In this study, the effect of welding heat input on the microstructure and mechanical properties of reduced-activation ferritic/martensitic steel weld metal was investigated to provide a basis for developing welding technology for this steel, which is considered a structural material for fusion reactor blankets. Autogenous bead-on-plate gas tungsten arc welding was performed with heat inputs of 0.57, 1.38, and 2.32 kJ/mm, and the microstructural evolution and mechanical properties of the weld metal were analyzed. The fraction of residual δ-ferrite in the weld metal varied depending on the welding heat input, which acted as a primary factor contributing to the reduction in weld metal strength, although it remained higher than that of the base metal. In addition, the effect of post-weld heat treatment (PWHT) at 730 °C for 1 h was evaluated. Before PWHT, the weld metal exhibited significantly higher hardness compared with the base metal. However, after PWHT, its hardness was substantially reduced, thereby minimizing the differences in hardness of the weld and the base metal.

Abstract
1. 서 론
2. 실험 방법
3. 결과 및 고찰
4. 결 론
Acknowledgement
References
<저자소개>

• 김경환(한국재료연구원 원자력안전연구단) | Kyoung-Hwan Kim (Department of Nuclear Safety Research, Korea Institute of Materials Science, Changwon 51508, Republic of Korea)
• 박기태(한국재료연구원 원자력안전연구단) | Gitae Park (Department of Nuclear Safety Research, Korea Institute of Materials Science, Changwon 51508, Republic of Korea)
• 김찬규(한국재료연구원 원자력안전연구단) | Chan Kyu Kim (Department of Nuclear Safety Research, Korea Institute of Materials Science, Changwon 51508, Republic of Korea)
• 오창영(한국재료연구원 원자력안전연구단) | Chang-Young Oh (Department of Nuclear Safety Research, Korea Institute of Materials Science, Changwon 51508, Republic of Korea)
• 송상우(한국재료연구원 원자력안전연구단) | Sangwoo Song (Department of Nuclear Safety Research, Korea Institute of Materials Science, Changwon 51508, Republic of Korea)
• 강용준(한국재료연구원 원자력안전연구단) | Yongjoon Kang (Department of Nuclear Safety Research, Korea Institute of Materials Science, Changwon 51508, Republic of Korea) Corresponding author
• 이창훈(한국재료연구원 극한재료연구소) | Chang-Hoon Lee (Extreme Materials Research Institute, Korea Institute of Materials Science, Changwon 51508, Republic of Korea)