http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
제태진(T. J. Je),최두선(D. S. Choi),이응숙(E. S. Lee),황경현(K. H. Hwang),홍성민(S. M. Hong),최진성(J. S. Choi),송병준(B. J. Song) 한국정밀공학회 2006 한국정밀공학회 학술발표대회 논문집 Vol.2006 No.5월
As the Mobile and Display technology are being developed quickly, new wireless devices are released in great numbers. They reduce existing devices’ life time and demand a reduction of developing period of portable devices. With these demands, existing film cutting mold used many films of portable devices, especially LCD Display, needs to be more precise, and cheaper. In this research, we have analyzed machining characteristics of cutter shapes, materials, and cutting conditions for application to other films. Cutter edge was machined by slot cutting method and CAD program to select the cutter shape and cutter angle. Also, we have determined the optimal cutting conditions using high speed machining experiments to improve the productivity.
10Cr-MoVNbN 강의 질소함량증가에 따른 미세조직과 기계적 특성
김성호,송병준,조성석,류우석 대한금속재료학회(대한금속학회) 2000 대한금속·재료학회지 Vol.38 No.8
Microstructure and mechanical properties of 10Cr-MoVNbN steels with increasing nitrogen contents were investigated. The nitrogen contents of the steels were 0.025 wt%(N02) and 0.045 wt%(N05), respectively. After tempering, the microstructure of the steels consisted of the tempered martensite matrix and various precipitates(M_(23)C_6, Nb(C, N), Cr₂N, V(C, N)). V-rich fine precipitates(5-20 ㎚) observed in the N05 steel hindered the movement of dislocation and consequently delayed formation of subgrain during tempering. It is clarified by transmission electron microscopy that Cr₂N nitride starts to precipitate at a lower tempering temperature and to decompose at a higher tempering temperature in the N05 steel than in the N02 steel. With increasing nitrogen content, hardness, tensile strength, high temperature creep strength and creep rupture elongation increased, but impact property and minimum creep rate decreased.
10%Cr 마르텐사이트 강의 크리프 변형 중 미세조직 변화
김성호,유우석,송병준 대한금속재료학회(대한금속학회) 2001 대한금속·재료학회지 Vol.39 No.4
The relationship between creep deformation and microstructural changes in martensitic 10Cr-MoW steel has been studied. Transmission electron microscopy and image analyser were used to determine the variation of precipitates and martensite lath width size during creep deformation and aging. As precipitates are coarsened during creep deformation, dislocations become easy to move and the recovery proceeds rapidly. This leads to the growth of lath width. The average size of precipitates was linearly increased with creep time. On the other hand the growth rate of lath width is constant until tertiary creep, but the growth of lath width is accelerated during tertiary creep. It has been concluded that the growth behavior of lath width are consistent with creep deformation. Because the growth of lath width is controlled by the coarsening of precipitates it is important to form more stable precipitates in creep condition for improvement of creep properties of martensitic steel. Microstructure of martensitic steel is thermally very stable, so the size of precipitates and martensite lath width are hardly changed during aging.
원자력용 HT9 강과 HT9M 강의 미세조직과 기계적 특성 변화
김성호,박순동,류우석,국일현,송병준 대한금속재료학회(대한금속학회) 1999 대한금속·재료학회지 Vol.37 No.12
Microstructure and mechanical properties of HT9 and HT9M steels for liquid metal reactor(LMR) core materials have been investigated. The tempering temperature at which cell structure was formed by rearrangement of dislocations was same in two steels. More carbides were precipitated in HT9 steel due to high carbon content and precipitation of carbides was delayed in HT9M steel. Thus the decrease of hardness with tempering temperature in HT9M steel was lower than that of HT9 steel. The yield strength was decreased, the fine prior austenite grain was formed, and the formation of δ-ferrite was restricted in HT9M steel by decreasing the Cr and carbon content and increasing the Nb content. Thus the impact property of HT9M steel was improved.
12Cr-1MoVW 강의 열처리에 따른 탄화물의 화학조성 변화
김성호,유우석,국일현,송병준 대한금속재료학회(대한금속학회) 2000 대한금속·재료학회지 Vol.38 No.3
Dissolution and precipitation reactions of the carbides occurred during heat treatment of 12Cr-1MoVW steel were studied. Transmission electron microscopy and energy dispersive X-ray spectroscopy were used to determine types and chemical compositions of precipitates. The dissolution of the M_(23)C_6 carbide took place during normalizing treatment through the diffusion of chromium atoms. Upon tempering, types of M₃C and M_(23)C_6 precipitates were formed depending on the tempering conditions. The chemical composition of M₃C formed at low tempering temperature is similar to the base material, but the enrichment of chromium and depletion of iron in M₃C occur with increasing the tempering time and temperature. On the other hand chromium content decreases and iron content increases in M_(23)C_6 carbide with increasing the tempering temperature. M_(23)C_6 forms at the δ-ferrite/tempered martensite interface regardless of tempering temperatures. The chromium content of M_(23)C_6 formed at low temperature is low, but chromium content increases and iron content decrease in M_(23)C_6 with increasing the tempering time and temperature.