Speaker
Description
Grain growth in the austenite (γ-Fe) single-phase region was studied under isothermal annealing conditions at temperatures of 1050 °C, 1150°C, 1250°C and 1350 °C for 2400 seconds by high-temperature laser scanning confocal microscopy (HT-LSCM). The presentation will critically address the potential and limits of HT-LSCM for in-situ grain growth observations.
Results for systems of pure γ-Fe (Fe > 99.98%), Fe-P with 0.026% P, 0.044% P and 0.102% P as well as Fe-0.20%C-P with 0.06% P, 0.10% P, 0.16% P will be presented. The arithmetic mean of grain sizes (determined with ASTM E112) as well as the grain size distribution, both resolved in time, depend on temperature and chemical composition. This valuable information could be used to contribute to mathematical models of classic grain growth theory. Grain growth in pure Fe was supposed without the influence of solute drag or precipitation mechanisms and results provided the quantification of grain boundary mobility of pure iron. In binary Fe-P systems as well as in ternary Fe-C-P systems, grain growth was only inhibited by grain boundary (GB) segregation of Phosphorus (impurity induced solute drag effect), allowing conclusions on the solute drag effect.
The presentation will end with an outlook on ongoing and future research activities.