Austenite grain growth simulation considering the solute-drag effect and pinning effect.

Area of Science:

• Materials Science
• Metallurgy
• Physical Chemistry

Background:

• The pinning effect is crucial for controlling austenite grain growth in low alloy steel.
• Restraining grain growth improves heat-affected zone toughness in welded joints.

Purpose of the Study:

• To develop a novel calculation model for predicting austenite grain growth behavior.
• To integrate the solute-drag effect and the pinning effect of TiN precipitates into a unified model.

Main Methods:

• Utilized the solute-drag effect theory with assumptions of constant grain boundary width and equilibrium segregation.
• Employed Hillert's law, assuming a liquid austenite grain boundary phase for solute concentration estimation.
• Calculated equilibrium solute concentration using Thermo-Calc software and pinning effects via Nishizawa's equation.

Main Results:

• The developed model accurately predicts austenite grain growth across a temperature range of 1473-1673 K.
• Calculated austenite grain growth demonstrated excellent correspondence with experimental data.
• The model effectively integrates solute-drag and pinning effects for comprehensive prediction.

Conclusions:

• The proposed model provides a reliable method for predicting austenite grain growth in low alloy steels.
• This predictive capability is essential for optimizing heat treatment processes and improving material properties.
• The integration of solute-drag and pinning effects offers a more complete understanding of grain boundary phenomena.