To realize the coordinated control of lubrication and heat transfer of mold flux, the accurate measurement of initial crystallization temperature (Tc−initial) of mold flux is an essential guarantee for its development and application. In this paper, four probes and LCR digital bridge were applied to measure the electrical conductivity by alternate current (AC), and the optimal measurement parameters were determined as frequency, voltage, slag liquid level height, and probe insertion depth were 6 kHz, 50 mV, 20 mm, and 9 mm, respectively. The Tc−initial of mold flux was acquired accurately by the AC conductivity method based on the principle of the curve slope variation at solid-liquid transition. The accuracy of Tc−initial were verified by tests of digital optical microscopy with an isolated observation system in an infrared furnace (IR-MOP), differential scanning calorimetry (DSC) and X-ray diffraction (XRD), so as to provide theoretical guidance and technical support for the measurement of the Tc−initial of mold fluxes with high speed and accuracy.
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