A Critical Evaluation of Diffraction Strain Tomography and Contour Method by Assessing Residual Elastic Strains and Quench-Induced Cracking in a Carbon Steel Bar

This study presents a critical evaluation of the contour method and synchrotron X-ray diffraction strain tomography for the reconstruction of residual elastic strains, focusing on quench-induced cracking in carbon steel components. Using the OxCM contour solver with both optical and contact profilometry, and strain tomography via the exCaking method and Rietveld refinement, the strengths and limitations of each technique are explored. High-resolution data acquisition is emphasized as essential for accurately resolving material discontinuities. The analysis also investigates the link between residual elastic strains and quench cracking, and assesses how data processing, specifically the application of a smoothness factor to capture the main features of the experimental data, affects the accuracy and reliability of contour method reconstructions.