Resumen

In order to improve the mechanical properties of medium carbon steels, a heat treatment of hardening is commonly achieved, improving hardness, tensile strength and wear resistance. This work focuses on studying the wear resistance of AISI 1045 steel, being tempered in automotive or machining coolants. The temples were made in discs of 3in of diameter and 5mm approximately of thickness, so that the temperature was raised to 870°C and was maintained for 50 minutes, so that a homogeneous microstructure was obtained. The cooling media used were water, Quallitor automotive coolant, and three mixtures of coolant for Solubeg machining, one of 10% coolant - 90% water, another of 30% coolant - 70% water and finally 5% coolant - 50% water. Also one of the discs was tempered in water and then tempered. The results obtained indicate that all the thermal treatments carried out reduced the coefficient of friction compared to the disc in commercial condition. But the discs tempered in water, Quallitor and the mixture of greater percentage of water, generated high losses of mass. So it is necessary to carry out a thermal treatment of tempering, which allows to reduce the loss of mass, increasing the coefficient of friction, diminishing the hardness and the residual efforts. It is identified that the relationship between hardness and coefficient of friction is indirect, but the opposite happens with the loss of mass, since the greater the hardness, this increased due to the fragility of the material. Finally, it is obtained that using a mixture of 30% Solubeg - 70% water makes it possible to obtain an intermediate hardness value, a coefficient of friction and loss of mass or rate of wear equal to or very close to that obtained by quenching in water and tempering, which indicates that it is possible to skip this thermal treatment.