Prediction Model for the Microstructure and Properties in Weld Heat Affected Zone: II. Prediction Model for the Austenitization Kinetics and Austenite Grain Size Considering the Effect of Ferrite Grain Size in Fe-C-Mn Steel

Considering ferrite grain size in the base metal, the prediction model for $A_{c3}$ temperature and prior austenite grain size at just above $A_{c3}$ temperature was proposed. In order to predict $A_{c3}$ temperature, the Avrami equation was modified with the variation of ferrite grain size, and its kinetic parameters were measured from non-isothermal data during continuous heating. From calculation using a proposed model, $A_{c3}$ temperatures increased with increasing ferrite grain size and heating rate. Meanwhile, by converting the phase transformation kinetic model that predicts the ferrite grain size from austenite grain size during cooling, a prediction model for prior austenite grain size at just above the $A_{c3}$ temperature during heating was developed.

용접 열영향부 미세조직 및 재질예측 모델링: II. Fe-C-Mn 강에서 페라이트 결정립크기의 영향을 고려한 Austenitization kinetics 및 오스테나이트 결정립크기 예측모델