RT info:eu-repo/semantics/article
T1 SPT analysis of hydrogen embrittlement in CrMoV welds
A1 Álvarez, G.
A1 Zafra, A.
A1 Rodríguez, C.
A1 Belzunce, J.
A1 Cuesta Segura, Isidoro Iván
K1 Hydrogen embrittlement
K1 Fracture
K1 Small punch test
K1 Weld
K1 Ingeniería mecánica
K1 Mechanical engineering
K1 Resistencia de materiales
K1 Strength of materials
K1 Ensayos (Tecnología)
K1 Testing
AB In this paper Small Punch Tests (SPT) are used to determine the mechanical properties of the heat affected zone (HAZ) of CrMoV welded joints and to evaluate the embrittlement caused by the presence of internal hydrogen. Hydrogen permeation tests were carried out to determine the effective diffusion coefficients of the different regions of welded joints, whose hydrogen contents were measured using a hydrogen analyser.The paper demonstrates that SPTs can be used to estimate the tensile properties and the toughness of small areas, such as the subzones of a welded joint which are not thick enough for machining standard specimens. In cases where it is not possible to determine the fracture toughness of brittle regions using standard SPT samples, tests using longitudinally notched SPT samples were conducted. The normalized energy at failure, , was selected as the most appropriate SPT parameter to estimate the fracture toughness regardless of the fracture behaviour of the material (ductile or brittle). It was seen that the fracture toughness of the fine grained HAZ (FG-HAZ) is similar to that of the Base Metal (BM), while the fracture toughness of the coarse grained HAZ (CG-HAZ) is more similar to that of the Weld Metal (WM). The effect of hydrogen on BM and FG-HAZ is low, with embrittlement indexes of about 20%. However, a strong effect of hydrogen was observed in CG-HAZs and WMs, with embrittlement indexes of 60–80%. and a clear change from ductile to brittle behaviour in their fracture surfaces.
PB Elsevier
SN 0167-8442
YR 2020
FD 2020-12
LK http://hdl.handle.net/10259/7374
UL http://hdl.handle.net/10259/7374
LA eng
NO The authors would like to acknowledge the Spanish Ministry of Economy and Competitiveness and the Principality of Asturias government for the financing support given to the RTI2018-096070-B-C31 and IDI/2018/000134 projects, respectively. G. Álvarez (PA-20-PF-BP19-087) and A. Zafra (PA-18-PF-BP17-038) would also thank the Principality of Asturias for the financial support through the Severo Ochoa Scholarship Programme. Finally, the authors thank the Scientific and Technical Service, University of Oviedo, for the use of the SEM JEOL-JSM5600 scanning electron microscope.
DS Repositorio Institucional de la Universidad de Burgos
RD 23-nov-2024