Methods for Characterising the Precipitation of Nanometer-Sized Secondary Hardening Carbides and Related Effects in Tool Steels

Abstract

AbstractNanometer-sized secondary hardening carbides are the most relevant microstructural constituents regarding the properties of tool steels. Due to their extreme fineness, direct inspection by microscopy is difficult and time consuming despite the progress recently achieved, e. g. by energy filtering transmission electron microscopy. Indirect methods are therefore additionally employed to obtain more detailed information on the processes taking place. Differential scanning calorimetry and in-situ hot hardness testing are demonstrated as powerful methods for the determination of kinetic data. In combination with results from a recently developed tensile specimen and test procedure for hard materials with low ductility, more detailed conclusions can be drawn on the effects of secondary hardening carbides on the strength and the thermal stability.