Fracture Behaviour and Temper Embrittlement Induced by NGS of Phosphorus
The non-equilibrium grain-boundary segregation (NGS) isotherms and its kinetics serve to provide a more complete understanding of inter-granular segregation behavior in relation to mechanical properties, not only for the engineering steels but also for a wide range of structural alloys. The NGS of phosphorus and temper embrittlement dynamics on the same heat treatment condition at the same isothermal holding time in two Cr-Mo steels, 12Cr1MoV and 2.25Cr1Mo, was experimentally studied. The fracture behaviour was also observed by tensile tests in situ in a scanning electron microscope (SEM). Results show that both the concentration of phosphorus atoms in grain boundaries and the degree of embrittlement reaches a maximum at the critical time. It can be satisfactorily elucidated by the temper embrittlement mechanism of NGS caused by cooling from solution temperature to isothermal holding temperature.
M.H. Aliabadi, Qingfen Li, Li Li and F.-G. Buchholz
Q. F. Li et al., "Fracture Behaviour and Temper Embrittlement Induced by NGS of Phosphorus", Key Engineering Materials, Vols. 324-325, pp. 33-38, 2006