Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
RESIDUAL STRESS EVALUATION IN OVERLAP JOINTS PRODUCED WITH LBW AND GTAW PROCESSES IN AISI 316L STAINLESS STEEL
Submission Author:
Olga Liskevych , ES
Co-Authors:
SHEILA DE CARVALHO, Olga Liskevych
Presenter: SHEILA DE CARVALHO
doi://10.26678/ABCM.COBEM2023.COB2023-0702
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, for example, when there is a tensile stress overlay beyond the yield stress limit. What concerns overlap type of joints, widely used in the automotive and petrochemical industries, tensile residual stress presence due to great thermal gradients and geometrical complexity of the structure may also contribute to the appearance of corrosion cracks. The objective of this study was to evaluate the residual stress distribution in overlap joints produced from stainless austenitic steel AISI 316L using different types of welding heat sources. Thus, 0.9 mm thick samples were welded with LBW and GTAW welding processes after defying the optimum parameter conditions for each procedure based on penetration efficiency and absence of defects. Subsequently, the longitudinal and transversal components of the residual stress induced by the joining procedure were measured using the ESPI-based hole-drilling method up to 0.4 mm depth at the top and root of the resultant joints. This methodology allowed the evaluation of residual stress distribution in each sample, taking into account fusion and heat effected zones, as well as base metal values. The residual stress distribution results were consistent with the theoretical models for both processes. The longitudinal component in the LBW sample showed the best repeatability of measurements and the lowest standard deviation, which may be associated to the weld geometry and heterogeneity. The tensile stress intensity was reported to be the highest in the heat effected zone of the GTAW produced sample, reaching 76% of the yield tensile strength of the AISI 316L. The difference between the residual stress at the top and at the root of the welds was reported for the GTAW produced sample and was a consequence of the partial penetration of the weld.
Keywords
residual stress, overlap joint, AISI 316L, LBW, GTAW
