1 wt% Cr 첨가 페라이트계 강 내 미량 첨가된 합금원소 (C, V, Mo)가 CO2 포화 산성 수용액 내 부식 거동에 미치는 영향

Abstract

This study examined the effect of micro-alloying elements (C, V, and Mo) on the corrosion behavior of 1Cr-containing ferritic steel in a CO2-saturated acidic aqueous solution. A variety of experimental methods were employed, including microstructural analyses, electrochemical measurements, and surface examinations. The findings revealed that an increased addition of carbon (C) to this alloy system led to a higher fraction of coarse Fe C and M C , which limited chromium (Cr) enrichment in the inner corrosion scale and caused the FeCO3 crystals on the outer surface to coarsen. These changes resulted in a greater sus- ceptibility to long-term corrosion. In contrast, the addition of vanadium (V) markedly enhanced Cr enrich- ment in the inner layer and refined the FeCO3 crystals on the outer layer of the corrosion scale, leading to improved long-term corrosion resistance. Molybdenum (Mo) also contributed to enhanced corrosion resis- tance, similar to V, but during the early stages of corrosion, it exhibited much higher dissolution rates and showed a limited ability to form protective FeCO3 layers under acidic conditions, which may impede the full realization of its corrosionresistant benefits.