What are the common defects in the manufacturing process of construction machinery casting?

During the manufacturing process of construction machinery casting, common defects can adversely affect the quality and performance of the castings. The occurrence of these defects is due to the combined effect of multiple factors, including issues in process control, design rationality, and material quality.

Porosity and bubbles are one of the common defects that may form during the casting process due to the presence of gas in the molten metal or the generation of gas during solidification. These pores and bubbles may affect the density and strength of the casting, reducing its quality. Inclusions are also one of the common defects. They may be sand, dust, paint residues and other impurities that are mixed into the molten metal during the casting process. These inclusions may cause the casting to have rough surfaces or holes, affecting its appearance and performance.

Thermal cracks are caused by the thermal expansion and contraction of metal, resulting in uneven temperature gradients during the solidification process. These cracks may affect the integrity and strength of the casting, reducing its service life.

Shrinkage defects are one of the common defects in the casting process. Castings will shrink during the cooling process. If the gate and cooling system are not designed correctly, it may cause shrinkage defects in the castings, such as shrinkage cavities, shrinkage porosity, etc., affecting its quality and performance.