Minimization of Cracks on the Narrow Face of Cast Slab for HCMA Grade Steel

Transverse corner cracks are among the most common defects in high carbon and high carbon micro-alloyed grade slab casting. Calculation and analysis were done to minimize the negative strip time of mold oscillation, which is responsible for reducing the depth of the oscillation mark formed on the slab surface. The value of negative strip time decreases with an increase in the frequency of mold oscillation. Based on the trial results, it was suggested that the oscillation proportionality be adjusted from 1.2 to either 1.25 or 1.3. This adjustment will reduce the depth of oscillation marks and the tendency to form transverse cracks. The transverse crack on the narrow face of the slab was examined for crack analysis and compositional analysis. Microstructural analysis revealed that the crack has no branching and consists of an iron scale inside it. Furthermore, it is observed that the crack propagates across the allotriomorphic ferrite grains.