Annealing behavior of a 304L stainless steel processed by large strain cold and warm rolling

A 304L-type austenitic stainless steel was subjected to plate rolling at ambient temperature and at 573 K to total strains of 3 and then annealed at temperatures of 873, 973 and 1073 K. The structural changes during annealing were associated with the austenite reversal (for the cold rolled samples), recrystallization and grain growth, which depended significantly on the annealing temperature. The grain growth exponent of 4 and 5 was obtained after annealing at 973 K/1073 K for the cold and warm rolled samples, whereas very sluggish grain coarsening took place at 873 K. The texture evolution during annealing in the austenite domain was characterized by gradual weakness of cold/warm rolled textures, although the main texture components such as Brass, {110}<112>, and S, {123}<634>, remained in the annealed samples irrespective of annealing mechanisms of microstructure evolution. The grain coarsening during annealing was accompanied by gradual softening. The yield strength of ultrafine grained steel processed by cold/warm rolling followed by annealing could be expressed by a Hall-Petch type relationship with σ0=160 MPa and ky=470 MPa m0.5.