THE EFFECT OF NITROGEN AND MICROALLOYING ELEMENTS (V AND V+AD ON AUSTENITE GRAIN GROWTH OF 40Cr8 STEEL

摘要

The effect of nitrogen and microalloying elements V and V+Al on austenite grain growth of steel containing 0,4 %C and 2 %Cr in austenitizing temperature range of 850-1200℃ and time range of 1 to 5h was investigated. Using a thermodynamicmodel the contents of undissolved vanadium carbonitride, V(C,N), and aluminium nitride, AIN, were calculated at austenitizingtemperatures. Using Smith-Zener equation [1] and calculated undissolved carbonitride and aluminium nitride contents as wellas austenite grain size, the mean radius, r, of precipitates was calculated. The size distributions of intercept length of austenitegrains were analysed. Strong effect of nitrogen content on austenite grain growth of microalloyed steel was observed.