METHOD OF DECARBONIZATION OF STEEL MELT Russian patent published in 1999 - IPC

FIELD: methods of decarburization of steel melts in production of steels with high content of chromium by oxygen blowing. SUBSTANCE: method includes continuous measurement of rate of decarburization of steel melt. Depending on measured values, amount of blown oxygen is regulated. Calculated preliminarily are the following parameters: duration of oxidation phase of Al-Si to beginning of decarburization process; duration of main decarburization phase following the phase of Al-Si oxidation up to attaining the point of transition from reaction of decarburization to metal oxidation, and rate of decarburization during the phase of main decarburization. Amount of blown-in oxygen, directly after phase of Al-Si oxidation, is rapidly increased until rated rate of decarburization is attained, specific for phase of main decarburization. Rate of decarburization is maintained, mainly, constant during the phase of main decarburization due to variation of amount of blown-in oxygen. Directly after phase of main decarburization amount of blown-in oxygen is continuously reduced so that the rate of decarburization is continuously decreased in time at preset time constant. Design formulas are offered for regulation of method parameters. EFFECT: accurate control of decarburization of steel melt with high chromium content by oxygen blowing into melt with prevented undesirable oxidation of chromium in attaining high decarburization of melt and minimal slagging of metal. 3 cl, 2 dwg