Advances in the Control and Improvement of Quality in the Resistance Spot Welding Process

This work aims to respond to the need derived from the highly changing and competitive nature of the industrial environment in which the resistance spot welding (RSW) process is implemented, providing an updated and structured comprehensive overview of the advances that are being made in the field of quality control and the improvement of quality for this manufacturing process

Estudio mediante el Coeficiente de Máxima Información de las posibles asociaciones entre las variables de los test EPR y PAP empleados para caracterizar la corrosión por picadura en uniones de acero inoxidable AISI 304 soldadas por resistencia por puntos

En este documento se presenta un análisis de las posibles relaciones existentes entre las variables de dos de los test más empleados para estudiar la corrosión por picadura en acero inoxidable: el test de Reactivación Electroquímica Potenciocinética (Electrochemical Potentiokinetic Reactivation –ERP-test) y el test Polarización Anódica Potenciodinámica (Potentiodinamic Anodic Polarization –PAP-test). El proceso experimental consistió en la realización de ambos test sobre 242 muestras de acero inoxidable AISI 304 con uniones soldadas por resistencia por puntos (Resistance Spot Welding – RSW-). El análisis exploratorio ha sido realizado utilizando el estadístico conocido como Coeficiente de Máxima Información (Maximal Information Coefficient –MIC-), el cual es capaz de identificar relaciones bivariable tanto funcionales como no funcionales. La existencia de alguna relación entre las variables de ambos test podría permitir predecir los resultados de uno de los test a partir de los del otro, optimizando sustancialmente el tiempo y método de análisis del comportamiento de las soldaduras de acero inoxidable AISI 304 frente a la corrosión

Glass-box modeling for quality assessment of resistance spot welding joints in industrial applications

Resistance spot welding (RSW) is one of the most relevant industrial processes in diferent sectors. Key issues in RSW are process control and ex-ante and ex-post evaluation of the quality level of RSW joints. Multiple-input–single-output methods are commonly used to create predictive models of the process from the welding parameters. However, until now, the choice of a particular model has typically involved a tradeof between accuracy and interpretability. In this work, such dichotomy is overcome by using the explainable boosting machine algorithm, which obtains accuracy levels in both classifcation and prediction of the welded joint tensile shear load bearing capacity statistically as good or even better than the best algorithms in the literature, while maintaining high levels of interpretability. These characteristics allow (i) a simple diagnosis of the overall behavior of the process, and, for each individual prediction, (ii) the attribution to each of the control variables—and/ or to their potential interactions—of the result obtained. These distinctive characteristics have important implications for the optimization and control of welding processes, establishing the explainable boosting machine as one of the reference algorithms for their modeling.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. The authors acknowledge fnancial support from the Spanish Ministry of Science, Innovation and Universities (Excellence Network RED2018‐102518‐T), the Spanish State Research Agency (PID2020-118906 GB-I00/AEI/https://doi.org/10. 13039/501100011033), and the Fundación Bancaria Caixa D. Estalvis I Pensions de Barcelona, La Caixa (2020/00062/001). In addition, we acknowledge support from the Santander Supercomputación group (University of Cantabria) that provided access to the Altamira Supercomputer—located at the Institute of Physics of Cantabria (IFCACSIC) and member of the Spanish Supercomputing Network—to perform the diferent simulations/analyses

Independence of EPR and PAP tests performed on resistance spot welding joints

In the present paper, the possible relationships among the variables of the potentiodynamic anodic polarisation (PAP) test and the electrochemical potentiokinetic reactivation (EPR) test, both performed on resistance spot welding joints of AISI 304 stainless steel, are investigated. Results show that PAP variables are statistically independent from those of EPR, which implies independence between the pitting corrosion behaviour and the degree of sensitisation of the material. Parameters from PAP test are dependent among them, but this association is found noisy since the current density along the passive zone is not exactly constant. The parameters from the EPR test are confirmed as very related, presenting a linear relationship and a high coefficient of determination.Spanish Ministerio de Ciencia e Innovación (MICINN) Project CSD2010-00034 (SimulPast CONSOLIDER-INGENIO 2010)