USE OF ARGON TO PREPARE LOW-CARBON, LOW-NITROGEN STEELS IN THE BASIC OXYGEN PROCESS

摘要

ABSTRACTThe nitrogen content of low carbon steel madeby the basic oxygen process is minimized by:(a) introducing nitrogen-free fluid into thevessel before the nitrogen content of the melt hasreached its minimum level,(b) adjusting the flow rate of the nitrogen-freefluid to maintain total off-gas flow rate at least equalto that which would have been produced without the nitrogen-free fluid at the time in the refining process when thenitrogen content of the melt reached its minimum level, and(c) the injection of nitrogen-free fluid throughoutthe remainder of the oxygen blow.A preferred additional or alternatively separatestep involves minimizing the nitrogen content of BOP steelby purging the vessel headspace with a nitrogen-free fluidprior to reblows.This is a divisional application of applicants'copending patent application, Application No. 288,670,filed October 11, 1977, having a priority date of January 11,1977.