http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
스테인레스 전기로 슬래그 중 Cr 산화물의 환원속도에 관한 연구
김용환,양재웅,백영현,변기열 대한금속재료학회(대한금속학회) 2000 대한금속·재료학회지 Vol.38 No.4
Reduction rate of chromium oxide in slag phase was studied under an operating condition of EAF process. Synthetic CaO-SiO₂-Cr₂O₃ slag containing Al₂O₃, Fe₂O₃, or MgO were respectively prepared by sintering and pre-melting. STS 304 steel was melted in a graphite crucible under Ar-atmosphere by the high frequency induction furnace. The synthetic slag was placed on the steel melt and was reduced by carbon saturated melt. Reduction rates were measured by analyzing both steel and reacted slag sample. Microscopic analysis showed that chromium oxide in EAF slag existed largely in spinel form of FeO and MgO. Reduction yield was significantly increased by increasing temperature, and also decreasing basicity 1.5 to 1.0. The optimum temperature and basicity were found to be 1650℃ and 1.33, respectively. And the addition of Fe₂O₃ promoted the reduction rate considerably. Experimental results indicated that the reduction rate was controlled by the diffusion of chromium ion through the liquid slag phase at the initial stage of reduction and the activation energy for diffusion was found to be 129.79 kJ/㏖. It is worthy to note that reduction rate of chromium oxide increased by slag foaming at the later stage of reaction. It was also observed that SiC powder was far more effective than carbon powder as reductant at the initial stage of reaction.
용강 중의 Al 에 의한 CaO-Cr2O3 슬래그 중 Cr2O3 의 환원 속도에 관한 연구
백영현,하윤철,송효석,양재웅 대한금속재료학회(대한금속학회) 1997 대한금속·재료학회지 Vol.35 No.11
The Argon and Oxygen Decarburization (A.O.D) process is known as the most effective process for the stainless steel making. The aim of this study is to establish the reduction mechanism of Cr₂O₃, at the A.O.D reduction period. Synthetic solid slags diskes of CaO-Cr₂O₃ binary and also ternary systems containing Al₂O₃, or CaF₂ as additives were respectively prepared by compacting and sintering. AISI 304 stainless steel was melted in MgO crucible in semi-opened Ar-atmosphere at 1600-1700℃. The reduction was carried out by adding Al into molten alloy steel and then by placing the disk on it. The reduction rate was measured by analysing steel samples and also reacted slags. The reduction rate was controlled by the surface reaction and the first order with respect to the residual Al concentration. The amount of reduced Cr could be expressed by an exponential form; Δ[Cr]=2[Al]_0(1-e^(-k′(Cr₂O₃)⁴-(time))) The rate constant, k', is a function of temperature, the viscosity of slag, surface area, and surface roughness factor The activation energy obtained from these was found to be 150㎉/㏖. It is interesting to note that the reaction rate increased significantly as decreasing the viscosity of interfacial liquid slag by adding Al₂O₃, or CaF₂ to the slags.