Healing porosity cavities in a 300 mm thickness continuous casting slab by mechanical heavy reduction

Abstract

This work conducted an exploring study to minimize porosity cavities in a 300 mm × 2000 mm slab by mechanical heavy reduction when it has solidified. Real density measurements of slab samples indicated that, with a heavy reduction of 20 mm to slab after behind its solidification end, slab center was much denser and much more consistent. Porosity volumes at 1/4 and 1/2 width regions of slab were minimized from 5.19 × 10−4 cm3/g to 1.29 × 10−4 cm3/g and from 2.27 × 10−4 cm3/g to 1.05 × 10−4 cm3/g, respectively. Original Position Statistical-Distribution Analysis (OPA) of larger sampled slabs indicated that the heavy reduction was efficiently penetrated from slab surface into center to heal porosity cavities. Obtained results indicated positive influences of heavy reduction in healing porosity holes in slab even after solidification, when the temperature gradient of slab surface and center was about 280 °C.