Abstract
Electron beam melting is thought to deoxidize and remove inclusions by high-temperature and high-vacuum melting. A rod melting technique using 250 kW EB furnace was applied to stainless steels and resulted in the following:
Deoxidation is enhanced by the CO degassing reaction, and the adjustment of feeding material composition and the controlling of melting energy allow a total oxygen content (T.[O]) of 15 ppm or less. The removal of inclusions occurs as the deoxidation reaction proceeds, resulting in a reduction in their amount to 1/10 per EB melting. The effect of removal is remarkable with increasing size of the inclusions. It is considered that the majority of inclusions can be removed by the decrease in oxygen accompanied by their decomposition and then by the reaction of decomposed oxygen with carbon.
The results confirmed higher cleanliness for inclusions than achieved by the conventional methods and production of an ultra-fine wire of 30 μm diameter without breakage during drawing.
