Abstract
Pollution is a problem that affects us, and every day is more necessary to take into account the reduction of emission to environment. One of the proposal to reduce the pollution is decreasing the weight of automobiles. To reach this objective, it is necessary to develop new materials much lighter than the materials actually used in the relevant applications.
This project focuses on a steel which composition corresponds to a Fe-Mn-Al-C system. It is lightweight steel, which has been developed for application in the automotive industry with the main objective of reducing the weight of vehicles. The reduced weight of vehicles will result in lower carbon emissions.
The project focuses on the microstructural design in the material using heat treatments (varying temperatures and time). The range of solution treatment temperatures used in the preliminary study goes from 900 ºC to 1200 ºC, being the best result obtained from the solution heat treatment at 1000 ºC for 30 min. The range of temperatures of the aging treatment goes from 400 ºC to 650 ºC, with a range of time from 5 min to 8h. The optimum aging temperature is found to be 550 ºC, because at this temperature, the dispersed k-nanocarbides are formed, since the κ-carbides require the diffusion of carbon and aluminium to form in austenitic microstructure.
The material is characterized by different experimental techniques: hardness test, tensile test, SEM microscopy, TEM microscopy and EBSD analysis. The analysis of the obtained experimental results allows to determine the most optimum heat treatment parameters leading to promising microstructures, which show improved hardness and mechanical performance.