Effect of temperature and strain on the formation of elongated fine grained structure in middle carbon steel during large plastic deformation

Abstract

The influence of deformation temperature and strain rate on the mechanisms of elongated fine grain (EFG) formation in the medium-carbon steel was studied. Compression tests were carried out at the temperatures in range of 673-973K at three different strain rates: 10-2, 1.3*10-3 and 10-4 s-1. Presence of two temperature intervals with different dominant mechanisms of deformation was identified: low temperature (673-823K) interval and high temperature (873-973K) interval. Microstructure evolution during deformation at strain rate of 1.3*10-3 s -1 and different temperatures was studied. Also was investigated the microstructure and mechanical properties of steel after warm plastic deformation. EFG structure formation in steel by caliber rolling at temperatures 673 and 773K on strain ∼ 1.1 results in a significant increase of toughness, including at low temperatures, while improving strength. © Published under licence by IOP Publishing Ltd.