ESR) furnace. Results show that the yield of S in steel remelting by quaternary slag and quinary slag is higher than that by ternary slag ； the yield of Pb remelting by ternary slag is relative higher； the yield of Te remelting by three kind of slag series is no-obvious difference； with SiO₂ content in steel remelting by quinary slag is 25. 0% the deviation of S, Pb and Te content in S-Pb-Te free cutting stainless steel ESR ingot from top to bottom is minimum, that are respectively AS 0. 03% , APb 0. 02% and ATe 0. 028% , and the surface quality of electro-slag ingot is best.

Key words: Electro-Slag Remelting, , Acid Slag, SiO₂ Content, S-Pb-Te Free Cutting Stainless Steel, Metallurgical Quality