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Corrosion behavior of Ti–6Al–4V alloy weldment in hydrochloric acid
Author(s) -
Atapour M.,
Fathi M. H.,
Shamanian M.
Publication year - 2012
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.201005821
Subject(s) - corrosion , materials science , hydrochloric acid , metallurgy , alloy , dielectric spectroscopy , microstructure , tungsten , welding , acicular , base metal , metal , electrochemistry , electrode , chemistry
The corrosion behavior of a thin sheet of Ti–6Al–4V alloy was investigated in hydrochloric acid solution after welding by gas tungsten arc welding. The resulting microstructure of the weld metal (WM) consisted of coarse prior β grains containing fine acicular α platelets. It was found that both base metal (BM) and WM exhibited active–passive behavior after surface activation in open circuit potential experiments. The corrosion resistance of the BM and WM was found to decrease with increasing the temperature and acid concentration. However, the WM exhibited higher corrosion rate than the BM in all examined conditions. These results were also corroborated by electrochemical impedance spectroscopy measurements. Furthermore, it was revealed that the activation energy of the corrosion process for the WM was lower as compared to the BM, which confirmed the inferior corrosion behavior of the WM.