질소를 첨가한 Type 316L 스테인리스 강의 동적변형시효 거동

Abstract

Tensile tests were conducted with varying strain rate (1×10^(-2)/sec∼2×10^(-4)/sec) at the test temperature range between room temperature and 750℃ to evaluate the effect of nitrogen on dynamic strain aging (DSA) behaviors in nitrogen added type 316L stainless steels. Yield and tensile strength increased without reduction of elongation with adding nitrogen. The temperature range and the critical strain for DSA increased with nitrogen addition. Types A and B serrations were observed at 600℃ and the strain for transition from type A to type B increased with nitrogen addition. Solute atoms for DSA were vacancies and chromium and the activation energy for DSA increased with adding nitrogen. The reason that nitrogen retarded DSA was explained by the fact that nitrogen reduced the chromium diffusion to dislocations due to the strong interaction between nitrogen and chromium.