| 摘要 |
PCT No. PCT/SU79/00115 Sec. 371 Date Sep. 30, 1980 Sec. 102(e) Date Sep. 25, 1980 PCT Filed Nov. 19, 1979 PCT Pub. No. WO80/01573 PCT Pub. Date Aug. 7, 1980.The method consists of maintaining constant the magnitude of the interelectrode gap. For this purpose a melting current is measured and averaged for a constant predetermined time interval, whereafter a derivative of an averaged value of the melting current is determined, an amplitude of oscillations of the melting current relative to the averaged values of the melting current is detected, and a derivative of the rectified amplitude of oscillations of this current is determined. Then the obtained data are compared, and from the results of this comparison the melting current is controlled in such manner that said values are reduced to zero. The apparatus for controlling the process of casting thin walled ingots using the electroslag melting method comprises a melting current pick-up having an output connected to the inputs of a comparison unit and of a determination unit for determining an averaged value of the melting current. The output of the determination unit is connected via a detecting unit for detecting an amplitude of oscillations of the melting current and via a first derivative unit for determining a derivative of this detected amplitude to a third input of a logic unit. The output of the detecting unit is connected to a second input of the unit whose first input is connected via a second derivative unit 13 for determining a derivative of the averaged value of the melting current to the output of the determination unit. The output of the logic unit is connected via the comparison unit to the input of the control unit. |
