The microstructure and mechanical characteristics of SUS630 specimens fabricated using the direct energy deposition (DED) process are investigated. In DED, several process parameters such as laser scan speed, chamber gas flow, powder carrier gas flow, and powder feed rate are kept fixed; the laser power is changed as 150 W, 180 W, and 210 W. As the laser power increases, the surface becomes smooth, the thickness uniformity improves, and the size and number of pores decreases. With the increase in laser power, the hardness deviation decreases and the average hardness increases. The microstructure of the material is columnar; pores are formed preferentially along the columnar interface. The lath-martensite phase governs the overall microstructure. The volumetric fraction of the retained austenite phase is measured to increase with the increase of laser input power.

Abstract
 1. 서 론
 2. 실험 방법
 3. 결과 및 고찰
 4. 결 론
 References

• 백성은(한밭대학교 신소재공학과) | Seong Eun Back
• 김정한(한밭대학교 신소재공학과) | Jeoung Han Kim Corresponding Author
• 노경호(LIG넥스원 유도무기1연구소) | Kyung-Ho Noh
• 박진용(LIG넥스원 유도무기1연구소) | Jin Yong Park
• 조용주(LIG넥스원 유도무기1연구소) | Yong Ju Cho