Why is the strength and shape of nodular cast iron higher than that of grey cast iron and worse than that of gray iron?
The graphite in spheroidal graphite cast iron is spherical, and the graphite in the gray iron is in flake shape. Compared with flake graphite, spherical graphite, destructive effect on the matrix separation effect, stress concentration degree is relatively small, relatively small for the effective bearing area decreases, the substrate can get more fully, so the strength of ductile iron and plastic (mechanical properties) higher than that of grey cast iron.The flow of nodular cast iron is the iron, shrinkage is relatively large, more difficult to control the process of gray iron (spheroidization and inoculation), so a difference of gray iron casting
Casting performance: also known as casting process performance.Mainly include1) flow performance, mold filling capacity;2) shrinkage, the ability to shrink when casting is solidified;3) segregation means the unevenness of chemical composition;4) inhalation and smelting;5) the performance of the gas absorbed during pouring.
The graphite in spheroidal graphite cast iron is spherical, and the graphite in the gray iron is in flake shape. Compared with flake graphite, spherical graphite, destructive effect on the matrix separation effect, stress concentration degree is relatively small, relatively small for the effective bearing area decreases, the substrate can get more fully, so the strength of ductile iron and plastic (mechanical properties) higher than that of grey cast iron.To cast graphite in the ball, the production process is more complex than gray iron, ductile iron casting than gray cast iron difference.
