표제지
목차
국문초록 7
Abstract 8
Chapter 1. 서론 (introduction) 13
1.1. 연구의 배경 및 목표 13
Chapter 2. 이론적 배경 (Background) 15
2.1. Rotary Tube Piercing 15
2.2. Mannesmann effect 19
2.3. Effect of variables 22
2.4. Rotary piercing zone 26
2.5. Homogeneous Deformation 30
2.6. Inhomogeneous Deformation 32
Chapter 3. 수치해석 기법 35
3.1. Material Modelling 35
3.2. Friction model 37
3.3. Constitutive equation 38
3.4. Theoretical external/internal diameter 42
Chapter 4. 실험 방법 45
4.1. Simulation modelling 45
4.2. Criterion of value measurement 48
Chapter 5. 실험 결과 49
5.1. Simulation condition 49
5.2. Influence of Feed angle on seamless pipe 50
5.3. Influence of Cross angle on seamless pipe 55
5.4. Influence of Roll distance on seamless pipe 62
5.5. Influence of Shoe distance on seamless pipe 69
5.6. Influence of Plug diameteter on seamless pipe 77
Chapter 6. 결론 81
참고문헌 83
Table 1. Pros and cons of guide shoes and diescher discs 16
Table 3.1. AISI 8617 material property 35
Table 3.2. Chemical composition of AISI 8617 36
Table 3.3. C-m data of AIS8617 40
Table 5.2.1. Diameter and thickness of Feed angle case 51
Table 5.2.2. Deviation and Eccentricity 54
Table 5.3.1. Diameter and thickness of Cross angle case 57
Table 5.3.2. Deviation and Eccentricity of Cross angle case 61
Table 5.4.1. Diameter and thickness of roll distance case 63
Table 5.4.2. Deviation and Eccentricity of Roll distance case 68
Table 5.5.1. Diameter and thickness of roll distance case 70
Table 5.5.2. Deviation and Eccentricity of Shoe distance at roll distance 80.0mm 73
Table 5.5.3. Deviation and Eccentricity of Shoe distance at roll distance 80.2mm 76
Table 5.6.1. Analysis data of Plug diameter and roll distance 80
Table 5.6.2. Deviation and Eccentricity of Plug diameter and roll distance 80
Fig.1. Rotary Tube Piercing process 14
Fig.2. Scheme of (a) CONE TYPE and (b) BARREL TYPE 17
Fig.3. Formation of eccenctricity and ovality 18
Fig.4. Principle of (a) damage law and (b) mannesman 21
Fig.5. Effect of plug diameter, Plug advance and feed angle on (a) diameter and (b) tool load 23
Fig.6. Effect of Feed angle, Plug diameter and roll distance in seamless pipe final diameter 24
Fig.7. Effect of Feed angle and Plug diameter in seamless pipe 25
Fig.8. Schematic classification of deformation zone 29
Fig.9. Scheme of sheer strain deformation 34
Fig.10. Stress-strain curve of AISI 8617 39
Fig.11. Theoritical value of (a) barrel type and (b) cone type 44
Fig.12. (a) side view and (b) front view of RTP 46
Fig.13. Diameter of (a) 23°c billet and (b) 1100° billet 47
Fig.14. Criterion of measurement 48
Fig.15. Thickness change by Feed angle 52
Fig.16. (a) diameter and (b) inner_diameter change by Feed angle 53
Fig.17. Thickness change by cross angle 58
Fig.18. (a) diameter and (b) inner_diameter change by cross angle 59
Fig.19. Volume change vs Time by Cross angle (a) 10° and (b) 8° 60
Fig.20. Thickness change by Roll distance 64
Fig.21. (a) diameter and (b) inner_diameter change by Roll distance 65
Fig.22. (a) Roll distance 81mm and (b) roll distance 79.6mm 2D drawing 66
Fig.23. Volume change vs Time by Roll distance (a) 80.0mm and (b) 80.6mm 67
Fig.24. Thickness change by shoe distance at roll distance 80.0mm 71
Fig.25. (a)Diameter and (b) inner_diameter change by Shoe distance at roll distance 80.0 mm 72
Fig.26. Thickness change by Shoe distance at roll distance 80.2 mm 74
Fig.27. (a)diameter and (b) inner_diameter change by shoe distance at roll distance 80.2 mm 75
Fig.28. Volume change vs Time by Roll distance and plug diameter 78
Fig.29. Volume change vs Time by Roll distance and plug diameter 79