| 소형 원자로용 SA508 Gr.3 Cl.1 소재의 전자빔용접부 열처리에 따른 미세구조 및 기계적 특성에 대한 연구 |
정인철1,2 
, 서헌민1
, 최인성3
, 서 정3
, 조성우4
, 심덕남4
, 홍현욱2
|
1㈜한라이비텍 연구소
2창원대학교 신소재공학부
3한국기계연구원 레이저기술실용화연구실
4두산에너빌리티㈜ 원자력BG/기술연구원 |
| |
| A Study on the Microstructure and Mechanical Properties of Electron Beam Welds of SA508 Gr.3 Cl.1 steel with Different Heat Treatment conditions for Small Modular Reactor |
|
In-Chul Jung1,2
, Heon-Min Suh1
, In-Sung Choi3
, Jeong Suh3
, Seong-Woo Jo4
, Deog-Nam Shim4
, Hyun-Uk Hong2
|
1Research Institute, Halla E. B. Technology Inc., Busan, 46748, Korea
2Dept. of Materials Science and Engineering, Changwon National Univ., Changwon, 51140, Korea
3Dept. of Industrial Laser Tech., Korea Institute of Machinery and Materials, Busan, 46744, Korea
4Nuclear Power BG/R&D Institute, Doosan Enerbility Co., Ltd., Changwon, 51711, Korea |
Correspondence:
Hyun-Uk Hong,
Email: huhong@changwon.ac.kr
|
|
Received: 21 November 2023 • Revised: 16 January 2024 • Accepted: 27 February 2024 |
| Abstract |
|
Electron beam welding was conducted on SA508 Gr.3 Cl.1 steel, which is being considered as a material used in the pressure vessel steel of small modular reactors. The characteristics of the welds were analyzed under various heat treatment conditions. The heat treatment conditions were categorized as as-welded, post weld heat treatment(PWHT), quality heat treatment(QHT), and their features were examined and compared through cross-sectional structure and composition analyses, as well as mechanical property tests. The electron beam welded joints displayed no defects, including pores or cracks. weld metal of the as-welded specimen revealed a needle-type martensite with high hardness, whereas the base metal was characterized by tempered bainite. The weld cross-section bead of the QHT specimen exhibited no significant difference in microstructure compared to the base metal. Tensile testing revealed that both the as-welded and PWHT specimens fractured at the base metal, whereas the QHT specimen fractured at the weld metal. The PWHT specimens showed enhanced impact values in the welds compared to the as-welded specimens. In the QHT specimens, both the base metal and the weld metal demonstrated similarly favorable impact values, approximately 200 Joules. It is evident that post-welding heat treatment improves the toughness value, and quality heat treatment can result in the weld metal being similar to the base metal. |
| Key Words:
Electron beam welding, SA508 Gr.3 Cl.1, Small modular reactor, Quality heat treatment, Post weld heat treatment, Tempered bainite |
|
PDF Links
Full text via DOI
Download Citation
