Effect of Different Natural Flake Graphite Additions on the High-Temperature Properties of a Dolomite-Carbon Refractory

摘要

The Bureau of Mines investigated the role of imported natural flake graphite in dolomite-carbon refractories used in steelmaking processes. Fundamental engineering data were obtained to enable the evaluation of substitute materials. Changes in oxidation resistance (2,000 F), hot strength (2,750 F), and deformation under load (2,750 F) caused by 10-wt-pct additions of five different kinds of natural flake graphite and increasing quantities (0 to 30 pct) of a 90-pct-carbon natural flake graphite were studied. Results indicated that carbon purity of 10-wt-pct-graphite additions did not influence hot strength deformation under load. Additions of a boron-treated graphite caused significantly higher strength and lower deformation under load at high temperatures, while an addition of ball clay significantly reduced strength and increased deformation.