Corrosion Studies on Post-Weld Heat Treated Dissimilar AISI2205 and AISI310 Joints Using Electrochemical Noise Analysis

The corrosion behavior of dissimilar weldments between AISI310 and AISI2205 stainless steels in a 5 % calcium chloride solution at 50 °C was investigated under three conditions: as-welded, lower post-weld heat treatment at 800 °C, and higher post-weld heat treatment at 1000 °C. Microstructural examination revealed severe pitting in the as-welded sample, with pit widths ranging from 270 μm to 360 μm. The lower heat-treated sample had larger pits (310 μm to 370 μm), while the higher heat-treated sample showed homogeneous corrosion with a protective oxide coating. The as-welded sample had the highest corrosion rate, followed by the lower heat-treated sample, which had a moderate rate, and the higher heat-treated sample had the lowest rate. The corrosion current densities were 5.26×10—³ mA/cm², 4.6×10—4 mA/cm², and 1.4×10—4 mA/cm², respectively. Electrochemical noise measurements confirmed these findings, with the higher heat-treated sample showing negligible localized corrosion and homogenous corrosion behavior.