Improvements in the manufacture of bessemer steel and thomas steel

摘要

Iron containing more than 0.2 per cent. silicon or more than 0.6 per cent. phosphorus is converted in a Bessemer or a Thomas converter respectively by the use during the whole or part of the blowing period with a blast containing at least 40 per cent oxygen, steam and little or no nitrogen. The nitrogen should never exceed 21 per cent. The blast may be introduced from the top, bottom, or sides of the converter and may contain some carbon dioxide in addition to the steam. The exhaust gases may be burned in the free converter space. In an example using a blast having a 2 : 1 ratio of 94 per cent. oxygen to steam and containing 4 per cent. nitrogen, a steel containing 0.0035 per cent. nitrogen was obtained.