표제지
목차
Abstract 8
제1장 서론 10
1.1. 연구배경 10
1.2. 연구목적 및 내용 13
제2장 선박용 베어링 15
2.1. 메인 베어링(main bearing) 15
2.1.1. 베어링의 종류 16
2.2. 베어링의 필요조건 16
2.3. 베어링 메탈(bearing metal)의 재료 16
2.3.1. 주석계 화이트 메탈 17
2.3.2. 납계 화이트 메탈 19
2.3.3. Cu계 베어링 합금 20
2.3.4. 카드뮴계, 아연계 합금 20
2.3.5. 함유 베어링 20
2.4. 메인 베어링의 손상 21
제3장 베어링 접착력 검사 및 시험 24
3.1. 화이트 메탈 베어링 제작기법 24
3.2. 재료의 확산 26
3.3. 접착력 검증 방법 29
3.3.1. 결합력 확인을 위한 파괴검사 29
3.3.2. 비파괴 검사 31
제4장 검사 결과 및 고찰 38
4.1. 파괴 검사 결과 38
4.2. 미세구조 분석(microstructure analysis) 40
4.3. 초음파 탐상 검사 52
제5장 결론 58
참고문헌 59
Table 2.1. Standard for white metal(KS D 6003) 19
Table 2.2. Chemical composition of oil lite bearing 21
Table 3.1. Welding Parameter 25
Table 3.2. Basic formula for ultrasonic principle 36
Table 4.1. Bonding strength of casting and welding 38
Table 4.2. Size of test specimen and equipment 29
Fig. 1.1. Dove tail 12
Fig. 1.2. Example taken from a main bearing 12
Fig. 1.3. (a) White metal breakout during operation 13
Fig. 1.3. (b) White metal breakout during operation 14
Fig. 1.3. (c) White metal breakout during operation 14
Fig. 2.1. Split bearing 15
Fig. 2.2. HM07 18
Fig. 2.3. 11R 18
Fig. 2.4. S172 18
Fig. 2.5. WJ2 18
Fig. 2.6. Linear flaw on bearing surface 22
Fig. 2.7. Surface flaw by improper lubrication 22
Fig. 2.8. Cavitation marks 23
Fig. 2.9. Damaged by embedded foreign particle 23
Fig. 3.1. Process flow of casting 24
Fig. 3.2. Process flow of auto-welding 24
Fig. 3.3. TIG welding machine for white metal 25
Fig. 3.4. Diffusion area of Sn & Fe before heat treatment 27
Fig. 3.5. Atoms of Sn and Fe in diffusion before heat treatment 27
Fig. 3.6. Diffusion area of Sn & Fe after heat treatment 27
Fig. 3.7. Atoms of Sn and Fe in diffusion after heat treatment 27
Fig. 3.8. Concentration of Sn and Fe by diffusion 28
Fig. 3.9. Equilibrium diagram of welding diffusion 28
Fig. 3.10. Test specimen for charmel test 30
Fig. 3.11. Test equipment 30
Fig. 3.12. Penetrate testing 34
Fig. 3.13. Near field zone 37
Fig. 4.1. Test specimen (before) 39
Fig. 4.2. Test specimen (after) 39
Fig. 4.3. Test specimen (left: sampling position, right: specimen) 41
Fig. 4.4. General view of ""A-2"" microstructure, magnification 50X (left: un-etched, right: etched condition) 41
Fig. 4.5. Cross-sectional view of ""A-2"" microstructure, magnification 50X (left: un-etched, right: etched condition) 42
Fig. 4.6. General view of "A-2 " microstructure, magnification 50X (left: un-etched, right: etched condition) 43
Fig. 4.7. Cross-sectional of ""B-2"" microstructure, magnification 50X (left: un-etchcd, right: etched condition) 44
Fig. 4.8. Microstructure of "B-2" 45
Fig. 4.9. Microstructure of "A-2" 46
Fig. 4.10. Microstructure of "B-2" 47
Fig. 4.11. Microstructure of "B-2" 48
Fig. 4.12. Microstructure of A-3 49
Fig. 4.13. Microstructure of B-3 50
Fig. 4.14. SEM image and EDS analysis of "B-2" 51
Fig. 4.15. Mechanized UT testing (good bonding) 53
Fig. 4.16. Mechanized UT testing (bad bonding) 53
Fig. 4.17. Sectional views showing a large crack formed just above the bond layer 54
Fig. 4.18. Sectional views showing a large crack formed above the white Metal layer 54
Fig. 4.19. UT apparatus USM 35 55
Fig. 4.20. Probes, MB4S(Straight) and MSEB4(Dual) 55
Fig. 4.21. Reflected echo of straight beam from bottom 56
Fig. 4.22. Decreased echo by small defect 56
Fig. 4.23. Reflected echo by dual probe 57
Fig. 4.24. 2mm crack found by dual probe 57