Kinetics of Cottrell atmosphere formation during strain aging of ultra-lowcarbon steels

A model has been developed based on Cottrell's theory to describe the forma tion of Cottrell atmosphere by taking into account the effect of the decrea se in the concentration of carbon atoms in solution, the saturation of the dislocations and the segregation of carbon atoms to grain boundaries. The s train aging of an ultra-tow carbon bake hardening steel has been investigat ed both theoretically with this model and experimentally. It is indicated t hat the model describes the formation of Cottrell atmosphere much more reas onably than Cottrell's formula does. (C) 2000 Elsevier Science B.V. All rig hts reserved.