What impact does the performance of ductile iron pieces

Graphite shape The most representative of the graphite shape is spherical. The quality of the nodular cast iron is generally assessed by the rate of spheroidization. Graphite more rounded, small, more uniform distribution of the metal matrix of the split and the stress caused by the smaller, the better the performance of ductile iron. Graphite shape is divided into six, three or more qualified, the ball rate to reach more than 75%.
The matrix structure of the nodular cast iron varies depending on the grade. The body structure of the ductile iron for Orlyst Machinery is mainly composed of ferrite and pearlite, and also includes a small amount of cementite and phosphorus eutectic. Ductile iron in the ferrite content, pearlite content is small, then the toughness is good, low strength; the other is the high strength, poor toughness. Orester Machinery Corporation commonly used QT400-15, QT450-10 grades are ferrite as the main matrix of ductile iron, pearlite content to be controlled at 20% or less. Cementite, phosphorus eutectic these two organizations in my company to use the ductile iron is harmful organization, must be controlled at 2% or less, otherwise the casting strength, toughness are poor.