抄録
It is interesting that when molten steel has been treated with various synthetic slags, the latter is presumed to have some effect on the nonmetallic inclusions and the steel quality.
A bearing steel (C1.04, Cr1.5%) treated with synthetic acidic slag (A) was compared with a non-treated similar steel (B) with respect to inclusions and steel qualities. The deoxidizers used are Al, Al+ Ca-Si and Ca-Si.
The steel (A) contained more oxygen than the other steel (B), but with respect to the chemical composition, cleanliness, results of sand mark test and macro-etch test, both (A) and (B) were almost equal.
There were found elongated inclusions (A-type) in a bearing steel added with deoxidizer Ca-Si and treated with acidic slag. An examination of the inclusions by transmission electron diffraction showed that the inclusions consisted of a-tridymite or fayalite.
Therefore, the elongated inclusions in steel (A) presumably consisted of FeO-Si02 system.
Thus the aforementioned on the treatment of molten steel with synthetic slag evidenced that the slag treatment would control nonmetallic inclusions in steel.
