Quantitative characterisation of substructural development during warm working of an interstitial free steel

Abstract

A Ti containing interstitial free steel was warm rolled in the temperature range 500–800°C, using wedge shaped slabs to produce a range of strains in a single rolling test. Some plane strain compression tests, under similar conditions, were carried out to obtain accurate stress–strain data. Variations in substructural features including subgrain sizes, subgrain aspect ratios, and misorientations between subgrains were quantitatively measured by TEM. Close correlation was observed between mechanical behaviour and variations in the substructure at different temperatures. At the lower temperature (500°C), the material showed cold worked characteristics, but as the deformation temperature was increased the effects of recovery became more pronounced, and hot working behaviour was obvious in the flow stress as well as in the substructural observations at 800°C.