Microstructure Stabilities of Newly Developed Hot‐Working Die Steel and H13 Steel at Elevated Temperature

Herein, the microstructure stability of a newly developed hot‐working die (HWD700) steel at elevated temperatures up to 700 °C is investigated using transmission electron microscopy (TEM), selected‐area diffraction, energy‐dispersive spectrometer, and high‐resolution microscope. The results show that HWD700 exhibits higher thermal than commercial H13 when temperature °C. After quenching tempering, high densities intra‐lath rodlike inter‐lath spherical MC nano‐carbides strip‐like M 7 C 3 are observed in steel. These carbides remain nanoscale For comparison, rod‐shaped tempered tend coarsen transform into larger 23 6 650 TEM observation further reveals interface misfit between nano‐carbide matrix as low 0.88%, lower 14.8% This can be main reason for improved by pinning dislocations grain boundaries thereby hindering recrystallization process an temperature.