The ingredient and phases of solid phase slag without remelting liquid slag air cooling and with liquid-slag reaction remelting slag

air cooling of slag 70% CaF

2

-25% Al

2

O

3

-5% CaO for ESR of electrothermal alloy steel 0Cr21A16NbRE with normal remelting process (A =2800 A

V =30 V) are studied

and the burning loss of RE elements in liquid is analyzed. The results show that without remelting air cooling slag has not RE elements it locates in CaF

2

-CaO • 2Al

2

O

3

-CaO • 6A1

2

O

3

sub-triangle. The solid phase slag with liquid-slag reaction can be divided into f

ive layers with different colors

difierent phase

the content of CaF

2

on the top is highest and decreases layer by layer

A1

2

O

3

increase simultaneously

RE oxide is found in layers and at the middle and bottom its content is higher

(Ce

La)x( A10

2

)  y is major RE oxide phase in slag

which density is high. It is obtained by calculation that slag oxidability is stronger in the middle and bot¬tom of slag

RE element in steel is oxided here. Increasing the Y

2

O

3

amount in slag is favourable to increase the RE element Y content in ESR ingot.