Microstructure evolution and damage mechanism of nanostructured bainitic steels under cyclic high energy impact

The microstructure evolution and damage mechanisms of nanostructured bainitic steels under cyclic high-energy (similar to 1000 J) impact were studied. The characterization results of impacted samples show that several zones of stress layer, deformation zone and transition zone can be divided based on a gradual increase in the volume fraction of retained austenite. Corresponding well to the simulation results, the measured residual stress shows a peak value at a distance of 10 mm beneath the impacted surface, which results in a large amount of transformed martensite and localized high strain in the deformation zone, thus inducing the nucleating of fatigue cracks and macroscopic microstructure failure.

Automated summary

The microstructure evolution and damage mechanisms of nanostructured bainitic steels under cyclic high-energy impact have been studied. The characterization results show the formation of stress layer, deformation zone, and transition zone based on the gradual increase in retained austenite volume fraction. The presence of transformed martensite and high strain in the deformation zone leads to the nucleation of fatigue cracks and macroscopic microstructure failure.