Refining of metal during portional electroslag casting of large-size ingots

The metal refining in portion electroslag casting of ingots made of the 2Kh13, 18Kh2N4VA, 9Kh, 9KhM, 5KhNM and 25KhN2MFA steels has been studied. The steel contamination by nonmetallic inclusions was studied by electrolytic dissolution of standard samples followed by chemical analysis of precipitates. It has been found that the technique of portion electroslag casting provides for low contamination of the metal by nonmetallic inclusions, gases and sulphur. The nonmetallic inclusion distribution in the ingots obtained by the above technique is much more homogeneous than in the ingots obtained by routine casting. The separate control of the liquid metal feed rate and the heat power in the method provide for small depth of the metal bath and for high temperature gradient that promotes suppress of axial and extra-axial liquation in the ingots. The ingots may be obtained from the liquid metal smelted by any technique