Influencia de un tratamiento isotérmico en la resistencia al desgaste según norma ASTM G-65 en un acero AISI SAE 1045

Abstract

The ongoing progress of automotive industry on the last few years has boosted the development of new materials and as a consequence there is improvement in mechanical characteristics and resistance to fatigue, which reduce the vehicles’ weight and the fuel consumption without affecting the passengers’ safety.The dual phase steels (DP) belong to the High-strength Low-Alloy group (HSLA), which is recognized by its properties of high strength and ductility, this combination of features is related with the volumetric fraction of the micro-constituents. Several sources suggest that high strength of the martensite does not guarantee good performance to abrasion, which is generated for its fragility.The main objective of this work is to analyze the influence of the micro structure: martensite-ferrite, martensite-ferrite-bainite in resistance to abrasion of steel AISI 1045. In order to obtain the microstructure, the material was exposed to a heat treatment with intercritical temperatures of 740°C and 770°C. Then isothermal process with temperatures of 450°C and 550°C with different times of sustenance. Once the microscopic test SEM and DRX were done, the bainite and martensire fraction are attained.The resistance to abrasive fatigue of the selected steel was obtained applying the ASTM-G65. Also was found that resistance to fatigue is directly related to the microstructure. On the other hand the volumetric loss of mass was found to be 15% higher than the same material without treatment.