1958 Volume 44 Issue 12 Pages 1360-1365
The present report is an outcome of the results obtained during the study of the composition and process of formation of the so-called sand marks produced in steel ingots by thepresence of non-metallic substances. The results are summarized as follows:
1. Scum patches are produced by the corrosion and spalling of the runner bricks.
2. α-Alumina aggregates are produced by oxidization of the aluminum deoxidizer during formation of steel ingots by pouring. Such aggregates are never produced if aluminum is not used.
3. Non-metallic inclusions produced in bearing steel, when extracted by dissolving the steel with hot sulfuric acid, are found to consist mainly of Spinel and a little amount of α-Alumina and Quartz.