Gray cast iron is a cast iron with flake graphite, which is called gray cast iron because the fracture is dark gray when fractured. Gray cast iron is currently the most widely used cast iron, and its output accounts for more than 80% of the total output of cast iron.
Gray cast iron casting properties, cutting performance, wear resistance are very good. Its disadvantages are the low strength, ductility and toughness compared with other cast irons.
The use of gray cast iron as a butterfly valve material is generally suitable for mediums with weak acid and weak bases such as water and air, and is not suitable for use in pipelines containing perchloric acid and nitric acid.
