| The sensitization behaviors to intergranular attack of Type 409 stainless steel have determined by chemical etching and double loop EPR test. The results of chemical etching test and double loop EPR test agreed well with each other. The degree of sensitizaton for specimens after heat-treatment at 1100℃ and 600℃ was significantly high. Then, T-T-S diagram of these annealed alloys is represented by two step "C" shape curve. Precipitates of severly sensitized specimens in grain boundries were identified as Ti(C, N) by EDS analysis. It is suggested that sensitization behavior of Type 409 stainless steel is influenced by micro-galvanic corrosion due to concentrated Ti(C, N) precipitates in grain boundaries, besides by chromium depletion. Especially, it was found that high temperature sensitization produced more Ti(C, N) precipitates than low temperature sensitization |
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