The part mold made of cast steel is a cast steel mold. Its performance is similar to that of cast iron, but its strength is better than that of cast iron. Steel castings are prone to defects such as bubbles and inaccurate angle positioning in the casting process, and long-term use may cause shell rupture.

Due to the influence of many factors, defects such as blowholes, pinholes, slag inclusions, cracks and pits often appear in hot metal products of iron castings.