The development of accelerated corrosion test has been focused on cyclic corrosion test due to improved correlation with the field corrosion behavior. This study applied ISO 16539 to simulate the tropical coastal environment in Thailand. ISO 16539 method B with 0.1 g-salt/m<sup>2</sup> correlated well with Rayong (C2) data. A method for calculating salt deposition and testing period was derived by interpolation and extrapolation of the simulated test results that were calibrated with the field-test database for Rayong (C2) and Phangnga (C4). This work enables the application of ISO 16539 in life prediction for carbon steel exposed under tropical coastal climate with sulfur dioxide deposition rate less than 13 [mg/m<sup>2</sup>/day: mmd] and chloride ion deposition rates more than 10 mmd.

The current research was aimed to investigate atmospheric corrosion behaviors of 6005A and 6082 aluminum alloys for a certain application in high-speed railway employed for service in Thailand. Actual exposure atmospheric test with the maximum period of 18 months was conducted at urban and marine–coastal environments. After completion of actual exposure test, corrosion behaviors of the uncoated alloys were determined based on corrosion mass loss and pitting corrosion aspects. It turned out that remarkable corrosion severity found at marine–coastal environment with respect to urban environment was attributed to higher deposition rates of cumulative chloride (around 1331 mg m−2 day−1) and sulfur dioxide (around 200 mg m−2 day−1) together with higher levels of RH (>80%) for the entire year of exposure. The alloys exposed at marine–coastal environment for 18 months long revealed the corrosion mass loss of approximately 2 g m−2, average pit depth of greater than 80 μm, and density of around 3 pits⋅cm−2.

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In newly developed 2101 lean duplex stainless steel, oxide inclusions have been detected on welded metal zones after subjecting them to flux-cored arc welding with an E2209T1-1 flux-cored filler metal. These oxide inclusions directly affect mechanical properties of the welded metal. Hence, a correlation requiring validation has been proposed between oxide inclusions and mechanical impact toughness. Accordingly, this study employed scanning electron and high-resolution transmission electron microscopy to assess the correlation between oxide inclusions and mechanical impact toughness. Investigations revealed that the spherical oxide inclusions comprised a mixture of oxides in the ferrite matrix phase and were close to intragranular austenite. The oxide inclusions observed were titanium- and silicon-rich oxides with amorphous structures, MnO with a cubic structure, and TiO2 with an orthorhombic/tetragonal structure, derived from the deoxidation of the filler metal/consumable electrodes. We also observed that the type of oxide inclusions had no strong effect on absorbed energy and no crack initiation occurred near them.