An interstitial-free ferritic stainless steel was cold-worked to a total strain of 4.6. The highly strained steel was characterized by a sub-microcrystalline structure consisting of elongated grains/subgrains with the transverse size of about 210nm; and the fraction of high-angle grain boundaries was about 0.6. Following a rapid rise at an early processing stage, the dislocation density in (sub)grain interiors unusually decreased after total strains of above 2. Nevertheless, the samples were characterized by high residual stresses that result in complex elastic distortions of the crystal lattice within the elongated crystallites. Such internal stresses were shown to be originated from deformation grain boundaries including low-angle sub-boundaries.

Internal Stresses in a 15%Cr Ferritic Stainless Steel after Large Strain Unidirectional Processing. A.Belyakov, K.Tsuzaki, R.Kaibyshev: Journal of Physics - Conference Series, 2010, 240[1], 012115