Dissociation and dissolution of cementite in low-carbon steel by cold rolling and annealing.

Abstract

Annealing processes in low-carbon aluminium-killed steel sheets after 75% cold-rolling have been studied by means of vector analyses of the thermoelectric power vs. electrical conductivity plots on the basis of the postulates, that the gradient of the vector characteristic to dislocations is 500μv•μΩ•cm•deg-1 in pure iron but decreases by trapping of carbon atoms, and that the gradient of the vector representing the cementite precipitation at 250°C is 310μV•μΩ•cm•deg-1. It is speculated that a certain amount of carbon atoms is liberated from cementite and trapped by dislocations during cold rolling. The amount, which depends on the size and morphology of cementite particles, is correlated with the kinetics of recovery and recrystallization.