A Study on Sensitization Phenomena of the Intergranular Attack
조미자Mee Cha Cho, 장승언Shung Eon Chang
Abstract
The sensitization phenomena to intergranular attack of Type 409L stainless steel containing 0.014% C and 0.0063% N has been determined by chemical etching test after subjecting the alloy to various heat treatments. Type 409L stainless steel is highly resistant to intergranular attack when 1.5㎜ thick specimens are water quenched from above 1100℃ temperature. Air cooling from temperatures between 950℃ and 1100℃, and between 500℃ and 600℃ causes to increase in intergranular corrosion comparing to the annealed base materials. Precipitates in the grain boundaries of sensitized specimens were identified as titanium nitride by STEM and EDX analysis. It is strongly suggested that the presence of such precipitates induce to develop intergranular corrosion in this alloy.