Mechanical Properties and Thermal Expansion Characteristics of Low Thermal Expansion Ductile Cast Iron with same Nickel Equivalent (NiE)
Low thermal expansion ductile cast iron is expected to become a new structural material with high dimensional stability against temperature change. We tried to develop a new low thermal expansion ductile cast iron by means of adding C and Si to Superinver alloy. In this study we prepared four kinds of ductile cast irons whose Co contents vary from 0% to 12 %, and investigated about the effects of Co content and solution-treatments on several main characteristics such as coefficient of thermal expansion and mechanical properties. The results obtained are as follows: With increase of Co content the amount of martensite increases but this martensite can be inverse-transformed to austenite totally or greatly by solution-treatment followed with water-quenching. In the case of Co content less than some 9 % the ability of relatively larger plastic deformation can be expected in inverse-transformed austenite.
Adel Nofal and Mohamed Waly
M. Hatate et al., "Mechanical Properties and Thermal Expansion Characteristics of Low Thermal Expansion Ductile Cast Iron with same Nickel Equivalent (NiE)", Key Engineering Materials, Vol. 457, pp. 380-385, 2011