Specific Features of Static, Impact, and Fatigue Fracture of the 0.09%C-0.08%Mo-0.03%Nb-0.06%V Steel with Ultrafine-Grained Structure
The mechanical properties and fracture mechanisms of the 0.09%C-0.08%Mo-0.03%Nb- 0.06%V steel in the initial state and with the ultrafine-grained (UFG) structure obtained by equalchannel angular pressing (ECAP) have been estimated. The investigation included the static and cyclic tensile tests, the impact tests at room and lower temperatures with automatic recording of force-displacement diagram, and the analysis of both the fracture surface microrelief and the evolution of plastic deformation zone by replica method. It is established that the grain refinement increases the ultimate strength and yield strength, but decreases plasticity and impact toughness and raises fatigue growth rate and the critical temperature of ductile–brittle transition. The dynamic fracture toughness of the material after ECAP as compared with that of the material with the initial structure decreases due to the raising of the critical brittleness temperature.
Yuri Estrin and Hans Jürgen Maier
L.R. Botvina et al., "Specific Features of Static, Impact, and Fatigue Fracture of the 0.09%C-0.08%Mo-0.03%Nb-0.06%V Steel with Ultrafine-Grained Structure", Materials Science Forum, Vols. 584-586, pp. 281-286, 2008