Method and material for manufacture of rectangular wire coil springs without dynamic strain aging

摘要

Dynamic strain aging, which can result in a loss of ductility, was found to be controllable by limiting the levels of interstitials and the addition of boron. The phenomenon of dynamic strain aging and the role of interstitials as one of the root causes have been understood for decades. The present work recognized occurrence of this phenomenon in regulator springs and developed a boron-added steel to eliminate it. The results showed that dynamic strain aging in AISI 1065 grade steel occurs at a characteristic strain rate and temperature if a high level of interstitials was present. However, dynamic strain aging can be controlled by limiting the level of interstitials or by controlling its state. With the addition of boron, the free nitrogen was tied in a compound form as boron nitride. Similar effect can also be achieved by adding other elements, such as titanium.