The data from reports of 35 laboratories, comprising more than 2,000 analytical determinations, indicate that the vacuum-fusion method yields accurate r esults for the oxygen contents of plain-carbon steels either aluminum-killed, siliconkilled, or of the rimming type; the aqueous-iodine method yields accurate results for some types of killed steels and low results for other steels; more data, and particularly more concordant data, are necessary to define the accuracy of the other methods employed in this cooperative analysis.The vacuum-fusion procedures are reviewed and recommendations given for obtaining optimum results by this method. CONTENTS Page

The slip-casting process, which is widely used in ceramics, has not been generally applied to the preparation of crucibles from special refractories, which lack the property of plasticity. However, enough plasticity to make slip-casting feasible can be developed in some of the special r efractories by fine grinding and treatment with acid. Thin-walled crucibles of alumina, beryllia, zircon, zirconia, and electrically fused thoria were cast from aqueous slips, and bricks 5 cm thick were made by a modified process . Magnesia crucibles could not be cast from aqueous slips but wer e formed s uccessfully from a suspension of fin ely ground magnesia in absolute alcohol.

No abstract

No abstract

No abstract