For lost foam cast iron, surface wrinkle skin is […]
For lost foam cast iron, surface wrinkle skin is the most common defect. Because free carbon does not easily penetrate into the surface of the casting, but is deposited on the surface of the casting and mold. These high-temperature carbons are locally accumulated too much, causing the surface of the casting to be rough, which is the wrinkle skin defect.
The wrinkle skin defects of lost-form cast iron parts can be divided into: corrugated wrinkle skin, drip-shaped wrinkle skin, cold partition wrinkle skin and slag-shaped wrinkle skin. Generally, the corrugated wrinkle skin is shallower, and the latter three are deeper . The depth of the light is ~, the serious is about 0.11 mm10 mm. The surface of such defects is often covered with light and shiny carbon flakes, and the depressions of the defects are filled with soot and carbon, which are surface carbon defects. Wrinkled skin defects often appear at the location where the liquid metal finally flows or the "cold end" of the liquid flow.