The characteristics of as cast high strength and high plasticity pearlitic ductile iron are as follows:
(1) Compared with ordinary nodular cast iron, although they are all pearlite and ferrite mixed matrix, the comprehensive properties of as cast high strength and high plasticity Pearlite Nodular Cast Iron with various strengthening measures are better than ordinary nodular cast iron.
(2) Compared with Si solution strengthened ferritic nodular cast iron, the matrix of Si solution strengthened ferritic nodular cast iron is ferrite, while the matrix of as cast high strength and high plasticity pearlitic nodular cast iron is pearlite + ferrite mixed structure, and its strength and low temperature impact property are obviously better than that of Si solution strengthened ferritic nodular cast iron.
(3) Compared with austempered ductile iron, the matrix of Austempered Ductile Iron transforms into austenite after Austempered heat treatment, and its comprehensive properties are much higher than that of as cast high strength and high plasticity pearlite ductile iron. However, isothermal quenching heat treatment needs expensive equipment, labor and energy consumption, and also causes casting deformation due to heat treatment. As cast pearlite ductile iron with high strength and high plasticity can obtain high strength and plasticity without heat treatment (or low-cost heat treatment).
The figure is the summary of several types of ductile iron standards at home and abroad. It can be seen that the mechanical properties of as cast high strength and high plasticity ductile iron are between ordinary ductile iron and austempered ductile iron, which fills the gap between them.