Abstract: Currently, steel plants mainly use copper-coated steel wire to measure the thickness of the liquid slag layer in the mold, but this method lacks standardized judgment criteria and accurate evaluation. In this study, a high-frequency induction furnace was used to simulate the mold's thermal environment, and copper-coated steel wire was employed to measure slag layer thickness. The post-measurement characteristics of the copper-coated steel wire were analyzed by SEM-EDS. Then, its formation mechanism was analyzed, and the judgment method was optimized. The results show that the powder layer and the upper part of the sintering layer do not reach the copper melting point (1 083 ℃) with no obvious change on the surface of the copper-coated steel wire. The temperature of the lower part of the sintering layer is over 1 083 ℃, after the copper melts, the exposed steel wire oxidizes to black. As the liquid slag layer heats up, the wire gets immersed and turns bright white. This parts not fully covered oxidize slightly, appearing grey. The length of the grey and white sections indicates the slag layer's thickness. This judgment method has been verified in the continuous casting site, but its accuracy is not as good as double-wire wetting method. 

Key words: continuous casting, mold flux, liquid slag layer thickness, copper-coated steel wire, wetting method