With gear steel 20CrMnTi producing by 80 t LD-LF-CC process

as [Al

]

  s decreases from 0. 030% to 0. 015%

the production cost per ton steel shall be decreased by 25. 8 yuan. In order to un-influence the cleanliness of liquid steel

in LD tapping the slag was strictly stopped

the 2 kg/t steel-clad aluminium was added with adding high basicity slag containing ≥70% CaO and ≤5% SiO

2

to carry out slag washing

argon blowing and feeding aluminium wire to [ Al

]

s 0. 015%

in LF refining

lime lump and AD powder ( Al + Al

2

O

3

) were added to modify slag ingredient

then feeding Ca- Si wire and soft-blowing argon for more than 10 min. Results by 5 heats test showed that with improved process

the cast billet had higher cleanliness with ( 14-15) x 10

-6

T [0

]

0. 012% 〜0. 015% [S

]

and 0. 012% -0. 018% [P

]

.