×

Production of ultra low carbon steel by the basic oxygen process

  • US 4,397,685 A
  • Filed: 03/26/1982
  • Issued: 08/09/1983
  • Est. Priority Date: 03/26/1982
  • Status: Expired due to Fees
First Claim
Patent Images

1. In a process for the production of low alloy steel comprising decarburizing a ferrous melt contained in a vessel by injecting oxygen through a lance into the melt from above the surface of the melt, wherein the lance height between the lance tip and the melt surface when there is a lessening of the carbon monoxide evolved is from about 30 to 40 oxygen nozzle diameters, the improvement whereby low alloy steel having an ultra low carbon content is produced comprising the steps of:

  • (a) injecting an inert gas into the melt from above the surface of the melt at a flow rate of from about 40 to 110 percent of the oxygen lance rating when the carbon content of the melt is less than about 0.06 weight percent;

    (b) adjusting the flow of oxygen through the lance to be from about 10 to 40 percent of the inert gas flow rate;

    (c) lowering the lance height to between about 30 to 60 percent of the normal lance height; and

    (d) continuing the injection of oxygen and inert gas into the melt until low alloy steel having the desired ultra low carbon content is produced.

View all claims
  • 4 Assignments
Timeline View
Assignment View
    ×
    ×