Quantification of CTOD fracture toughness in welded joints to evaluate the efficacy of vibration stress relief compared to thermal stress relief

• Published in: Materials research (São Carlos, São Paulo, Brazil) Vol. 23; no. 4; p. 1
• Main Authors: Moraes, Amauri Gomes de, Clarke, Thomas Gabriel Rosauro, Diehl, Igor Luís
• Format: Journal Article
• Language: English
• Published: Sao Carlos Universidade Federal do Sao Carlos, Departamento de Engenharia de Materiais 01-01-2020; ABM, ABC, ABPol; Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
• Subjects: Distortion; ENGINEERING, CHEMICAL; Fracture toughness; fracture toughness-ctod; Heat treating; Heat treatment; High strength low alloy steels; MATERIALS SCIENCE, MULTIDISCIPLINARY; Metal sheets; METALLURGY & METALLURGICAL ENGINEERING; Residual stress; residual stresses; Resonant mechanical vibration; Resonant vibration; Tensile tests; Thermal stress; Welded joints; x-ray diffraction; Resonant mechanical vibration; fracture toughness-ctod; x-ray diffraction; residual stresses
• ISSN: 1516-1439; 1980-5373; 1980-5373
• DOI: 10.1590/1980-5373-mr-2020-0157

Resonant vibration residual stress relief (R-VSR) is an alternative method to post-weld heat treatments (PWHT) which is said to lead to less distortion and lower costs. The method of superposition of cyclic stresses and residual stresses, which can lead to localized yielding of the material, dislocation movement and subsequent stress relief. This article aims at investigating the efficiency of resonant vibration in the relief of residual stresses in welded joints of HSLA Domex700 steel sheets. Mechanical stress relief was compared to a common PWHT, and stress levels were then quantified through X-ray diffraction. Samples were also characterized by CTOD fracture toughness tests, fractographic analysis and tensile tests. Results indicate that the mechanical method was significantly less effective in relieving stresses in comparison with the PWHT, but led to apparent improvements in fracture toughness and in tensile tests. FWHM values indicated significant distortion for PWHT and less distortion for R-VSR.