Variation in Microstrutures and Mechanical Properties During Long-term Material Degradation of Austenitic 316L Steel

In this study, we investigate the variation in microstruture and mechanical property of austenitic 316L stainless steel during long-term material degradation. To simulate the material degradation, the AISI 316 steel was exposed to accelerate under a temperature of 600℃ for up to 10000 hours at each predetermined heat treatment time. As the long-term material degradation time increase, the grain shape was changed from polygonal grains with annealing twins to circular grains. Most twins distributed uniformly interior of grains are recovered and disappered with long-term material degradation. Also, the δ ferrite along grain boundaries decomposed and transformed into the σ phase resulting in decrease of elongation of austenitic 316L stainless steel.

오스테나이트계 316강의 장시간 재료 열화에 따른 미세조직의 변화와 기계적 특성의 변화