| 摘要 |
The invention relates to ferrous metallurgy, namely, to the method of obtaining the steel ingot. A method of obtaining the steel ingot includes the filling of casting mold with metal, preheating the basic part of the ingot by carbon-containing plasma jet, which is started at the end of time, which makes 0.05-0.06 of duration of the time of crystallization of ingot under natural conditions ( ), and the duration of time of action of plasma preheating makes . Then the preheating is stopped, and after an interval of the preheating of base part of the ingot by plasma is conducted again during . In this case, axial density of heat flow is set depending on the average density of heat flow in the nozzle section of plasmatron and reduced length of plasma jet, and average density of heat flow in the nozzle section of plasmatron is determined taking into account the flow of the plasma-forming gas, averaged-mass enthalpy of plasma jet and area of the exit nozzle of plasmatron. Invention ensures the increase of structural uniformity of the metal of ingot, reduces the rate of formation and the depth of shrinkage cavity of ingot, the decrease of value of its main trimming and number of surface defects on it.
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