This paper presents a study of the tensile properties of austenitic high-manganese steel specimens with different grain sizes. Although the stacking fault energy, calculated using a modified thermodynamic model, slightly decreased with increasing grain size, it was found to vary in a range of 23.4 mJ/m2 to 27.1 mJ/m2. Room-temperature tensile test results indicated that the yield and tensile strengths increased; the ductility also improved as the grain size decreased. The increase in the yield and tensile strengths was primarily attributed to the occurrence of mechanical twinning, as well as to the grain refinement effect. On the other hand, the improvement of the ductility is because the formation of deformation-induced martensite is suppressed in the high-manganese steel specimen with small grain size during tensile testing. The deformationinduced martensite transformation resulting from the increased grain size can be explained by the decrease in stacking fault energy or in shear stress required to generate deformation-induced martensite transformation.

1. 서 론
 2. 실험 방법
 3. 결과 및 고찰
  3.1 적층결함 에너지 및 미세조직
  3.2 오스테나이트 결정립 크기에 따른 인장 특성
 4. 결 론
 Acknowledgements
 References

• 이상인(서울과학기술대학교 신소재공학과) | Sang-In Lee
• 조윤(서울과학기술대학교 신소재공학과) | Yun Cho
• 황병철(서울과학기술대학교 신소재공학과) | Byoungchul Hwang