Effect of Time and Temperature on the Sensitization on Alloy 600 by Electrochemical Potentiokinetic Reactivation |
| K. Jung, S. Kim
Mokpo National Maritime University, Division of Marine Engineering, Mokpo, Korea |
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| This study investigated the effect of temperature and time on the sensitization behavior of alloy 600. A double-loop electrochemical potentiokinetic reactivation test was conducted to evaluate the degree of sensitization (DOS) in 0.1 M H2SO4+0.001 M potassium thiocyanate solution. The microstructure and surface damages of the aged specimens were characterized by optical microscope, scanning electron microscope, and energy dispersive X-ray spectroscopy. As a result of the experiment, the sensitization behavior was significantly influenced by the expansion of the Cr-depleted zone and Cr-diffusion rate depending on the aging temperature. In particular, the alloy 600 aged for 300 h or longer at 650° represented a very low DOS value of 3% or less, and its resistance against intergranular corrosion greatly improved. |
DOI:10.12693/APhysPolA.135.999 topics: sensitization, alloy 600, electrochemical potentiokinetic reactivation, Cr-rich carbide |