In this study, two Fe-30Mn-0.2C-(1.5Al) high-manganese steels with different surface conditions were hydrogencharged under high temperature and pressure; then, tensile testing was performed at room temperature in air. The yield strength of the 30Mn-0.2C specimen increased with decreasing surface roughness(achieved via polishing), but that of the 30Mn-0.2C- 1.5Al specimen was hardly affected by the surface conditions. On the other hand, the tendency of hydrogen embrittlement of the two high-manganese steels was not sensitive to hydrogen charging or surface conditions from the standpoints of elongation and fracture behavior. Based on the EBSD analysis results, the small decrease in elongation of the charged specimens for the Fe-30Mn-0.2C-(1.5Al) high-manganese steels was attributed to the enhanced dislocation pile-up around grain boundaries, caused by hydrogen

• 이승용(서울과학기술대학교 신소재공학과) | Seung-Yong Lee
• 이상혁(서울과학기술대학교 신소재공학과) | Sang-Hyeok Lee
• 황병철(서울과학기술대학교 신소재공학과) | Byoungchul Hwang Corresponding author