COMPARISON OF ALUMINIUM GRAIN REFINED AND VANADIUM GRAIN REFINED SPRING STEELS FOR THE MANUFACTURE OF HIGHLY STRESSED AUTOMOTIVE COIL SPRINGS

Abstract

The selection of a particular steel grade for an application is extremely important to ensure that the final components have a long serviceable life. The chemical compositions of the steels are critical, and minor changes in chemistry can make substantial differences. Aluminium and vanadium are used in heat treatable steels as grain refining agents. These elements affect the properties of the steels. Two steels with identical chemical composition except for the aluminium and vanadium additions were comparatively tested to determine the better steel for a particular automotive coil spring. The tests included mechanical testing and on site fatigue testing. Fatigue resistance is extremely important especially for automotive coil springs. The mechanical properties revealed superior tensile strength in the vanadium grain refined spring steel while the aluminium grain refined spring steel had superior ductility and fatigue resistance.