표제지
ABSTRACT
목차
1. 서론 10
2. 이론적 배경 12
2.1. 침탄의 종류와 특징 12
2.1.1. 가스침탄 12
2.1.2. 진공침탄 12
2.2. 가스침탄 13
2.2.1. 가스발생로 13
2.2.2. 캐리어 가스 13
2.2.3. 입계산화 14
2.2.4. 침탄 로 내의반응 16
2.2.5. 탄소의 확산 18
2.3. 진공침탄 19
2.3.1. 진공침탄 프로세스 20
2.3.2. 침탄온도 21
2.3.3. 침탄시간 21
2.3.4. 진공침탄 가스 22
3. 실험방법 24
3.1. 시험편 24
3.2. 가스침탄 열처리 24
3.3. 진공침탄 열처리 25
3.3.1. 진공침탄 고정변수 25
3.3.2. 진공침탄의 변수 26
3.3.3. 진공 침탄의 작업공정 27
3.4. 경도 시험 28
3.5. 인장시험 29
3.6. 파단면 SEM 관찰 30
3.7. 미세조직 관찰 30
3.8. 잔류오스테나이트 량 측정 32
4. 실험결과 33
4.1. 경도 시험 33
4.2. 인장시험 및 파단면 SEM분석 결과 39
4.3. 미세조직 관찰과 EDS 분석 47
4.4. 잔류 오스테나이트 량 측정 56
5. 결론 59
참고문헌 61
감사의 글 62
Table 2.1. Propane and butane gas metamorphic composition 14
Table 3.1. Pinion shaft requirements 24
Table 3.2. The condition of vacuum carburizing 27
Table 4.1. Tensile Test Result of the SCM 415H 39
Table 4.2. Tensile test result of the carburized specimen 41
Table 4.3. Carbide EDS Element analysis 53
Table 4.4. EDS analysis of the Gas and Vacuum carburized surface 54
Table 4.5. Volume of the retained austenite 56
Fig. 2.1. Grain boundary corrosion 16
Fig. 2.2. Equilibrium diagram and carburizing basics 20
Fig. 3.1. Pinion shaft 24
Fig. 3.2. The typical gas carburizing process 25
Fig. 3.3. Relationship between carburizing time and the effective depth of hardening 26
Fig. 3.4. The typical vacuum carburizing process 27
Fig. 3.5. Micro vickers hardness tester 28
Fig. 3.6. Dimensions of Specimen 29
Fig. 3.7. Universal testing machine 29
Fig. 3.8. Low vacuum scanning electron microscope(LV-SEM) 30
FIg. 3.9. Optical microscope 31
Fig. 3.10. Energy dispersive spectrometer 31
Fig. 3.11. XRD(X-ray diffractometer) 32
Fig. 4.1. Variation of micro vickers hardness with carburizing depth(0∼1.0㎜) 33
Fig. 4.2. Variation of micro vickers hardness with carburizing depth (6.0∼7.0㎜) 34
Fig. 4.3. Variation of micro vickers hardness with carburizing depth 36
Fig. 4.4. Gas and Vac B carburizing variation of micro vickers hardness (3D graph) 37
Fig. 4.5. Tensile test graph of the SCM 415H 39
Fig. 4.6. Fractured surfaces of SCM 415H 40
Fig. 4.7. Tensile test graph of the carburized specimen 41
Fig. 4.8. Fractured surfaces of the Gas carburized specimen 43
Fig. 4.9. Fractured surfaces of the Vac-A specimen 44
Fig. 4.10. Fractured surfaces of the Vac-B specimen 45
Fig. 4.11. Fractured surfaces of the Vac-C specimen 46
Fig. 4.12. Layers of the gas and the vacuum carburizing 47
Fig. 4.13. Grain boundary corrosions of the gas and vacuum carburized 48
Fig. 4.14. Microstructure of SCM 415H 48
Fig. 4.15. Microstructures of the gas carburized specimens 49
Fig. 4.16. Microstructures of the Vac-A carburized specimens 50
Fig. 4.17. Microstructures of the Vac-B carburized specimens 51
Fig. 4.18. Microstructures of the Vac-C carburized specimens 52
Fig. 4.19. Carbide EDS measurement result 53
Fig. 4.20. Gas carburized EDS measurement result 54
Fig. 4.21. Vacuum carburized EDS measurement result 55
Fig. 4.22. X-ray diffraction of the carburized surfaces 57
Fig. 4.23. X-ray diffraction of the carburized surfaces(3D graph) 57