Study of stability of strain hardening of structural materials in time

Results are given from studies in the effect of weathering time (about 5 years) between the prior plastic deformation and following loading on the deformation anisotropy of steel SP-28, aluminium alloy AMG-6 and titanium alloys VT6-S and VT14. Stability in time of hardening achieved by plastic deformation was judged from changes in the dimensions and position of the surface of loading which separates regions of elastic and inelastic strain. Changes in the parameters of the surface of loading under constant parameters of conditioned failure interface are shown to take place under weathering