The Deformation and Ageing of Mild Steel

Mild steel deforms by a series of bands of plastic deformation called Lüders bands. In heavy tensile specimen a complexs series of bands may arise, but in thin wire specimens it is shown that only single bands are formed. Measurements have been made of the propagation stress and Lüders strain for these single bands, and the effects which occur on ageing deformed specimens have been studied. A critical examination of current theories of the upper yield point - the stress at which bands first appear - is also undertaken