Impact wear and mechanical behavior of steels at subzero temperatures

In this study, the deformation behavior of three steels was studied at Arctic temperatures by controlled single and multiple oblique angle impacts. The results were compared with the mechanical properties of the steels determined at the corresponding temperatures. At subzero temperatures, the hardness and strength of the studied steels increased and their ability to deform plastically steadily decreased. In the martensitic steels, adiabatic shear bands were observed to form during the impacts at subzero temperatures, indicating that the deformation ability of the steels was critically impaired. At −60 °C, the adiabatic shear bands commonly acted as initiation sites for subsurface cracks. Moreover, the surface characterization of the test samples revealed formation of cracks and wear particles, which was connected to the opening of grain boundaries and martensite laths at low temperatures. Finite Element Modeling was also used to obtain more information about the impact event.