抄録
(A) Silicate inclusion.
1) The author investigated on the silicate inclusion of steel from melt to ingot by Dickenson method. 2) Silicate are diminished when the slag composition is higher acidic and the oxygen contents of molten steel is small. 3) Also, silicates are decreased by the use of Si-Mn and Fe-Ti as deoxidiser.
4) Addition of Fe-Mn during the boiling period is effective for diminition of silicate. 5) Generally, silicates of ingot show maximum value at inside of the bottom and outside of the top. 6) Large Mn-silicate remains in ingot when the addition of Mn is too much
(B) Flakes.
1) Existence of flakes can be detected by deep etching with alcoholic solution of HNO3. 2) Segregations, cracks and low-silica-silicates of ingot give much effect on the formation of flakes. 3) Forged steels in which flakes appear, have partially martensitic structure caused by segregation of alloying elements. 4) Slow cooling after forging is most effective for prevention of flakes.
