Development of a New Laboratory Test Method for Spring Steels

Existing methods for evaluating spring steels in terms of load-loss resistance for automotive coil spring applications are very time-consuming and require special spring-making and spring-testing equipment. Over the years, the impracticalness of these methods has been an obstacle to the development of better spring steels. The present study shows how the torsional Bauschinger test can be used to predict the relative loadloss resistance of spring steels through correlations which were worked out during the laboratory investigation. Advantages of the torsional Bauschinger test are: (a) small, straight specimens are used, (b) the test takes only a few minutes, and (c) standard equipment is employed (a standard torsion tester). Results to date indicate that this test method will serve as a practical tool for providing the kind of information needed to develop improved spring steels.