@inproceedings{paperid:1018314,
author = {M. Golyani and Moayed, Mohammad Hadi and A. Davoodi},
title = {Weldment corrosion characterization of multi-pass hybrid GTAW-SMAW 2205 duplex stainless steel in 3.5%NaCl solution},
booktitle = {ششمین سمینار الکتروشیمی ایران},
year = {2010},
location = {IRAN},
keywords = {2205 alloy is an austenitic-ferritic stainless steel with superior corrosion resistance
encompassing numerous applications in marine environments and petroleum
industrials. Nevertheless; welding operation changes the microstructure; austeniteferrite
(γ/) ratio and also causes precipitation of various phases such as σ; α´; χ; etc.
which certainly have remarkable influence on alloy corrosion resistance. In this study;
single root-pass gas tungsten arc welding (GTAW) followed by multi-pass shielded
metal arc welding (SMAW) operations were performed on a V-shape weld groove. Nirich
filler electrodes of grade ER2209 and E2209 was used; respectively; for GTAW and
SMAW operations. Corrosion behavior of GTAW; SMAW; inter-passes; cover-pass
regions and corresponding HAZ (heat affected zone) were carefully examined in 3.5%
NaCl solution by several DC electrochemical techniques including open circuit potential
(OCP); potentiodynamic polarization (PD); potentiostatic polarization (PS) and Zero
resistance ammetery (ZRA) tests. OCP values could be sorted on descent as base
metal; GTAW; cover pass SMAW; HAZ; and inter-passes SMAW. PD tests
demonstrated that passivity range; passivation potential (Epass) and current density
(Ipass) related to GTAW; cover-pass SMAW were almost similar to the base metal. Other
regions showed inferior passivation behavior. However; all regions represent
transpassivity behavior and no pitting could be observed in a large anodic PD. The PS
tests in 200; 500 and 700 mV anodic potentials showed that in all of regions Ipass was
stable and increases from GTAW; base to SMAW regions. Galvanic corrosion rate
measured by ZRA after 150 hours for three possible couples; base-SMAW; base-GTAW
and base-HAZ; revealed that current densities of three couples were negligible with
highest current density of 250 nA.cm-2; associated to the base-HAZ couple; confirming
the OCP results in which the largest driving force (OCP difference) was measured
between this couple. In summary; from corrosion resistance point of view; the
performed welding operation was satisfactorily.},
}