7. Case Studies on Localized Deformation Processes in High-Alloy Fe–16Cr–6Mn–xNi–0.05C Cast Steels

This chapter is together with Chap. 6 the principal part of this book. This chapter provides detailed results on the application of the in situ characterization techniques introduced in Chap. 5 in terms of three case studies: (i) the microscopic strain localizations during plastic deformation, (ii) the temporal evolution of deformation processes and (iii) the macroscopic strain localization during plastic deformation. The part on microscopic strain localizations provides high-resolution (sub-µm) results of strain field calculations obtained during both tensile deformation at different temperatures (RT, 100 and 200 °C) and cyclic deformation at room temperature. Furthermore, the magnitude of shear for individual microstructural constituents (austenite, ε-martensite and α′-martensite) was experimentally determined and shows a good agreement with theoretical calculated values. The part on temporal evolution of deformation processes shows that the acoustic emission is a powerful tool to study the kinetics of deformation processes since it allows to separate acoustic signals belonging to different sources such as dislocation movement, twinning, formation of stacking faults and martensitic phase transformation. The part on macroscopic strain localizations demonstrates well that the combination of different in situ characterization techniques such as digital image correlation, infrared thermography and acoustic emission applied to the Portevin–Le Chatelier effect can gain a deeper knowledge and understanding on ongoing processes and material behaviour.