Pj. Qiu et M. Nagumo, Effect of austenitizing temperature on intergranular proeutectoid ferrite nucleation in a V-N steel, TETSU HAGAN, 85(1), 1999, pp. 45-51
Citations number
19
Categorie Soggetti
Metallurgy
Journal title
TETSU TO HAGANE-JOURNAL OF THE IRON AND STEEL INSTITUTE OF JAPAN
Intergranular proeutectoid ferrite nucleation in a V-N steel has been exami
ned at isothermal transformation at 600 degrees C with respect to the auste
nitizing temperatures. While substantial grain growth takes place, the numb
er of intergranular ferrite grains per unit grain boundary area decreases w
ith increasing austenitizing temperatures. Non-stationary increasing rate w
ith time is observed. Overall transformation during isothermal transformati
on delays after austenitizing at higher temperatures and follows the Johnso
n-Mehl-Avrami formula for the case of fast grain boundary nucleation. It is
discussed that the decrease in the intergranular ferrite nucleation rate a
ssociated with higher austenitizing temperatures is partially due to grain
boundary structures, not merely to the decrease in the nucleation sites ass
ociated with grain growth. Use of high austenitizing temperature is requisi
te for the intragranular ferrite precipitation.