Development of a New Laboratory Test Method for Spring Steels

Abstract

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.

Effect of Boron on Mechanical Properties and Fatigue Life of Spring Steel for Automobile Suspension

“…The tensile tests of heat-treated samples at room temperature were under the international standards ISO 6892-1:2009. The elastic sag resistance of spring steel was tested by torsional Bauschinger method [21]. The heat-treated wire rods were made into standard torsion samples following ISO 18338:2015, the samples were twisted to 35 ° at 10 °/min and released to 0 °, then twisted again to 35 ° at 10 °/min in the same direction.…”