Abstract
The effect of austenitizing temperature and Cr, Mo and Mn addition on microstructure and mechanical properties of V microalloyed medium carbon steel has been studied by means of metallography and mechanical testing. The addition of Cr, Mn and Mo leads to a decrease in yield strength (YS) by approximate 100 MPa in comparison to the base steel. It is assumed that Mn and Mo increase hardenability by promoting the formation of bainitic sheaves (BS), i:e: by suppressing the formation of ferrite-pearlite and acicular ferrite (FP-AF). Cr at the level used in this work is not that e®ective. Presence and packet size of bainitic sheaves decrease the Charpy V-notch impact energy at 20 ±C (CVN20) in comparison to ferrite-pearlite and acicular ferrite microstructures.