At present, there are two kinds of as cast high strength and high plasticityin China：
The first one is high strength and high plasticity ductile iron with ferrite matrix as the main body, which is characterized by keeping the plasticity (elongation) index of the original brand unchanged and only improving the tensile strength. Their tensile strength is generally not very high (about 600 MPa), although the plasticity has not changed, but because the strength has been improved to a certain extent, designers can reduce the thickness of thin wall and reduce the mass. This kind of high strength and high plasticity ductile iron is relatively easy to obtain, and also easy to be accepted by the design department.
The second is high strength and high plasticity ductile iron with pearlite matrix. This type of high strength and high plasticity ductile iron is characterized by high strength (above 700 MPa), certain plasticity (elongation ≥ 5%), good comprehensive properties, especially high fatigue property and high wear resistance. The production of this kind of ductile iron is more difficult than that of the first kind, but the market demand is more urgent. The author will focus on the pearlite matrix as cast high strength and high plasticity ductile iron.