Mold Powder Topics
3.Construction of continuous casting powder
Continuous casting flux is a
mixture of oxides whose main component is CaO-SiO2, with
fluoride and carbon added. In the CaO-SiO2 system, the
mass% is 1:1, that is, CaO/SiO2 (basicity) 1, and the
melting point is
will be the lowest. However, considering the casting temperature of
steel, the melting point of CaO-SiO2 alone cannot be said
to be sufficiently low. Therefore, add oxides such as Na2O
and fluorides such as CaF2 to obtain an appropriate
viscosity and melting point.
adjust. Also, carbon powder is added to adjust the melting rate. A
melt containing SiO2 generally has a network structure of
SiO2. Since the network structure of SiO2 is a
large fluid unit, it has a higher viscosity than monoatomic melts such
as metals.
The network structure of SiO2 is divided by the addition of basic
oxides and fluorides, and the flow unit becomes smaller, so the
viscosity decreases.
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|---|---|
| Phase diagram of CaO-SiO2 | Structure of SiO2 |
| after, http://www.engineering-eye.com/THERMOCALC/details/case/13.html |
after, https://ja.m.wikipedia.org/wiki/%E3%83%95%E3%82%A1%E3%82%A4%E3%83%AB:SiO2_-_Glas_-_2D.png |