Effect of Cold Working on Austenite Grain Coarsening Temperature in Low Alloy Steels

Abstract

The effect of cold working on the austenite grain coarsening temperature has been investigated by the use of low carbon chromium molybdenum steels and the result has been discussed in terms of the particle size of aluminum nitride and the initial grain size of austenite.
It is indicated that the austenite grain coarsening temperature decreases with an increase of the reduction of cold rolling and increases by an annealing treatment subsequent to cold rolling in the temperature range of 500 to 700°C.
There is no significant difference between the particle size of aluminum nitride precipitated in austenite of the cold rolled steel and that of the steel not rolled.
The initial grain size of austenite decreases with an increase of cold reduction and increases by annealing at 700°C after cold rolling. It can thus be concluded that the depressed austenite grain coarsening temperature for the cold steel results from finer initial grain size of austenite formed from the deformed ferritecarbide aggregates.