Experimental observation and computer simulation on non-equilibrium grain-boundary segregation kinetics of phosphorus

Abstract

An experimental study and computer simulation on non-equilibrium grain-boundary segregation kinetics and the critical time for phosphorus in 12 CrlMoV steel (which is used in steam pipeline of ships) are put forward in this paper. The segregation level of phosphorus with solution temperature 1050°C at the isothermal holding temperature of 540°C, have been measured at grain-boundaries. A non-equilibrium grain-boundary segregation kinetics curve of phosphorus is given. The critical time for phosphorus non-equilibrium grain-boundary segregation is about 500 h at 540°C for the experimental steel. When the holding time is longer than 1500 h, non-equilibrium segregation disappears and the level of segregation reaches full equilibrium. The simulation using the kinetic equations of non-equilibrium grain-boundary segregation is in good accordance with the experimental observation for phosphorus in steel 12Cr1MoV. The non-equilibrium grain-boundary segregation kinetic model is therefore proved.

Keywords

steels / grain boundaries / segregation / computer simulation