Refining steel with lightweight volatile scavenging agents - in form of compressed body having controlled dissolution rate to reduce smoking

摘要

Steel is refined by immersing in the melt a refractory covered vertical rod having a consumable body on its end formed of a pressed mixt. of an active substance having limited solubility in the steel e.g. Ca source, and an inactive material e.g. Fe, Al or alloying elements. The rate of dissolution of the body is controlled by appropriate choice of compsn. and shape so that active substance is released at a rate which does not exceed its solubility limit. The active material may be Ca or an alloy thereof e.g. CaSi, CaMnSi, CaSiBa, CaSiBaAl, CaC2, CaCl or Mg. The inactive material may be Fe, Al or elements which will alloy with the steel. The smoke normally associated with such methods is reduced or eliminated.