발간논문

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Several technique shall be found for the electro-deposition of binary or ternary alloy system on the metal surfaces. In this study, by using acidic or alkaline solution, changing the concentration of solution and their external condition, the best technique for the alloy deposition was derived. In this study, the electro-deposition of Pb-Sn-Cu ternary Alloy metal was studied. Fluoborate solution was used as an acidic and cyanide-acetate solution as well as an alkaline. The hardness test and metallographic analysis were carried out for the study of mechanical properties of deposited layer and its microstructure as addition of small content of copper. As a result of this study, it is believed that Pb-Sn-Cu ternary alloy could not be electro-deposited by using alkaline solution but could be electro-deposited in an acidic solution by the addition of small amount of Cu ion, with 20-30 Vicker`s hardness. Course of Cu content, the electro-deposited layer was shown as a lamellar structure.

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Standard free energy changes for reduction of chromium oxides and formation of carbides by CO gas were calculated. The results are interpreted that reduction of chromium oxides and formation of chromium carbides from the oxides or the metal by CO gas are possible only when partial pressure of CO gas is considerably high. In this study, various ratios of CO and CO₂had been blowing through Fe-Cr alloy contained different [Cr %] and the slag at 1600℃ and the results are summarized as follows; 1. Reduction of (Cr₂O₃) to (CrO) in acid slag by CO gas was established up to about 50% CO. 2. [Cr %] in molten steel is nearly reciprocal to CO₂%, but Oxidation of chromium by CO₂is lower than the equilibrium data thermodynamically calculated, 3. Although charged chromium amount increase, chromium content in steel is constant under constant CO/CO₂ratio. 4. Carbon content in steel increases as chromium content increase.

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