Medium carbon sulfur free-cutting steel 1141 (%:0.37～0.45C

1.20~1.65Mn

0.06～0.12S) and steel 1144 (%:0.40~0.48C

1.35~1.65Mn

0.24~0.33S) are melted by 65 t Consteel EAF-LF(VD)-(150～200) mm ×(150～200) mm CC flow sheet.With feeding Al wire during refining to control [Al

]

0.02%~0.05%

end-refining-slag basicity (CaO/SiO

2

) 2.62~3.02 to keep sulfide capacity in end refining up to saturation state

and blowing argon 200~250 L/min

≥ 15 min during VD process

the [S

]

of steel 1141 before and after VD is respectively 0.11%~0.12% and 0.10%～0.12%

and the [S

]

of steel 1144 before and after VD is respectively 0.30%～0.33% and 0.29%~0.30%

therefore the sulfur content in steel before and after VD process is constant.