Micromechanisms of Ferrite-Pearlite Steels Fracture Under Cyclic and Impact Loading

Abstract

During operation, the railway axle is exposed to static, cyclic and dynamic loading that is accompanied by influence of corrosive environments. This causes the accumulation of structural and mechanical damages in the material, formation of corrosion and mechanical micro-defects that are potential sites of fatigue crack nucleation and growth. This requires the development of failure analysis methods that allow determining main mechanisms of ferrite-pearlite steels fracture on the micro scale level. The railway axle's material -the OSL steel -main regularities of temperature influence on fracture mechanisms in ferrite-pearlite steel type are shown. Qualitative and quantitative analysis of fracture surface of Charpy specimens tested at 20°C and -40°C was performed on micro scale level using SEM investigation.

Modification of Mechanical Properties of High-Strength Titanium Alloys VT23 and VT23M Due to Impact-Oscillatory Loading

“…When implementing a complete stress-strain diagram, the stability of the processes of deformation and fracture of materials is provided at all stages, including the stage of the formation and growth of the macrocrack in the material [41][42][43].…”

“…Thus, the authors have improved the technique of studying the crack growth in sheet materials using the method of complete stress-strain diagrams [41][42][43]. In the proposed method, the technical possibility of providing the continuity of the fracture micromechanism of the titanium alloy by type I + III is ensured by making identical central circular holes in specimens (Figure 1b).…”

Increasing Low-Temperature Toughness of 09Mn2Si Steel through Lamellar Structuring by Helical Rolling

“…Analyzing the data in Figure 8, it was possible to note the similarity of the fracture mechanisms after the three-and five-pass HR processing. It could be assumed that a further increase in the number of passes would result in embrittlement of the steel and a decrease in its toughness [47].…”