Effect of cold rolling and annealing on the grain refinement of low alloy steel

Abstract

A low alloy steel containing 0.06 wt% C, 1.5 wt% Mn and 0.1 wt% V was given 85% cold rolling reduction. The aim of the rolling reduction was to induce energy due to stresses and distribution of carbides, used for grain refinement in subsequent annealing. The rolled specimens were heat treated at various temperatures from 590°C to 650°C for different lengths of soaking times ranging from five minutes to two hours, to promote the process of re-crystallization. At temperatures with long soaking times the re-crystallization process is expected to be completed with minimum of grain coarsening due to carbide distribution, especially vanadium carbides. A smooth drop in hardness with increase in annealing times was observed which may be due to recovery from stressed conditions during process of re-crystallization. Texture observations supported the re-crystallization process as the preferred orientation of (200) plane in rolled condition was successively reduced with annealing temperatures. Tensile properties observations of two hour annealing times at 590°C to 650°C clearly demonstrated that ductility increased at all annealing temperatures with maximum gain at 625°C and strength is decreased. © Published under licence by IOP Publishing Ltd.