(1) EPMA analysis of carbon content in austenite of ductile iron
① The effects of austenitizing temperature and austenitizing holding time on carbon content in austenite of nodular iron during austenitizing process;
② The correlation between matrix type and casting modulus of as cast ductile iron and carbon content in austenite during austenitizing process;
③ Comprehensive analysis and evaluation of austenitizing process of ductile iron.
(2) Study on Microstructure and technological factors of Austempered Ductile Iron
① The effects of as cast microstructure and austempering process on Microstructure of austempered ductile iron were investigated;
② The fine structure of austenite in the matrix of austempered ductile iron was analyzed;
③ The distribution behavior of carbon element between acicular ferrite and high carbon austenite in matrix of austempered ductile iron was studied.
(3) Correlation between as cast microstructure, austempering process, casting wall thickness and mechanical properties of Austempered Ductile Iron