Efecto de la temperatura de recocido en una fundición gris perlítica sobre la microestructura, dureza, resistencia a la tracción y ductilidad

• Autores: Diaz Lopez, Steven Rafael, Vichez Lezama, Jhonatan Alex
• Formato: tesis de grado
• Fecha de Publicación: 2019
• Institución: Universidad Nacional de Trujillo
• Repositorio: UNITRU-Tesis
• Lenguaje: español
• OAI Identifier: oai:dspace.unitru.edu.pe:20.500.14414/12700
• Enlace del recurso: https://hdl.handle.net/20.500.14414/12700
• Nivel de acceso: acceso abierto
• Materia: Fundición gris, perlita, ferrita, grafito

In this investigation, the effect of the annealing temperature for 6 hours with slow cooling (inside the furnace) in a pearlitic gray cast iron, on the tensile strength, ductility, hardness and microstructure has been studied. Cylindrical bars with a diameter of 15 mm x 200 mm in length were used, supplied by the Metallurgical Foundry and Related Services (FUMETSA), which were annealed at temperatures of 800, 850, 900, 950 and 1000 ° C for 6 hours with slow cooling (inside the furnace), and machined for the tensile test according to ASTM E8-98 standard and for the hardness test according to ASTM E-140 standard. The results show that by increasing the annealing temperature, the tensile strength decreases from 196.00 MPa for 800 ° C to 149.70 MPa for 1000 ° C. With respect to the ductility (% elongation), this increases with the increase of the temperature of annealing from 1.80% for 800 ° C to 3.40% for 1000 ° C, and with respect to the hardness, this decreases with the increase in temperature of annealing from 133.70 HB for 800 ° C to 109.00 HB for 1000 ° C, this due to the decomposition of the austenite in ferrite and graphite in the form of flakes (Gf) that for 800 and 850 ° C the decomposition is partial, while for 900, 950 and 1000 ° C the decomposition of austenite in ferrite is total, obtaining a ferritic gray cast iron. The values of tensile strength (MPa) and ductility (%) for all levels of annealing temperature are low due to the graphite flakes (Gf) that act as a voltage concentrator. The minimum annealing temperature, in which the decomposition of austenite in ferrite is total under the study conditions, is 900 ° C and that graphite (Gf) is stable in all the processes carried out. It is concluded that the annealing temperature significantly affects the tensile strength, ductility and hardness according to the statistical analysis with 95% reliability