http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Ti-Nb 복합 첨가강의 BH특성에 미치는 균열온도의 영향
허보영 ( Bo Young Hur ),엄용수 ( Yong Su Um ),김상열 ( Sang Youl Kim ),조상헌 ( Sang Hun Cho ),남태운 ( Tae Woon Nam ) 한국주조공학회 2004 한국주조공학회지 Vol.24 No.4
N/A Bake hardenable steel utilizes the phenomenon of strain aging to provide an increase in the yield strength of formed components. An increase of the carbon content will improve the bake hardening response: more solutes are available to pin mobile dislocations and to form the clusters more rapidly. But aging resistance decrease as increasing solute carbon. In order to under-stand the compatibility between bake hardenability and aging resistance. The optimum solute carbon control methods during manufacture should be determined. In this paper, the effect of continuous heat cycle conditions such as soaking temperature, rapid cooling start temperature, cooling rate on BH(Bake Hardenability), AI(Aging Index), YP-EI(Yield Point Elongation) and other mechanical properties have been investigated. and following results were obtained. In the case of soaking temperature, BH increases with higher soaking temperature because of NbC dissolution(830℃), Therefore the solute carbon and BH at 850℃ and 870℃ are higher than these at 810℃. But BH at 870℃ is a little lower than that at 850℃ owing to the ferrite grain size. The measurement of amount of dissolution C using IFT(Internal Friction Test) can explain the relation of solute carbon and BH.
금창훈,허보영,Keum, C.H.,Hur, B.Y. 한국재료학회 2006 한국재료학회지 Vol.16 No.5
Fluorspar has been essential flux in steelmaking process. The main effects of fluorspar addition are lowering of the viscosity and melting temperature of slag. In recent years, due to the increasing price and environmental problem of fluorspar, various types of fluorspar substitute have been investigated. In this study, iron oxide by-products such as sinter dust, basic oxygen furnace (BOF) sludge and mill scale were developed as a substitute in terms of waste recycling. Several plant trials were carried out by addition of briquetted substitutes of $4{\sim}6$ kg/ton to compare with the fluorspar of $0.7{\sim}1$ kg/ton. The substitutes showed a similar behavior of slag formation, phosphorus removal and MgO saturation content.
급냉응고와 원소첨가에 의한 Mg-Zn 합금의 미세조직 제어
김연욱,허보영 ( Yeon Wook Kim,Bo Young Hur ) 한국주조공학회 1998 한국주조공학회지 Vol.18 No.3
N/A Interest in rapid solidification of magnesium alloys stems from the fact that conventional ingot metallurgy alloys exhibit poor strength, ductility, and corrosion resistance. Such properties can be improved by microstructural refinement via rapid solidification processing. In this study, Mg-Zn alloys have been produced as continuous strips by melt overflow technique. In order to evaluate the influence of additional elements on the grain refinement and mechanical properties, Th and Zr were added in rapidly solidified Mg-5wt%Zn alloy. Then the microstructual observations were undertaken with the objective of evaluating the grain refinement as function of the cooling rate and the additional elements. The tremendous increase in hardness of Mg-Zn base alloys was mainly due to the refinement of the grain structure by the effect of rapid solidification and alloying elements. The formation of intermetallic phases on the grain boundaries may have a positive effect on the corroion resistance. Therefore, despite competition from many other developments, the rapid solidification processing of magnesium alloys emerges as a valuable method to develop superior and commercially acceptable magnesium alloys. (Received May 14, 1998)
Ar 가스 분위기에서 제조한 Mg-Zn-(Mn) 합금의 미세조직
엄정필,임수근,허보영 ( Jeong Pil Eom,Su Guen Lim,Bo Young Hur ) 한국주조공학회 1996 한국주조공학회지 Vol.16 No.4
N/A The microstructure of Mg-1∼6wt%Zn, Mg-1.5wt%Mn and Mg-3,6wt%Zn-lwt%Mn alloys were investigated by means of optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. The liquid Mg alloys were tasted into the metallic mold at room temperature, and cooling part was located at the bottom of mold. The microstructure of Mg-Zn cast alloys revealed that MgZn compounds were around the secondary dendrite arms. Scanning electron microscopy and energy dispersive spectroscopy showed that the composition of MgZn compound was Mg-77wt%Zn. The addition of Mn in Mg-Zn alloys refined the grain size in as tasted alloys. Manganese additions also increased the Vickers hardness.