Synchrotron-Based Experimental Investigations and Numerical Modeling of the Kinetics of Phase Transformations in the Heat Affected Zone of Welds

Lawrence Livermore National Laboratory

关键词: Welding;    Carbon Steels;    X-Ray Diffraction;    36 Materials Science;    Phase Transformations;   

DOI  :  10.2172/792799
RP-ID  :  UCRL-ID-138920
RP-ID  :  W-7405-Eng-48
RP-ID  :  792799

美国|英语

来源: UNT Digital Library

【 摘 要 】

Spatially Resolved X-Ray Diffraction (SRXRD) and Time Resolved X-Ray Diffraction (TRXRD) methods are being developed at LLNL for in-situ investigations of phase transformations in the heat-affected zone (HAZ) of welds. In this region of the weld, severe temperature gradients, high peak temperatures and rapid thermal fluctuations occur as the heat source passes through the material. These non-isothermal temperature fluctuations produce HAZ microstructures that cannot be predicted by conventional methods. The unique synchrotron-based experiments being developed here will enable the determination of phase transformation kinetics under true non-isothermal welding conditions, and can be used to aid in the development of models to predict HAZ microstructural evolution under a wide range of welding conditions. Commercially pure titanium, stainless steel alloys and plain carbon steels are currently under investigation.