Production of alloys in the Fe–Co system with an oxygen concentration below 10 ppm

Abstract

A fundamentally new solution of the challenge of producing alloys in the Fe–Co system with an oxygen concentration below 10 ppm (10^–3%) has been for the first time justified and demonstrated. A thermodynamic analysis showed that decreasing the pressure of the gas phase over the melt significantly increases the deoxidizing power of carbon. At cobalt and carbon contents characteristic of soft- and hard-magnetic alloys and a total pressure of 0.01 atm, the oxygen concentration was 10–1 ppm (10^–3–10^–4%). With increasing cobalt content of the melt, the deoxidizing power of carbon increases. The curves of the oxygen solubility in carbon-containing iron–cobalt melts pass through a minimum, which shifts toward lower carbon contents with increasing cobalt content of the melt.