“…As it is well known, the surface quality of molds influences both surface quality of plastic products and service performance of molds. The surface quality of molds is closely bound up with polishing process of molds and cleanliness of mold steels (Bakke et al, 2005;Way, 2001). It is believed that nonmetallic inclusions in the interior of mold steels, especially brittle inclusions, such as oxide inclusions and silicate inclusions, affect mechanical properties, workability, manufacturability and surface finishing of the molds (Meurling et al., 2001;Fernandes et al, 2003a,b).…”