Resumen en Inglés:

Abstract Residual stress evaluation in welded joints is of major importance, since its underestimation or lack of control can lead to deformations of welded components, to its mechanical properties’ deterioration or even to failure in service. Various destructive and non-destructive techniques exist for measuring residual stress, each differing in complexity, cost, and accuracy. This study investigates the applicability of the hole-drilling method combined with Electronic Speckle Pattern Interferometry (ESPI) for residual stress evaluation specifically in welded joints, where surface conditions and material properties differ from the base metal due to reinforcement convexity, surface irregularities, and microstructural changes. The methodology involved initial equipment calibration using known strain levels, followed by residual stress measurements on bead-on-plate samples — produced with and without filler material. The analysis focused on different weld regions (fusion zone, heat-affected zone, and base metal), considering both longitudinal and transverse stress components. Calibration results showed a mean measurement error of 5.8% and a coefficient of variation around 6%. For the welded beads, the ESPI-based hole-drilling method demonstrated coherent residual stress distributions consistent with theoretical models. Higher precision was observed for the transverse stress component and in samples welded without filler material, while the longitudinal stresses in the heat-affected zone of the welds with filler addition exhibited greater variability due to local metallurgical and geometrical effects. Overall, the study confirms that the combined hole-drilling and ESPI technique is a viable and reliable approach for residual stress measurement in welded joints, provided that factors such as measurement depth, surface condition, and local stress gradients are carefully managed.

Resumen en Inglés:

Abstract This work presents a comparison between the Remote Field Testing (RFT) and Internal Rotary Inspection System (IRIS) non-destructive testing (NDT) techniques. Such a comparison aims to assess the influence of the inspector experience on the RFT inspection process, as well as to evaluate whether the RFT technique has an inspection capability equivalent to the IRIS test. By using inspection data, a statistical analysis was conducted based on the results from three different RFT inspectors. Then, considering a third technique (3D Scanning) applied to sections extracted from tubes (destructive case) as a reference basis, the statistical equivalence of both NDT techniques was evaluated. Finally, to assess the accuracy of the analyses conducted by the RFT inspectors and the comparison between the RFT and IRIS techniques, artificial intelligence (AI) tools were employed to measure the success and error rates of corrosion detection via the RFT case. The results show equivalence between the NDT techniques and, despite the interpretation challenges with the RFT case, the subjectivity by the inspectors with its inspection process was considered low. The AI classification results indicated that the generated network was capable of classifying the corrosion effectively, hence supporting the equivalence between the RFT and IRIS techniques.

Resumen en Inglés:

Abstract The understanding of the corrosion mechanisms of magnesium-based alloys is crucial for their utilisation in lightweight engineering, due to their minimal corrosion resistance preventing its widespread application. In this investigation to improve the hardness, corrosive and wear behaviour of a AZ31 by its incorporation of Tungsten Carbide (WC) ceramic reinforcement and wear behaviour with varying levels of reinforcement (2.5, 5.0 and 7.5 wt.%) weight percentage. The alloy and composites were manufactured via liquid metallurgy The microstructure analysis, XRD, hardness, salt spray corrosion analysis varying (2.5 -5.0%) Nacl solutions and dry sliding wear behavior were evaluated using pin-on-disc tests under loads of 10–60 N. The results indicates that fine distribution of reinforcement and free from casting defects through SEM and presence of particles is confirmed with EDS and XRD analysis. The improved hardness up to 78.5% on AZ7.5 as compared to all fabricated samples. The formation of stable Mg (OH)2 as protective layer on AZ5.0 shows a better corrosion resistance in all NaCl conditions. The improved wear resistance on AZ7.5 is attributed to the development of a tribolayer, it improves the resistance to applied load. The SEM micrograph reveals the plastic deformation observed in AZ0 and the mild wear behaviour exhibited by the AZ7.5 composite.