Dynamic and Static Strain Aging in a High‐Manganese Steel

Abstract

Carbon‐containing high‐manganese steels are susceptible to strain aging, which influences the mechanical properties during and after deformation. To understand the strain aging behavior of austenitic Fe‐22Mn‐1.3Al‐0.3C high‐manganese steel, dynamic as well as static strain aging are examined. Dynamic strain aging, occurring during deformation, is quantified by tensile tests at different strain rates. The strain localization during straining is analyzed by digital image correlation. A decrease in strain rate increases the tensile strength and influences the onset of a serrated flow. Static strain aging is quantified by interrupted tensile tests, combined with digital image correlation and small‐angle neutron scattering (SANS). The yield strength increases due to static strain aging at room temperature within the period of days. The samples show extended yield point (yield point elongation) and the effect strengthens at higher pre‐deformation. With SANS, evidence of carbon‐manganese ordering (C–Mn ordering) during aging is obtained and correlated.