피로 손상된 제진합금의 기계적 특성 및 감쇠능에 미치는 응력의 영향

Abstract

This study was carried out to investigate the effect of fatigue stress magnitude on the tensile properties of the damaged Fe–22Mn–12Cr–3Ni–2Si–4Co damping alloy under various fatigue stress magnitudes. αʹ and ε -martensite were formed by fatigue stress in the Fe – 22Mn – 12Cr – 3Ni – 2Si - 4Co damping alloy. The αʹ and ε -martensite formed by fatigue stress in the fatigue damaged damping alloy was formed with a specific direction and surface relief, or crossing each other. With an increasing magnitude of fatigue stress, the volume fraction of αʹ-martensite and ε-martensite was increased, and the increasing rate of volume fraction of αʹ-martensite was more rapid than ε-martensite. At the same fatigue stress magnitude, a large amount of αʹ -martensite was formed than ε-martensite. With the increasing of fatigue stress magnitude, the tensile strength slowly increased and elongation rapidly decreased, and then tensile strength slowly decreased by increasing the volume fraction of αʹ-martensite. The tensile properties of the damaged Fe – 22Mn – 12Cr – 3Ni – 2Si – 4Co alloy under fatigue stress were strongly affected by the αʹ -martensite formed by fatigue stress. This results were the same tendency for metal with the strain induced martensite transformation.