Vacuum Melting Steel and Titanium: Extensive New Facilities at the Works of Jessop‐Saville Ltd.

VACUUM melting techniques have become necessary to deal with titanium and other metals which have great affinity for oxygen and other atmospheric gases when heated above certain temperatures. While it has been known for a long time that steel could be much improved by vacuum melting it required the impetus of the demand for titanium, mainly for the aircraft industry, and zirconium, for nuclear energy applications, before substantial vacuum melting facilities were made available. In addition it is only relatively recently that vacuum technology has made it possible to achieve pressures down to about one micron of mercury. It is these very high vacuum conditions that not only prevent oxidation of the contents of the melt but also markedly reduce the gaseous impurities in the metal. With these new techniques, purity in terms of oxygen content can be such that there are less than 10 parts per million of O2.