Pores and Carbon Inclusions

Problem Description:Coated sand contains phenolic resin. If the degassing is poor or the resin is not burned completely, it is easy to form pores, carbon inclusions and black spots on the surface or inside the casting.

Solution:

• Incorporate vent holes into the shell mold design and avoid excessive heat accumulation in thick wall areas.
• Use low carbon residue resin or environmentally friendly coated sand to reduce pyrolysis by-products.
• Control the pouring temperature and speed to avoid rapid volatilization and gas generation.