Abstract
The present paper describes the effect of cyclic stressing on aged microstructure in high-chromium ferritic stainless steel, Type 447. Hardness and tensile strength were largely increased by aging at 520℃ due to the 475℃ embrittlement. TEM observation revealed that the embrittlement could be attributed to the spinodal decomposition of Cr phase. Cyclic stressing during aging at 520℃ suppressed the spinodal decomposition and resulted in less hardness increase than that under static aging.
