This present study deals with the microstructure and tensile properties of 600 MPa-grade high strength and seismic resistant reinforcing steels. The high strength reinforcing steel (SD 600) was fabricated by Tempcore processing, while the seismic resistant reinforcing steel (SD 600S) was air-cooled after hot-rolling treatment. The microstructure analysis results showed that the SD 600 steel specimen consisted of a tempered martensite and ferrite-pearlite structure after Tempcore processing, while the SD 600S steel specimen had a fully ferrite-pearlite structure. The room-temperature tensile test results indicate that, because of the enhanced solid solution and precipitation strengthening caused by relatively higher contents of C, Mn, Si and V in the SD 600S steel specimen, this specimen, with fully ferrite-pearlite structure, had yield and tensile strengths higher than those of the SD 600 specimen. On the other hand, the hardness of the SD 600 and SD 600S steel specimens changed in different ways according to location, dependent on the microstructure, ferrite grain size, and volume fraction.

1. 서 론
 2. 실험 방법
 3. 실험 결과 및 고찰
  3.1 미세조직
  3.2 경도 특성
  3.3 인장 특성
 4. 결 론
 Acknowledgment
 References

• 서하늘(서울과학기술대학교 신소재공학과) | Ha-Neul Seo (Department of Materials Science and Engineering, Seoul National University of Science and Technology)
• 이상인(서울과학기술대학교 신소재공학과) | Sang-In Lee (Department of Materials Science and Engineering, Seoul National University of Science and Technology)
• 황병철(서울과학기술대학교 신소재공학과) | Byoungchul Hwang (Department of Materials Science and Engineering, Seoul National University of Science and Technology) Corresponding author