Original scientific paper
The Effect of PWHT on Electrochemical Behaviour of AISI 316L Weld Metal
S. Kožuh
; Faculty of Metallurgy, University of Zagreb, Aleja narodnih heroja 3, 44103 Sisak, Croatia
M. Gojić
; Faculty of Metallurgy, University of Zagreb, Aleja narodnih heroja 3, 44103 Sisak, Croatia
M. Kraljić Roković
; Faculty of Chemical Engineering and Technology, University of Zagreb, Savska cesta 16/I, 10000 Zagreb, Croatia
Abstract
The subject of investigation was the corrosion behaviour of AISI 316L austenitic stainless steel weld metal as dependent on a protective passive film formed on the steel surface following exposure to w = 3.5 % NaCl. The corrosion properties were examined before PWHT and after it by means of cyclic polarization, electrochemical impedance spectroscopy, and chronoamperometric measurements. Cyclic polarization curves clearly indicated a decrease in the pitting potential following PWHT. Passivity was observed over a broad potential region. Charge transfer resistance associated with the corrosion resistance of the passive film as determined by electrochemical impedance spectroscopy
indicated that high temperature PWHT acted by increasing the thickness of the passive film.
Keywords
Austenitic stainless steel; weld metal; microstructure; pitting corrosion; passive film
Hrčak ID:
30657
URI
Publication date:
23.12.2008.
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