| 摘要 |
A method is provided for optimally operating a wheel-type continuous caster such that solidification porosity and macrosegregation in the continuous strand thus produced is substantially minimized while casting speed is substantially maximized subject to that condition. Continuous casting is adjusted from an operational condition where solidification porosity is forming by changing the solidification rate so as to cause the terminus of the solidification zone to shift location in the direction of increasing metalostatic pressure until the point where solidification porosity ceases to form or its occurrence is minimized; further provided that in the vicinity of the solidification terminus the direction of increasing metalostatic pressure is maintained counter to the direction of casting. Conversely, from an operational condition where solidification porosity is not forming, solidification rate is changed so as to cause the solidification terminus to shift location in the direction of casting and in the direction of decreasing metalostatic pressure until formation of solidification porosity impends. Advantageously, this system may be utilized continuously to correct continually for perturbations during continuous casting. Additionally, the invention comprehends a continuously cast strand of indefinite length produced by the above method wherein macroscopic solidification porosity has been substantially eliminated and macrosegregation has been substantially minimized. This advance is especially important for alloys that are particularly susceptible to solidification bridging defects in casting, such as those alloys having a large freezing range.
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