Abstract Thermomechanical treatments and variations in chemical composition during the production of these alloys allow their properties to be adjusted as necessary. In the present research, the influence of chemical modification was analyzed by adding a combination of two rare earth elements (lanthanum and cerium) and performing a pretreatment before natural and artificial aging. With this, it was observed that said chemical modification led to an increase in hardness after artificial aging and specific suppression of the hardening speed at room temperature, combined with a pretreatment process to improve the density of the nucleation site and take advantage of the possible vacancy capture effect. Furthermore, microstructural changes were observed in the study alloys by scanning electron microscopy. The above allows the design of alloy production processes according to the requirements of each application.