酸化鐵의 還元과 浸炭의 相互關係에 關한 硏究 = (A)Study on the correlation between reduction and carburization in iron oxide

다국어 초록 (Multilingual Abstract)

The carburization process was accomplished at the reduced iron layers. The experiments were carried out for the purpose of studying the relationship between reduction and carburization. The mechanism of carburization was studied for the iron oxide and the pure iron. The results obtained were as follows;
1. As the iron oxide was reduced by carbon series, the dense iron layer was produced at the initial stage and the porous iron was produced by the burst of dense iron layer at the following stages.
2. The morphology of the porous iron at the interface of iron and wustite were divided into three types as the wustite was reduced by the mixture of gas, such as CO-CO₂, CO-N₂.
Type A: Longitudinal regular growth, planar interface.
Type B: Longitudinal regular growth, irregular interface.
Type C: Irregular growth, irregular interface.
3. The pore size of porous iron was controlled by the following factors as the wustite was reduced by the mixture of gas as CO-CO₂, CO-N₂.
The composition of gas
The reduction temperature
The component and structure of dense iron layer
The sintering and reduction time of iron layer
The morphology of porous iron.
4. The carburization of iron oxide by CO gas was accomplished with the reduction process simultaneously, and the carburization of iron oxide by solid carbon was carried out at the finish of reduction reaction.
5. As the iron oxide was reduced and carburized by CO gas about 1300℃, the surface was melted by the depression of melting point at the iron oxide layer and the reduction process was interrupted by the melting surface of iron oxide, In this process, the solid carbon was the main mechanism of carburization.
6. The main carburization mechanism of pure iron ingot and the sintered iron powder were proceeded by CO gas at 1100℃ below, solid carbon at 1300℃ above, respectively.
7. The main carburization mechanism of pure iron ingot at 1200℃ was proceeded by solid carbon, and sintered iron powder was proceeded by CO gas, however, in case the reduction time was above 5 hours, the carburization was proceeded by solid carbon.
8. As the pure iron ingot was carburized, the effective diffusion coefficient D_eff of carbon were;
① D_eff=0.211x10^-6 cm^2 sec^-1 at 1200℃
D_eff=0.391x10^-6 cm^2 sec^-1 at 1300℃
in the atmosphere of N2 gas
② D_eff=0.599x10^-6 cm^2 sec^-1 at 1100℃
D_eff=0.237x10^-6 cm^2 sec^-1 at 1200℃
D_eff=0.087x10^-6 cm^2 sec^-1 at 1300℃
in the atmosphere of CO gas.
9. As the sintered iron powder was carburized, the effective diffusion coefficient D_eff of carbon were;
① D_eff=0.157x10^-6 cm^2 sec^-1 at 1200℃
D_eff=0.103x10^-6 cm^2 sec^-1 at 1200℃
in the atmosphere of N2 gas
② D_eff=0.124cm2sec-1 at 1100℃
D_eff=0.102cm2sec-1 at 1200℃
D_eff=0.408x10^-6 cm^2 sec^-1 at 1300℃
in the atmosphere of CO gas.

목차 (Table of Contents)

• 목차
• 第1章 總論 = 1
• 第2章 酸化鐵의 還元機構 = 4
• 2-1 緖言 = 4
• 2-2 試料 및 實驗方法 = 5
• 2-2-1 試料 = 5
• 2-2-2 還元實驗 方法 = 7
• 2-3 實驗結果 및 考察 = 9
• 2-3-1 CO濃度變化와 還元 = 9
• 2-3-2 反應溫度 및 反應時間 變化와 還元 = 15
• 2-3-3 還元形態 = 21
• 2-4 結論 = 26
• 第3章 酸化鐵의 還元과 浸炭 = 28
• 3-1 緖言 = 28
• 3-2 試料 및 實驗方法 = 30
• 3-2-1 試料 = 30
• (1) FeO試料 = 30
• (2) Fe₃O₄試料 = 31
• (3) Fe₂O₃試料 = 32
• 3-2-2 還元 및 浸炭實驗 = 32
• (1) FeO의 還元 및 浸炭實驗 = 32
• (2) Fe₃O₄의 還元 및 浸炭實驗 = 34
• (3) Fe₂O₃의 還元 및 浸炭實驗 = 34
• 3-3 實驗結果 및 考察 = 35
• 3-3-1 FeO의 還元 및 浸炭 = 35
• 3-3-2 Fe₃O₄의 還元 및 浸炭 = 47
• 3-3-3 Fe₂O₃의 還元 및 浸炭 = 49
• 3-4 結論 = 55
• 第4章 純鐵의 浸炭 = 56
• 4-1 緖言 = 56
• 4-2 試料 및 實驗方法 = 57
• 4-2-1 試料 = 57
• 4-2-2 純鐵의 浸炭實驗 = 57
• (1) 純鐵잉고트의 浸炭實驗 = 57
• (2) 燒結된 粉鐵의 浸炭實驗 = 59
• 4-3 實驗結果 및 考察 = 59
• 4-3-1 純鐵 잉고트의 浸炭機構 = 59
• (1) 固體炭素에 의한 浸炭 = 59
• (2) CO가스에 의한 浸炭 = 62
• 4-3-2 燒結된 粉鐵의 浸炭機構 = 67
• (1) 固體炭素에 의한 浸炭 = 67
• (2) CO가스에 의한 浸炭 = 75
• 4-3-3 速度論的 考察 = 83
• 4-4 結論 = 88
• 第5章 總括 = 89
• References = 92
• Summary = 97