Under the same austenitizing process parameters, the change of carbon content in austenite with modulus is shown in the figure.
It can be seen that at lower t γ, low MS ductile iron is easier to enrich more carbon in high temperature austenite during austenitizing process, which is mainly related to the higher pearlite content in as cast structure, as shown in Fig. (a). However, when t γ increases to higher temperatures (920 ℃ and 960 ℃), the dissolution and diffusion of graphite become the mainstream. Therefore, with the increase of modulus, the carbon content in austenite increases.
