Heat-Affected Zone (HAZ) Microstructure Evolution:

Researchers delve into the phase transformations occurring in the HAZ, where the material undergoes thermal cycling but doesn’t fully melt. Subtopics include grain growth, recrystallization, and the influence of welding parameters on HAZ microstructure.

Solid-State Phase Transformations:

This subfield focuses on phase transformations that occur without reaching the molten state. Researchers explore solid-state transformations like pearlite formation, bainite development, and martensitic transformation, crucial for achieving desired mechanical properties.

Alloy-Specific Phase Change Kinetics:

Different alloys exhibit distinct phase transformation kinetics during welding. Researchers study the alloy-specific aspects of phase changes, including the nucleation and growth of different phases, to optimize welding procedures for specific materials.

Residual Stress and Distortion due to Phase Transformations:

Phase transformations induce residual stresses and distortion in weldments. Researchers in this subtopic investigate the relationship between phase changes and the resultant stresses, aiming to develop strategies for minimizing distortion and enhancing the structural integrity of weldments.

In-Situ Monitoring of Phase Transformations:

Utilizing advanced monitoring techniques, this subfield explores real-time observation of phase transformations during welding. Researchers develop in-situ methods such as acoustic emission, X-ray diffraction, and thermal imaging to gain insights into the dynamic evolution of phases in weldments.