The chemical ingredient

physical-chemical properties and crystallized mineralogical phases of mold flux and slag rim for 200 mm slab of high aluminium non-magnetic steel 20Mn23AlV (% ： 0. 14 ~ 0. 20C

21. 50 ~ 25.OOMn

1. 50 ~2.50Al

0. 04 ~0. 10V) during concasting has been compared and analyzed. The ingredient of mold original flux is (/%) 31.91CaO

30. 30SiO

2

6.58A1

2

O

3

1. 12MgO

3.02MnO

7. 73Na

2

O

7. 10F. Results show that after starting casting in 15 min

the SiO

2

content in mold flux and in slag rim respectively decreases to 22% and 18%

the Al

2

0

3

content in that respectively increases to 20. 5% and 25. 5%

and the

basicity of that increases from 1. 05 of original flux respectively to 1. 7 and 2. 0 ； this moment the melting temperature and viscosity of mold liquid flux and slag rim increase obviously while the break temperature decreases markedly ； the change range of ingredient and physico-chemical properties of slag rim are all larger than that of mold liquid flux； and as casting for more than 15 min

the ingredient and properties of mold liquid flux and slag rim tend to stability. The precipitation of high melting-point phase gehlenite is an important cause to form the slag rim in mold.