A new path forward for understanding microstructural evolution during welding

作者：Elmer John W^*

来源：Welding Journal, 2008, 87(6): 149S-166S.

• HAZ formations
• in-situ experiments
• microstructure evolution
• phase transformations
• real time observations
• synchrotron radiation
• solidification mode
• X-ray diffraction

Over the past century, the principal method for estimating the sequence of microstructural events that produce the final weld microstructure has been postweld microstructure analysis, and it's the interpretation of these microstructures that sets welding metallurgy apart from other related endeavors. In conjunction with heat flow analysis and thermodynamic principles, the postweld microstructural interpretation of grain sizes and shapes, seeond-phase particles, interphase boundaries, and composition gradients provide the framework for interpreting the events that lead to the final microstructure. However, without direct and confirming evidence of the actual phases that exist during welding, multiple interpretations for microstructural evolution of welds often occur. For this reason, methods for the direct observation of the phases and phase transformations that occur during welding was developed. This paper summarizes the 2007 Adams Lecture titled "A New Path for Understanding Microstructural Evolution during Welding Using Synchrotron Radiation," where real-time X-ray diffraction methods were presented as a means for the direct observation of phase transformations during welding.

• 出版日期2008-6