Tohoku University · 공학
이 교수의 연구실은 저탄소 스틸의 나노미세 구조 제어를 핵심으로 하여, 나노크기의 합금 카바이드 상의 형성 거동과 그에 따른 기계적 거칠기 향상 메커니즘을 연구하고 있습니다. 특히 인터페이스 침전을 통한 강화 메커니즘, 마이크로알로이딩 요소(V, Nb, Ti)의 기여도, 그리고 3차원 원자현미경 분석(3DAP)을 활용한 나노구조 정량 분석이 주요 연구 방향입니다. FFF 3D 프린팅의 기계적 성능 향상 기술과도 연계하여, 항공우주 및 고강도 소재 응용을 위한 첨단 강재 설계 기반을 구축하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Fused filament fabrication (FFF) is increasingly adopted for direct manufacturing of end use parts in an aviation industry. However, the application of FFF technique is still restricted to manufacturing low criticality lightly loaded parts, due to poor mechanical performance. To alleviate the mechanical performance issue, thermal annealing process is frequently utilized. However, problems such as distortion issues and the need for jigs and fixtures limit the effectiveness of the thermal annealin
Abstract The current understanding of the microstructural features and mechanical properties of micro-alloyed low carbon steels strengthened by interphase precipitation of nano-sized alloy carbides are critically reviewed in this paper. The experimental results obtained via advanced quantitative characterization have revealed that interphase precipitation is promoted at the ferrite/austenite interface with a relatively lower degree of coherency caused by the deviation from the exact Kurdjumov–Sa
The resistance to temper softening in low carbon martensite with its underlying origin, by microalloying of strong carbide-forming alloying elements (V, Nb and Ti) to an Fe-0.1C-1.5Mn-0.05Si (mass%) alloy, was investigated in this study. With similar hardness in as-quenched condition in all the alloys used, the hardness of tempered martensite is increased by V, Nb and Ti additions, particularly after treatment at higher temperature with longer time. The increment in hardness becomes larger by mo
The composition of nano-sized alloy carbides formed by interphase precipitation in V-Nb and V-Ti multiple microalloyed low-carbon steels is analyzed by using three-dimensional atom probe. Carbide-forming alloying elements including V, Nb, and Ti, are simultaneously precipitated from the early stage of isothermal treatment, whose atoms are uniformly distributed in the carbide particles, even after prolonged holding. Cluster analysis by the maximum separation method, with parameters optimized usin
Interphase precipitation of nano-sized alloy carbides is recently used to strengthen low carbon steels for its excellent contributions to strength and formability. The effects of nitrogen addition on the hardness of vanadium-microalloyed low carbon steels were investigated by considering both the dispersion of interphase precipitation and the ferrite/austenite crystallography. Three-dimensional atom probe analysis reveals that interphase precipitation of vanadium carbide is hardly affected by in
The precipitation of nano-sized alloy carbides in steels with a large amount of strengthening can be obtained by conventional tempering of martensite or interphase precipitation occurring during isothermal ferrite transformation. In this study, a vanadium-microalloyed low carbon steel with a composition of Fe-0.1C-0.4V-1.5Mn-0.05Si (mass%) was either isothermally transformed or quenched and tempered at 923 K for various periods, to comparatively investigate the precipitation behaviors of vanadiu
