The effect of magnesium oxide (/c/c: 97. 60MgO

1.34CaO)

Calcium Oxide (/% ： 98. 70CaO

0. 55MgO) and alumina-magnesium) oxide (/c/c: 85. 57Al

2

O

3

11. 36MgO

2. 47CaO) crucible of 200 kg and 500 kg vacuum induction furnace on oxygen and sulfur content in melted nickel base alloy Inconel 690 (/% ：0. 01 - 0. 03C

27. 0 ~ 31. 0(2r

7. 0 ~ 11.0Fe) has been studied and analyzed. Results show that the oxygen content in alloy melted with alumina- magnesian oxide crucible is lowest i. e. (10 - 15) x 10

-6

[O

]

： with (50 - 60) x 10

-6

[S

]

; the sulfur content in alloy melted with calcium oxide crucible is lowest i. e. 10 x 10

-6

[S

]

with (27 - 48) x 10

-6

[O

]

. the sulfu

r content and oxygen content in alloy melted with magnesium oxide crucible are higher i.e. (50 〜60) x 10

-6

[S

]

and (24 ~ 35) x 10

-6

[O

]

.