Fatigue behavior analysis of railroad wheels manufactured by forging and casting process

• Grant number: 11/21347-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2012
• End date: January 31, 2013
• Field of knowledge: Engineering - Mechanical Engineering - Manufacturing Processes
• Principal Investigator: Valdir Alves Guimarães
• Grantee: Pedro Guilherme Silva Pesci
• Host Institution: Faculdade de Engenharia (FEG). Universidade Estadual Paulista (UNESP). Campus de Guaratinguetá. Guaratinguetá , SP, Brazil

Abstract

In the last centuries the development in the railroad system promoted a big technological advance, enabling a substantial growing in some areas of the engineering. In a few decades the railroads became the main vehicle, showing a continuous increase in the number of passengers and in the volume of transported load. However, this fast advance submitted the railroad components responsible for the load transport to critical levels of solicitation and, in some situations, with unknown proportions in the time. This unknowing resulted in inadequate railroad components projects and consequently a big number of accidents like fracture of axis, wheels and rails. The wheels are not new parts of the railroad industry. Since the beginning of this industry the wheels are the key components for the functioning of the railroad. For being a critical element for the security, the design and the maintenance are made with extreme care to avoid failure. Despite the railroad components be projected to support a big number of cyclical solicitation during its life, some accidents have occurred. Despite not being frequent, these accidents have major consequences, with big losses of load and life. Nowadays the railroad components failure are relatively low, for being projected to work below de Fatigue Resistance Limit of the used materials, but with the high demand for faster trains and with de raise of the load for axis need, the probability of fail occurrences grows. The proposed work includes a comparative study of two manufacture processes (forging and casting) applied in the manufacture of the railroad wheels, where will be assessed the mechanical properties of tension, fracture toughness and fatigue. The study will verify which of the mechanisms gives a better relation between life and fatigue, mechanical properties and fracture toughness. Besides of other activities, the research will include experiments to microstructure verifying, mechanical properties and material fracture. (AU)