Analysis of the Effect of Nitrogen on Cold Shortness Behavior of Steel with the Electron Structure Parameters of Phase Interface
Based on the empirical electron theory of solids and molecules (EET), the phase interface electron structure of Fe4N/a-Fe、AlN/γ-Fe、AlN/γ-Fe-C(Al) are calculated, and the reasons that the cold shortness is resulted from nitrogen as well as the add of Al element is helpful to the removal of cold shortness are analyzed with the use of the interface conjunction factors such as,σ and. The calculated results are as follows. The discontinuous electron density difference of phase interface Fe4N/a-Fe under the first order approximation results in the remarkable strengthening effect as well as the significant decrease in toughness and ductility, demonstrating the reason that nitrogen can cause cold shortness; as the electron density difference on AlN/γ-Fe、AlN/γ-Fe-C(Al) phase interface is very large and the continuous number of the phase interface is very small, the add of Al can hinder the growth of grain, as a result, the austenite grain is significantly refined and the removal of cold shortness caused by Fe4N can be achieved.
Jianzhong Wang and Jingang Qi
G. L. Yin et al., "Analysis of the Effect of Nitrogen on Cold Shortness Behavior of Steel with the Electron Structure Parameters of Phase Interface", Advanced Materials Research, Vols. 299-300, pp. 151-154, 2011