표제지
서지정보양식
BIBLIOGRAPHIC INFORMATION SHEET
제출문
원자력신소재개발 과제 구성표
요약문
SUMMARY
표목차
그림목차
목차
제1장 서론 61
제2장 국내외 기술개발 현황 63
제3장 연구개발수행 내용 및 결과 67
제1절 중수로압력관 노외 특성시험 기술 67
1. 월성압력관의 가동중 검사 현황 67
가. '90년도 가동중 검사 68
나. '92년도 가동중 검사 68
다. '94년도 가동중 검사 69
2. 결함압력관의 DHC 평가 69
가. 서언 69
나. DHC 평가 방법론 70
(1) Sharp and crack-like 결함 70
(2) Blunt 결함 72
다. 월성압력관의 결함에 대한 DHC 평가 73
(1) M-11 압력관의 DHC 평가 73
(2) O-8 압력관의 DHC 평가 74
라. 요약 76
3. Zr-2.5Nb 압력관의 DHC 거동 78
가. 집합도에 따른 DHC 거동 78
(1) 서론 78
(2) 실험방법 79
(3) 시험결과 및 고찰 81
나. 수소화물의 크기에 따른 파괴인성 평가 84
(1) 실험방법 85
(가) 시편제작 85
(나) 수소주입 85
(다) 인장 및 파괴시험 86
(라) 수소화물 및 파면관찰 87
(2) 실험결과 87
(가) 수소화물의 형상 87
(나) 파괴인성시험 88
다. DHC 기구의 모델링 95
(1) 서론 95
(2) 실험방법 99
(가) 시편제작 99
(나) 인장시험과 DHC 시험 99
(3) 실험결과 및 고찰 99
(가) 항복강도와 KIH(이미지참조) 99
(나) DHCV model 개량 101
4. Zr-2.5Nb 압력관의 부식과 기계적 특성 103
가. 압력관 재료의 기계적 특성 103
(1) 미세조직 분석 103
(가) 실험 방법 103
(나) 미세조직 분석 결과 105
(2) 압력관 재료의 기계적 특성 106
(가) 실험 방법 106
(나) 기계적 특성 106
(3) 집합조직에 따른 강도의 변화 109
(4) 결론 116
나. Zr-Nb합금의 부식 및 수소흡수 117
(1) Zr-2.5Nb 합금의 부식에 대한 환경효과 117
(가) 시편 및 실험장치 118
(나) 결과 및 분석 119
(다) 요약 123
(2) Zr-Nb 합금의 Oxide 형성에 관한 연구 123
(가) Zr-Nb 합금의 고온·고압수에서의 Oxide 형성 125
(나) Zr-2.5Nb 합금의 산화막 X-선 미세분석 132
(3) CANDU 압력관의 수소흡수 특성 연구 137
(가) 월성 1호기 압력관의 수소흡수 거동 분석 139
(나) Zr-2.5Nb 합금의 수소흡수 및 부식특성 변화 145
(4) Zr-2.5Nb 압력관의 Hydride Blistering 연구 150
(가) Zr-2.5Nb 압력관의 구조 및 건전성 151
(나) CANDU 압력관의 사고 발생현황 153
(다) Hydride Blister에 대한 Acceptance Criteria 154
(라) Hydride Blister에 대한 연구 159
5. 러시아 및 CANDU 압력관의 특성 평가 164
가. 시편제작 165
나. 미세조직 165
다. 집합도 169
라. 인장강도 171
마. 크립 특성 171
바. DHC특성 173
사. 파괴 인성 174
아. 부식특성 175
제2절 압력관용 Zr-Nb합금 개발 176
1. 합금설계방향 176
가. 압력관 파손사례 및 파손기구 176
(1) 파손사례 176
(2) 압력관 파손기구 177
(3) Zr 합금관련 선진국의 연구현황 182
나. DHC 저항성 신합금 설계 183
(1) 합금설계 방안 184
(2) 내식성 및 DHC관점에서 첨가원소의 영향 186
(3) DHC저항성 예비합금 설계 189
다. 크립 저항성 신합금 설계 190
2. 저부식/내DHC 저항성 지르코늄합금 193
가. 일차후보합금 193
나. 2차후보합금 195
(1) 제조공정의 최적화 연구 195
(2) 1st batch 합금의 특성평가 197
(3) 2nd batch 합금 설계 및 특성평가 200
다. 저부식성/내DHC성 지르코늄합금 선정 204
라. 지르코늄합금 제조공정기술의 기반연구 결과 205
(1) 지르코늄합금의 진공아크용해 및 합금조성 제어연구 205
(2) 열처리 조건에 따른 지르코늄합금의 부식저항성 208
(3) Fe첨가에 따른 지르코늄합금의 재결정 가속화 현상 213
(4) 실험방법 214
3. 고크립강도 합금개발 217
가. 합금 설계 217
나. 실험방법 218
(1) 제조공정 218
(2) 분석 방법 225
다. 실험결과 및 토의 231
(1) Zr-1Nb-0.5Sn-xMo합금 231
(2) Zr-1.0Nb-0.5Sn-0.5Cr-xMo, Zr-1.0Nb-0.5Cr-0.5Mo, Zr-1.0Nb-xMo 및 Zr-0.5Nb-1.0Sn-xMo합금 246
(3) Zr-1.0Nb-1.0Sn 및 Zr-1.0Nb-1.0Sn-0.5Mo실험합금 262
(4) 다중 회귀분석 270
(5) Zr-Nb합금계의 인장특성에 미치는 열간 압연온도 및 시효경화의 영향 271
(가) 실험합금 선정 272
(나) 실험합금 제조공정 272
(다) 잉고트(Ingot) 제조조건 및 성분 분석 결과 273
(라) 용해, 단조, 균질화 열처리의 미세조직 274
(마) 열간 압연온도에 따른 상변태 거동 275
(바) 열간 압연온도에 따른 미세조직 변화 277
(사) 열간 압연온도에 따른 인장특성 변화 280
(아)/(자) 열간 압연재의 시효경화시 인장특성 변화 282
(자)/(차) 열간 압연재의 시효경화시 미세조직 변화 283
(차)/(카) 냉간 압연량 결정 및 냉간 압연재의 인장특성 284
(카)/(타) 최종 열처리재의 인장특성 285
(6) Zr-1Nb-0.5Mo실험합금 288
4. 요약 291
제3절 지르코늄합금의 개량 연구 292
1. Sol-Gel Coating에 의한 Zr합금의 내식성 향상 연구 292
가. 서론 292
나. 졸-겔법을 이용한 세라믹스 박막제 292
(1) 금속알콕사이드(Metal alkoxides)와 겔화과정 293
(2) 박막제조방법 294
(3) 졸-겔 코팅에 의한 스텐레스강의 내부식성 및 내산화성 향상 298
(4) 세라믹스 박막의 특성평가 300
(가) 박막의 구조 301
(나) 기계적·열적 성질 분석 303
(다) 화학조성 분석 306
다. 실험방법 307
(1) Colloidal sol을 이용한 코팅실험 307
(2) Alkoxide sol을 이용한 코팅실험 308
라. 실험결과 308
2. 지르코니아의 상전이 연구 309
가. 연구의 목적 309
나. 실험방법 310
(1) 원료분말 및 용액제조 310
(2) 시편특성조사 및 열처리 시험 310
다. 결과 및 고찰 311
라. 요약 312
제4절 결론 313
제4장 연구개발 목표 달성도 및 대외기여도 318
제5장 연구개발결과의 활용계획 321
제6장 참고문헌 323
[부록: Acoustic emission에 의한 DHC 측정기술][원문불량;p.502~505,524,528,537,553,572,600~602,631~633,655~660] 334
판권지 734
[title page etc.]
[BIBLIOGRAPHIC INFORMATION SHEET etc.]
Contents
Chapter 1. Introduction 61
Chapter 2. State of Art 63
Chapter 3. Research Results 67
3-1. Characterization of Pressure Tubes 67
3-1-1. In-Service Inspection of Wolsung Unit-1 67
3-1-1-1. ISI Results in 1990 68
3-1-1-2/3-1-1-1. ISI Results in 1992 68
3-1-1-3/3-1-1-1. ISI Results in 1994 69
3-1-2. Evaluation of DHC on Pressure Tubes with surface flaws 69
3-1-2-1. Introduction 69
3-1-2-2. DHC Evaluation Methodology 70
3-1-2-2-1. Sharp and Crack-like Flaws 70
3-1-2-2-2. Blunt Flaws 72
3-1-2-3. Evaluation of DHCV Susceptibility of Wolsung 1 73
3-1-2-3-1. Pressure Tube M-11 73
3-1-2-3-2. Pressure Tube O-8 74
3-1-2-4. Summary 76
3-1-3. DHC Behavior of Zr-2.5Nb Pressure Tube 78
3-1-3-1. Texture Effect on DHC 78
3-1-3-1-1. Introduction 78
3-1-3-1-2. Experimental 79
3-1-3-1-3. Results and Discussion 81
3-1-3-2. Hydride Effects on Fracture Toughness 84
3-1-3-2-1. Experimental 85
3-1-3-2-2. Results and Discussion 87
3-1-3-3. DHC Modeling 95
3-1-3-3-1. Introduction 95
3-1-3-3-2. Experimental 99
3-1-3-3-3/3-1-3-3-2. Results and Discussion 99
3-1-4. Corrosion and Mechanical Behavior of 103
3-1-4-1. Characterization of Zr-2.5Nb Pressure Tubes 103
3-1-4-1-1/3-1-4-1. Microstructure 103
3-1-4-1-2/3-1-4-2. Mechanical Properties 106
3-1-4-1-3/3-1-4-3. Texture Effect on Strength 109
3-1-4-1-4/3-1-4-4. Conclusion 116
3-1-4-2. Corrosion and Hydrogen Pick-up of Zr-2.5Nb alloy 117
3-1-4-2-1. Environmental Effect on Corrosion of Zr-2.5Nb 117
3-1-4-2-2. Study of the oxide on Zr-Nb alloys 123
3-1-4-2-3. Hydrogen Pickup Behavior of 137
3-1-4-2-4. Hydride Blistering of Zr-2.5Nb Pressure Tubes 150
3-1-5. Characterization of CANDU and Russian Tubes 164
3-1-5-1. Testing Specimens 165
3-1-5-2. Microstructural Characteristics 165
3-1-5-3. Textures 169
3-1-5-4. Tensile Strength 171
3-1-5-5. Creep Properties 171
3-1-5-6. Delayed Hydride Cracking 173
3-1-5-7. Fracture Toughness 174
3-1-5-8. Corrosion 175
3-2. Development of Improved Zirconium Alloys for Pressure Tubes 176
3-2-1. Alloy Design Basis 176
3-2-1-1. Incidents of Pressure(Pressur) Tube Failures and Failure Mechanism 176
3-2-1-1-1. Incidents of Pressure Tube Failures 176
3-2-1-1-2. Failure Mechanism 177
3-2-1-1-3. Review of Development of Improved Zirconium Alloys 182
3-2-1-2. Design of DHC Resistant Zirconium Alloys 183
3-2-1-2-1. Design Basis 184
3-2-1-2-2. Effect of Alloying Elements on Corrosion and Strength 186
3-2-1-2-3. Preliminary Design of Creep Resistant Zirconium Alloys 189
3-2-2. Zirconium Alloys with Better Corrosion-and DHC 193
3-2-2-1. First Candidate Alloys 193
3-2-2-2. Second Candidate Alloys 195
3-2-2-2-1/3-2-2-1. Optimization of Manufacturing Procedures 195
3-2-2-2-2/3-2-2-2. Evaluation of 1st Batch Alloys 197
3-2-2-2-3/3-2-2-3. Design and Evaluation of 2nd Batch Alloys 200
3-2-2-3. Selection of Zirconium Alloys with Best Corrosion- and DHC-Resistance 204
3-2-2-4. Basic Research related to Manufacturing Technologies of Zirconium Alloys 205
3-2-2-4-1. Determination of Added Values for Main Alloying Elements during VAR. 205
3-2-2-4-2. Effect of Heat Treatment on Corrosion of Zirconium Alloys 208
3-2-2-4-3. Accelerated Recrystallization by Fe in Zirconium Alloys 213
3-2-3. Design of Zirconium Alloys with Higher Creep Strength 217
3-2-3-1. Alloy Design 217
3-2-3-2. Experimental 218
3-2-3-2-1. Manufacturing Procedure 218
3-2-3-2-2. Analytical Methods used 225
3-2-3-3. Results and Discussion 231
3-2-3-3-1. Zr-1Nb-0.5Sn-xMo 231
3-2-3-3-2. Zr-1.0Nb-0.5Sn-0.5Cr-xMo, Zr-1.0Nb-0.5Cr-0.5Mo, Zr-1.0Nb-xMo and Zr-0.5Nb-1.0Sn-xMo 246
3-2-3-3-3. Zr-1.0Nb-1.0Sn and Zr-1.0Nb-1.0Sn-0.5Mo 262
3-2-3-3-4. Multi-Regression Analysis 270
3-2-3-3-5. Effect of Hot Rolling Temperature and Aging on Tensile Properties of Zr-Nb alloys 271
3-2-3-3-6. Zr-1Nb-0.5Mo 288
3-2-4. Summary of Design of Improved Zirconium Alloys 291
3-3. Studies on the Improvement of Pressure Tubes 292
3-3-1. Sol-Gel Coating of Zirconia on the Surface of Pressure Tubes 292
3-3-1-1. Introduction 292
3-3-1-2. Ceramic Film by Sol-Gel Method 292
3-3-1-2-1. Gel Process and Alkoxide 293
3-3-1-2-2. Manufacturing of Ceramic Thin Film 294
3-3-1-2-3. Improved Corrosion- and Oxidation-Resistance of Stainless Steel by Sol-Gel Coating 298
3-3-1-2-4. Characterization of Coated Thin Layer 300
3-3-1-3. Experimental 307
3-3-1-4. Results 308
3-3-2. Study on the Phase Transition of Tetragonal Zirconia 309
3-3-2-1. Objective 309
3-3-2-2. Experimental 310
3-3-2-2-1. Preparation of Zr(OH)4 powder 310
3-3-2-2-2. Characterization of the Specimens and Thermal Treatment 310
3-3-2-3. Results and Discussion 311
3-3-2-4. Summary 312
3-4. Conclusion 313
Chapter 4. Assessment of Fulfillment of Objectives and Social Contribution 318
Chapter 5. Proposals for Utilization of Results 321
Chapter 6. References 323
Appendix 1. Application of Acoustic(Aoustic) Emission Technique to DHC[원문불량;p.502~505,524,528,537,553,572,600~602,631~633,655~660] 334
copyright 734
Table 1.1.1. Calculation of flaw growth at M-11 pressure tube during cooldown cycle 345
Table 1.1.2. Calculation of flaw growth at O-8 pressure tube during cooldown cycle. 346
Table 1.1.3. Yield strength and threshhold stress intensity factor 347
Table 1.1.4. Comparison of measured and calculated basal pole components 347
Table 1.1.5. Tensile data summary of Trans. (0° tilted specimen) in as-received and recrystallized pressure tube 348
Table 1.1.6. Tensile data summary of Long. (90° tilted specimen) in as-received and recrystallized pressure tube 349
Table 1.1.7. Tensile data summary of 45° tilted specimen in as-received and recrystallized pressure tube. 350
Table 1.1.8. Tensile data summary of 30° tilted specimen in as-received and recrystallized pressure tube. 351
Table 1.1.9. Summary of heat treatments given to Zr-Nb alloys 352
Table 1.1.10. X-ray Reflections of Zr Matrix and Oxide. 353
Table 1.1.11. Analysis of the diffraction peaks of quenched and aged Zr-20%Nb alloys corroded in 400℃ steam for 58 days 354
Table 1.1.12. Analysis of the diffraction peaks of annealed Zr-1%Nb alloys corroded in 400℃ steam for 58 days 355
Table 1.1.13. X-ray Reflection intensities of Zr-2.5Nb and Zircaloy-4. 356
Table 1.1.14. X-ray Reflections of Zr Matrix and Oxide by using Cu K-a Radiation (in d-spacing). 357
Table 1.1.15. X-ray Reflection Angles (in 2θ) of Zr Matrix and Oxide by using Cu K-a Radiation 358
Table 1.1.16. Design Data of CANDU Nuclear Reactors 359
Table 1.1.17. Hydrogen Contents of Zr-2.5Nb Alloys after Hydrogen Charging. 360
Table 1.1.18. Specification of Chemical Compositions (alloying elements in wt.%, impurities in wt.ppm) of Zr-2.5Nb, Zircaloy-2, and Type 403 Stainless Steel. 360
Table 1.1.19. Summary of the Design Parameters of Fuel Channel Assemblies for a modern CANDU reactor (Wolsong Unit 2). 361
Table 1.1.20. Summary of CANDU Pressure Tube Failure Accidents. 362
Table 1.1.21. Initially Proposed Test Program (TDVI-388). 363
Table 1.1.22. Chemical Composition of Ingot: a) CANDU pressure Tube. 364
Table 1.1.23. Structure Characteristics of Tubes Studied. 366
Table 1.1.24. Parameters of Texture for Tubes Investigated. 367
Table 1.1.25. Results of Pressure Tube Tensile Tests upon Uniaxial Tension 368
Table 1.1.26. Test Result of axial creep at 300℃ and 325℃ 369
Table 1.1.27. DHC velocity of Russian pressure tubes at 200℃, with 20 MPam1/2.(이미지참조) 370
Table 2.1.1. Failure Experience of Pressure Tube 371
Table 2.1.2. Development of Various Zr-based Alloys 372
Table 2.1.3. Physical Properties of Metal Elements 373
Table 2.1.4. Preliminary Alloy Design and Chemical Composition of New Zr-based Alloys 374
Table 2.1.5. Design of 30 kinds of high strength zirconium alloys 375
Table 2.2.1. Comparison of properties of KAERI made Zircaloy-4 and Zr-2.5Nb, and ASTM specification requirements: (a) weight gain in steam at 400℃ for 3 days and (b) mechanical properties 376
Table 2.2.2. Chemical analysis of the 1st batch alloys (analyzed by KAERI) 377
Table 2.2.3. Mechanical and corrosion characteristics of the 1st batch alloys 378
Table 2.2.4. Mechanical and corrosion characteristics of the 2nd batch alloys 379
Table 2.2.5. Design of the 3rd batch alloys and their analyzed composition 380
Table 2.2.6. Mechanical and corrosion characteristics of the 3rd batch alloys 381
Table 2.2.7. Characteristics of 7 candidate alloys with high corrosion resistance and strength 382
Table 2.2.8. Chemical analysis of the 1st batch of the 7 candidate alloys 383
Table 2.2.9. Mechanical and corrosion characteristics of the 7 candidate alloys 384
Table 2.2.10. Weight Gain of 7 Candidate Alloys (1st. Batch) after corrosion in 350℃ 385
Table 2.2.11. Weight Gain of 7 Candidate Alloys (1st. Batch) when corroded in 400℃, steam 386
Table 2.2.12. Design of the 2nd batch of the 7 candidate alloys and their chemical analysis 387
Table 2.2.13. Mechanical and corrosion properties of the 2nd batch of 7 candidate alloys 388
Table 2.2.14. Hydrogen pickup fraction and its content of the 2nd batch alloys after corrosion in 350℃, water for 255 days 389
Table 2.2.15. Hydrogen pick-up fraction of 2nd batch alloys after corrosion in 400℃ for 255 days 390
Table 2.2.16. Texture and Phase Analyses of the 2nd Batch Alloys 391
Table 2.2.17. Evolution of creep strains with time of Zr1Nb2Sn0.3V, Zr1Nb2Sn0.3Fe and Zr-2.5Nb 392
Table 2.2.18. Determination of the weighting factors of main alloying elements during vacuum arc remelting 393
Table 2.2.19. Cumulative Annealing Parameters, ∑A of Zr1Nb0.8Sn0.3Fe and Zr1Nb0.8Sn0.3Te alloys 395
Table 2.2.20. Chemical composition of the alloys 396
Table 2.3.1. Ingot geometry after melting 397
Table 2.3.2. Adjustment of alloying elements to meet targets 398
Table 2.3.3. Chemical analysis of Zr-1Nb-0.5Sn-xMo experimental alloys. 399
Table 2.3.4. Comparison of interstitial contents of Zr-1Nb-0.5Sn-xMo experimental alloys melted by Plasma Arc Remelting and Electron Beam Remelting 400
Table 2.3.5. Chemical analysis of experimental alloys 401
Table 2.3.6. Tensile properties of the experimental alloys heat treated at 400℃ for 24h 402
Table 2.3.7. Tensile properties of the experimental alloys heat treated at 650℃ for 3h 403
Table 2.3.8. Chemical analysis of the experimental alloys 404
Table 2.3.9. Results of partial multiple regression of alloys design 405
Table 2.3.10. Results of partial multiple regression of heat treatment 406
Table 2.3.11. Selected experimental alloys 407
Table 2.3.12. Conditions of plasma arc remelting 408
Table 2.3.13. Chemical analysis of the experimental alloys 409
Table 2.3.14. Conditions of the differential thermal analysis 410
Table 2.3.15. Heat treatment conditions for the experimental alloys 411
Table 2.3.16. Chemical analysis for Zr-1Nb-0.5Mo experimental alloys 412
Table 2.3.17. Kearns number and β-phase fraction of the experimental alloys 413
Table 2.3.18. Tensile properties of Zr-1Nb-0.5Mo alloys at room temperature and 300℃ 414
Fig.1.1.1. Schematic diagram of DHC device. 415
Fig.1.1.2. Delayed Hydride Cracking Velocity of Zr-2.5Nb Pressure Tube. 416
Fig.1.1.3. Compact tension specimen tested at 200℃(200 ppm[H]): (a) longitudinal specimen, (b) circumferential specimen. 417
Fig.1.1.4. Metallographic profiles showing reoriented hydrides near the crack: (a) longitudinal specimen, (b) circumferential specimen. 417
Fig.1.1.5. Hydrides at the crack tip of circumferential specimen. 417
Fig.1.1.6. Hydride reorientation at CT specimen.(loading direction :longitudinal) 418
Fig.1.1.7. Schematic representation of compact tension specimen. 418
Fig.1.1.8. Hydride morphology of the furnace-cooled specimen in the radial-circumferential plane of the tubes with (a) 50 ppm, (b) 120 ppm and (c) 200 ppm. 419
Fig.1.1.9. Hydride morphology of the air-cooled specimen in the radial-circumferential plane of the tubes with (a) 50 ppm, (b) 120 ppm and (c) 200 ppm. 420
Fig.1.1.10. Hydride morphology of the water-cooled specimen in the radial-circumferential plane of the tubes with (a) 120 ppm and (b) 200 ppm. 421
Fig.1.1.11. Typical load and electrical potential vs. load point displacement in fracture toughness tests. Crack initiation indicated "X":(a)-(e) (a) Air-cooled with 200ppm hydrogen tested at room temperature. 422
Fig.1.1.12. Maximum load toughness vs. hydrogen concentration at room temperature. 427
Fig.1.1.13. Metallographic fracture surface profile of the air-cooled specimen with 200 ppm tested at room temperature 428
Fig.1.1.14. J-R curves for furnace-cooled specimens tested at room temperature. 428
Fig.1.1.15. Metallographic Fracture Surface Profile of the Furnace-cooled Specimen with 200 ppm tested at Room Temperature. 429
Fig.1.1.16. Fracture Surface of the Furnace-cooled with 200 ppm Hydrogen tested at Room Temperature 430
Fig.1.1.17. J-R Curves for Water-quenched Specimens tested at Room Temperature. 431
Fig.1.1.18. SEM showing the Fracture Surface of the Air-cooled Specimen with 50 ppm Hydrogen tested at Room Temperature. 432
Fig.1.1.19. Maximum Load Fracture Toughness vs. Hydrogen Concentration at 150℃. 433
Fig.1.1.20. Maximum Load Fracture Toughness vs. Hydrogen Concentration tested at 240℃. 434
Fig.1.1.21. Geometry of crack and hydrides used in model calculations. 435
Fig.1.1.22. Theoretical and experimental plots of crack velocity/stress intensity factor for Zr-2.5Nb alloy at 250℃. 436
Fig.1.1.23. Spatial geometry of various textured tensile specimen in Zr-2.55 Nb pressure tube. 437
Fig.1.1.24. TEM microstructure of Zr-2.5% Nb standard pressure tube in a) radial normal plane, b) transverse normal plane. 438
Fig.1.1.25. TEM microstructure and X-ray spectra in Zr-2.5% Nb standard pressure tube in radial normal plane. 439
Fig.1.1.26. Inverse pole figure for as-received pressure tube 440
Fig.1.1.27. Inverse pole figure for tilted specimen. 440
Fig.1.1.28. Strain-stress curves of as-received PT specimen having various basal pole component at room temp 441
Fig.1.1.29. Strain-stress curves of as-received PT specimen having various basal pole component at 330℃. 442
Fig.1.1.30. Strain-stress curves of recrystallized (750℃-2hr), specimen having various basal pole component at room temperature. 443
Fig.1.1.31. Temperature dependency of yield and tensile strength of as-received and annealed (750℃-hr) PT in transverse direction (F=0.67). 444
Fig.1.1.32. Temperature dependency of yield and tensile strength of as-received and annealed (750℃-hr) PT in longitudinal direction(F=0.06). 445
Fig.1.1.33. Temperature dependency of yield and tensile strength of as-received and annealed (750℃-hr) PT in 45° tilted direction from transverse (F=0.30). 446
Fig.1.1.34. Temperature dependency of yield and tensile strength of as-received and annealed (750℃-hr) PT in 30° tilted direction from transverse (F=0.42). 447
Fig.1.1.35. Spatial texture distribution in pressure tube. 448
Fig.1.1.36. Comparison of temperature dependency of yield strength in specimen having basal pole component (F) in as-received pressure tube. 449
Fig.1.1.37. Comparison of temperature dependency of yield strength in specimen having various basal pole component (F) in recrystallized (750℃-2hr) pressure tube. 450
Fig.1.1.38. Comparison of basal pole component (F) dependency of tensile strength in as-received and recrystallized specimen at room temperature. 451
Fig.1.1.39. Comparison of temperature dependency of tensile strength in specimen having various basal pole component (F) in as-received pressure tube. 452
Fig.1.1.40. Comparison of basal pole component (F) dependency of yield strength in as-received and recrystallized specimen at room temperature. 453
Fig.1.1.41. Comparison of texture dependency of work hardening capability with temperature in as-received P/T 454
Fig.1.1.42. Change in weight gain with oxidation time obtained from the Zr-2.5Nb alloy in H₂O and D₂O steam of 10MPa at 400℃ 455
Fig.1.1.43. Change in weight gain with oxidation time obtained from the Zr-2.5Nb alloy in H₂O steam of 10MPa and O₂ gas at 400℃. 456
Fig.1.1.44. X-ray diffraction patterns of oxide grown on Zr-2.5Nb specimen in H₂O steam at 400℃ for 1,10, 58 days. (a) Quenched and Aged specimen (α-Zr+β-Nb) and (b) Annealed specimen (α-Zr+β-Zr) 457
Fig.1.1.45. X-ray diffraction patterns of oxide grown on Zirclaoy-4 specimen in H₂O steam at 400℃ for 1, 10, 58 days. 458
Fig.1.1.46. X-ray diffraction patterns of oxide grown on Quenched Zr-1%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 459
Fig.1.1.47. X-ray diffraction patterns of oxide grown on Quenched Zr-2.5%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 460
Fig.1.1.48. X-ray diffraction patterns of oxide grown on Quenched Zr-5%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 461
Fig.1.1.49. X-ray diffraction patterns of oxide grown on Quenched Zr-10%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 462
Fig.1.1.50. X-ray diffraction patterns of oxide grown on Quenched Zr-15%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 463
Fig.1.1.51. X-ray diffraction patterns of oxide grown on Quenched Zr-20%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 464
Fig.1.1.52. X-ray diffraction patterns of oxide grown on Quenched and Aged Zr-1%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 465
Fig.1.1.53. X-ray diffraction patterns of oxide grown on Quenched and Aged Zr-2.5%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days 466
Fig.1.1.54. X-ray diffraction patterns of oxide grown on Quenched and Aged Zr-5%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 467
Fig.1.1.55. X-ray diffraction patterns of oxide grown on Quenched and Aged Zr-10%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 468
Fig.1.1.56. X-ray diffraction patterns of oxide grown on Quenched and Aged Zr-15%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 469
Fig.1.1.57. X-ray diffraction patterns of oxide grown on Quenched and Aged Zr-20%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 470
Fig.1.1.58. X-ray diffraction patterns of oxide grown on Annealed Zr-1%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 471
Fig.1.1.59. X-ray diffraction patterns of oxide grown on Annealed Zr-2.5%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 472
Fig.1.1.60. X-ray diffraction patterns of oxide grown on Annealed Zr-5%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 473
Fig.1.1.61. X-ray diffraction patterns of oxide grown on Annealed Zr-10%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 474
Fig.1.1.62. X-ray diffraction patterns of oxide grown on Annealed Zr-15%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 475
Fig.1.1.63. X-ray diffraction patterns of oxide grown on Annealed Zr-20%Nb specimen in H₂O steam at 400℃ for 1, 10, 58 days. 476
Fig.1.1.64. The X-ray patterns of a Zr-2.5Nb specimen (Quenched) after oxidation at 400℃ (oxide thickness 1.9 ㎛): (a) Intensity 9,000, (b) Intensity 3,000. 477
Fig.1.1.65. The X-ray patterns of a Zr-2.5Nb specimen (Quenched) after oxidation at 400℃ (oxide thickness 400 ㎛) (a) Intensity 2000, (b) Intensity 700. 478
Fig.1.1.66. The X-ray patterns of a Zr-2.5Nb specimen (Quenched and Aged) after oxidation at 400℃ (oxide thickness 1.0 ㎛): (a) Intensity 5000, (b) Intensity 1,000. 479
Fig.1.1.67. The X-ray patterns of a Zr-2.5Nb specimen (Quenched and Aged) after oxidation at 400℃ (oxide thickness 10.0 ㎛): (a) Intensity 11,000, (b) Intensity 1000. 480
Fig.1.1.68. The X-ray patterns of a Zircaloy-4 specimen after oxidation at 400℃ (oxide thickness 1.1 ㎛) (a) Intensity 1500, (b) Intensity 700. 481
Fig.1.1.69. Deuterium Concentration in Zirconium Alloy Pressure Tubes. 482
Fig.1.1.70. Long-term hydrogen pick-up of cold-worked Zr-2.5Nb and Zircaloy-2 pressure tubes. 483
Fig.1.1.71. Long-term oxidation of cold-worked Zr-2.5Nb and Zircaloy-2 pressure tubes. 484
Fig.1.1.72. Deuterium concentration along Zr-2.5Nb pressure tubes from Bruse(1300-2790 EFPD) and Wolsong-1 (2947 EFPD) NGSs. 485
Fig.1.1.73. Deuterium concentration along Zr Alloy pressure tubes from Pickering, Bruce (1300-2790 EFPD) and Wolsong-1 (2947 EFPD) NGSs. 486
Fig.1.1.74. Wolsong-1 Deuterium Uptake Model. 487
Fig.1.1.75. Solubility of hydrogen in zirconium alloys 488
Fig.1.1.76. Change in weight gain with oxidation time obtained from the Zr-2.5Nb alloy in H₂O steam of 10 MPa at 400℃. 489
Fig.1.1.77. Schematic of a fuel channel for a CANDU reactor with pressurized water coolant. 490
Fig.1.1.78. Fracture of the G 16 pressure tube of Pickering reactor 490
Fig.1.1.79. Equivalent depth of hydride. 490
Fig.1.1.80. Methodology for deterministic analysis of pressure tube hydride blisters. 491
Fig.1.1.81. Cross sectional view of the test facility tank. 492
Fig.1.1.82. Schematic showing the arrangement of the curved pressure tube section between the shaped Al block and Zr-Nb plate 492
Fig.1.1.83. Schematic Diagram of Hydride Blistering Test Apparatus. 493
Fig.1.1.84. Schematic diagram of the four-point bending jig including the specimen heaters used on the high-temperature tests. 493
Fig.1.1.85. The schematic description of the tube pieces cutting into sections 494
Fig.1.1.86. The type of the segment which was cut off from each semi-annulus 494
Fig.1.1.87. CANDU pressure tube structure as seen in optical microscope: a) axial section, b) transverse section, c) in the wall plane. 495
Fig.1.1.88. CANDU pressure tube microstructure in the axial(a-SEM, c-TEM) and transverse sections(b-SEM, d-TEM). 496
Fig.1.1.89. Electron diffraction of the CANDU pressure tube with the β-Nb and β-Zr phase reflection (a, b);β-phase lattice parameter vs. Nb content (c);β-Zr phase particle spectrum (d);β-Nb phase particle spectrum (e). 497
Fig.1.1.90. Interlayers of β-Zr phase with β-Nb phase particles in the CANDU pressure tube structure:a) and c) light field images ; b) and d) dark field images in β-Nb phase reflections. 499
Fig.1.1.91. E-125 pressure tube structure as seen in optical microscope : a) axial section; b) transverse section; c) in the wall plane; x800. 500
Fig.1.1.92. E-125 pressure tube microstructure: a) axial section,... 501
Fig.1.1.93. β-Nb phase precipitates in the E-125 pressure tube structure: a) and c) light field images, b) dark field images in β-Nb phase reflections, d) polygonized structure(stucture). 503
Fig.1.1.94. E-635 pressure tube structure as seen in optical microscope : a) axial section; b) transverse section; c) in the wall plane; x400. 504
Fig.1.1.95. E-635 pressure tube microstructure: a) axial section, TEM; b) transverse section, TEM; c) spectrum of α-Zr phase; d) spectrum of precipitate particles. 505
Fig.1.1.96. Sketch of preparation of samples for the x-ray analysis of tube structure and texture. 507
Fig.1.1.97. Direct pole figure of CANDU pressure tube sample 1 (a) (0001), (b) (1120)[원문불량;p.502] 508
Fig.1.1.98. Direct pole figure of CANDU pressure tube sample 6 (a) (0001), (b) (1120).[원문불량;p.503] 509
Fig.1.1.99. Direct pole figure of E-125 pressure tube sample 1 (a) (0001), (b) (1120).[원문불량;p.504] 510
Fig.1.1.100. Direct pole figure of E-125 pressure tube sample 6 (a) (0001), (b) (1120).[원문불량;p.505] 511
Fig.1.1.101. Direct pole figure of E-635 pressure tube sample (a) (0001), (b) (1120). 512
Fig.1.1.102. Pole density of (0001) vs. tilt angle at CANDU pressure tube: a) sample 1, b) sample 6. 513
Fig.1.1.103. Pole density of (0001) vs. tilt angle at E-125 pressure tube: a) sample 1, b) sample 6. 514
Fig.1.1.104. Diffraction reflections (100) of x-ray spectrum record for L-samples of the tubes studied: a) E-125, b) CANDU. 515
Fig.1.1.105. Pressure tube sample for axial creep test 516
Fig.1.1.106. Creep of E125 and E635 tubes under uniaxial stress at 400℃ 517
Fig.1.1.107. Creep of E125 and E635 tubes under 150 MPa at 400℃ 518
Fig.1.1.108. J-R curves of the Russian pressure tubes with 100ppm hydrogen: a) at R. T., b) at 300℃ 519
Fig.1.1.109. Corrosion behavior of Russian tubes and Zr-2.5Nb with different heat treatment in 350℃, water. 520
Fig.1.1.110. Corrosion behavior of Russian tubes in 400℃, steam. 521
Fig.2.2.1. Manufacturing process of the 1st batch alloys 522
Fig.2.2.2. Modified manufacturing process of the 2nd batch alloys 523
Fig.2.2.3. Parametric study to optimize the manufacturing process 524
Fig.2.2.4. Optimized manufacturing procedures of the 7 candidate alloys 525
Fig.2.2.5. Change of temperature in a cladded zirconium ingot during a hot rolling step 526
Fig.2.2.6. Microstructures of Zr0.8Nb1.7Sn0.8Fe and Zr0.4Nb1.3Sn0.3Te after final annealing at different temperatures 527
Fig.2.2.7. Microstructures of Zr0.4Nb1.7Sn0.6Fe and Zr1.1Nb1.6Sn0.4Te after final annealing at different temperatures 528
Fig.2.2.8. Microstructures of Zr1.1Nb4.0Sn0.7Fe and Zr1.1Nb4.0Sn0.4V after final annealing at different temperatures 529
Fig.2.2.9. Microstructures of Zr0.9Nb0.6Fe and Zr2.7Nb after final annealing at different temperatures[원문불량;p.524] 530
Fig.2.2.10. Weight gain with time of the 1st batch of the 7 candidates with stress relieving treatment at 400 ℃ for 24 h when corroded in 400 ℃, steam 531
Fig.2.2.11. Weight gain with time of the 1st batch of the 7 candidates with final treatment at 500 ℃ for 3h when corroded in 400 ℃, steam 532
Fig.2.2.12. Weight gain with time of the 1st batch of the 7 candidates with final treatment at 600 ℃ for 3h when corroded in 400 ℃, steam 533
Fig.2.2.13. Change of the corrosion resistance of zirconium alloys containing Te and Fe with final annealing temperatures when corroded in 400 ℃, steam[원문불량;p.528] 534
Fig.2.2.14. Microstructures of the 2nd batch of the 7 candidates after intermediate annealing before the last cold rolling: (a) Zr1Nb0.5Sn0.1Te,... 535
Fig.2.2.15. Microstructures of the 2nd batch of the 7 candidates after final cold rolling: (a) Zr1Nb0.5Sn0.1Te,... 537
Fig.2.2.16. Microstructures of the 2nd batch of the 7 candidates after final annealing at 400 ℃ for 24 h: (a) Zr1Nb0.5Sn0.1Te,... 539
Fig.2.2.17. Corrosion behavior of the 2nd batch of the 7 candidates with different final annealing after corrosion in 400 ℃, steam: (a) at 400 ℃ for 24h and (b) at 500 ℃ for 3h 541
Fig.2.2.18. Corrosion behavior of the 2nd batch of the 7 candidates with different final annealing after corrosion in 350 ℃, water:(a) at 400 ℃ for 24h and (b) at 500 ℃ for 3h 542
Fig.2.2.19. Tensile strength at 300 ℃ of 2nd batch alloys of the 7 candidates along with that of Zr2.3Nb standard alloy[원문불량;p.537] 543
Fig.2.2.20. Hydrogen pickup fraction of the 2nd batch alloys after corrosion in 350 ℃, water. 544
Fig.2.2.21. Hydrogen pickup fraction of the 2nd batch alloys after corrosion in 400 ℃, steam 545
Fig.2.2.22. Creep resistance of Zr1Nb1.3Sn0.3V, Zr1Nb1.2Sn0.2Fe and Zr2.5Nb (standard alloys) at 400 ℃ in the uniaxal loading of 150 MPa 546
Fig.2.2.23. Change of the zirconium ingot structures with Fe contents (a)Pure Zr (b)0.4wt.% Fe (c)1.3wt.% Fe (d) 3.0wt.% Fe 547
Fig.2.2.24. Additional heat treatment for Zr1Nb0.4Sn0.1Te and Zr1Nb0.4Sn0.1Fe sheets 548
Fig.2.2.25. The effect of final annealing temperature on the corrosion of Zr1Nb0.4Sn0.1Te after corrosion in 400 ℃ steam for 90 days. 549
Fig.2.2.26. The effect of final annealing temperature on the corrosion of Zr1Nb0.4Sn0.1Fe after corrosion in 400 ℃ steam for 90 days. 550
Fig.2.2.27. The effect of final annealing temperature on the corrosion of Zr1Nb0.4Sn0.1Te after corrosion in the LiOH solution with (a) 3.5 ppm or (b) 350 ppm Li for 90 days at 350 ℃. 551
Fig.2.2.28. The effect of final annealing temperature on the corrosion of Zr1Nb0.4Sn0.1Fe after corrosion in the LiOH solution with (a) 3.5 ppm or (b) 350 ppm Li for 90 days at 350 ℃. 552
Fig 2.2.29. The hydrogen pickup fraction with final annealing temperatures of Zr1Nb0.4Sn0.1Te and Zr1Nb0.4Sn0.1Fe. 553
Fig.2.2.30. Temperature difference measured by a DSC during heating up of Zr1Nb0.3Sn0.1Te and Zr1Nb0.4Sn0.1Fe. 554
Fig.2.2.31. Microstructures of cold-rolled Zr1Nb0.3Sn0.1Te after various final annealing temperatures: (a) 500 ℃ x 2h, (b) 550 ℃ x 2h, (c) 600 ℃ x 2h, (d) 650 ℃ x 2h and (e) 680 ℃ x 2h. 556
Fig.2.2.32. Microstructures of cold-rolled Zr1Nb0.3Sn0.1Fe after various final annealing temperatures: (a) 500 ℃ x 2h, (b) 550 ℃ x 2h, (c) 600 ℃ x 2h, (d) 650 ℃ x 2h and (e) 680 ℃ x 2h. 557
Fig.2.2.33. Variation of hardness of Zr1Nb0.3Sn0.1Fe with annealing time at 500, 530 and 550 ℃. 558
Fig.2.2.34. Variation of hardness of Zr1Nb0.4Sn0.1Te with annealing time at 600 to 680 ℃.[원문불량;p.553] 0
Fig.2.2.35. Distribution of precipitates in Zr1Nb0.4Sn0.1Fe with final annealing temperatures of 550 to 680 ℃. 560
Fig.2.2.36. WDS of the matrix and a precipitate in Zr1Nb0.4Sn0.1Fe after annealing at 680 ℃ for 2h. 561
Fig.2.2.37. SADP of the matrix and the precipitate in a grainboundary in Zr1.0Nb0.4Sn0.1Fe after annealing at 680 ℃ for 2h. 562
Fig.2.2.38. Distribution of precipitates in Zr1Nb0.4Sn0.1Te with final annealing temperatures of 550 to 680 ℃. 563
Fig.2.2.39. WDS of the matrix and a precipitate in Zr1Nb0.4Sn0.1Te after annealing at 680 ℃ for 2h. 564
Fig.2.2.40. SADP of the matrix and the precipitate in the grainboundary in Zr1Nb0.4Sn0.1Te after annealing at 680 ℃ for 2h. 565
Fig.2.2.41. Variation of hardness of zirconium alloys with annealing time at 550 ℃ 566
Fig.2.2.42. Recrystallization behavior of zirconium alloys after annealing at 550 ℃ for 20h: A-1:Zr-1Nb-0.4Sn, A-2:Zr-1Nb-0.4Sn-0.3V, A-3:Zr-1Nb-0.4Sn-0.3Mo, A-4:Zr-1Nb-0.4Sn-0.1Fe 567
Fig.2.2.43. Variation of hardness of zirconium alloys with annealing time at 500 ℃ 568
Fig.2.2.44. Recrystallization behavior of zirconium alloys after annealing at 500 ℃ for 20h:A-1:Zr-1Nb-0.4Sn, A-2:Zr-1Nb-0.4Sn-0.3V, A-3:Zr-1Nb-0.4Sn-0.3Mo, A-4:Zr-1Nb-0.4Sn-0.1Fe 569
Fig.2.2.45. Distribution of Fe in the Zr-1.0Nb-0.4Sn-0.1Fe after annealing at 500 ℃ for 20 h (x5000) 570
Fig.2.3.1. Plasma Arc Remelting Equipment 571
Fig.2.3.2. Appearance of water-cooled mold and types of alloying elements 572
Fig.2.3.3. Microstructures of as-cast Zr-2.5Nb alloy 573
Fig.2.3.4. Appearances of specimen and forging die 574
Fig.2.3.5. Microstructure of as-forged Zr-2.5Nb alloy 575
Fig.2.3.6. Specimen appearance after cladding to minimize oxidation 576
Fig.2.3.7. Temperature variation with time during hot rolling process 577
Fig.2.3.8. Specimen appearance after decladding[원문불량;p.572] 578
Fig.2.3.9. Microstructures of experimental alloy after hot-rolling, cross sections normal to a) RD, b) ND and c) TD 579
Fig.2.3.10. Temperature variation with time during step cooling heat treatment 580
Fig.2.3.11. Schematic of ASTM E8 plate-type specimen in the early stages of tensile test(unit : mm) 581
Fig.2.3.12. Schematics of ASTM E8 subsize specimen mainly used for tensile test(unit : mm) (a) plate type with holes and (b)rod type 582
Fig.2.3.13. Microstructures and shape of as-cast Zr-1Nb-0.5Sn-xMo alloys. (a) 0.0Mo, (b) 0.2Mo, (c) 0.5Mo and (d) 0.7Mo 583
Fig.2.3.14. Microstructures and shape of as-forged Zr-1Nb-0.5Sn-xMo alloys. (a) 0.0Mo, (b) 0.2Mo, (c) 0.5Mo and (d) 0.7Mo 584
Fig.2.3.15. Micrographs of cold rolled Zr-1Nb-0.5Sn-xMO alloys. (a) 0.0Mo, (b) 0.2Mo, (c) 0.5Mo and (d) 0.7Mo 585
Fig.2.3.16. Micrographs of solution heat treated Zr 1Nb-0.5Sn-xMo alloys. (a) 0.0Mo, (b) 0.2Mo, (c) 0.5Mo and (d) 0.7Mo 586
Fig.2.3.17. Micrographs of Zr-1Nb-0.5Sn-0.5Mo alloy heat treated at 650 ℃ for (a) 1h., (b) 2h. and (c) 4h. 587
Fig.2.3.18. Micrographs of Zr-1Nb-0.5Sn-xMo alloys heat treated at 650℃ for 4h. (a) 0.2Mo, (b) 0.5Mo and (c) 0.7Mo 588
Fig.2.3.19. Variation of micrographs with furnace cooling time in step heat treated Zr-1Nb-0.5Sn-xMo alloys. (a) 5min., (b) 10min and (c) 20min. 589
Fig.2.3.20. XRD spectra of cold rolled Zr 1Nb-0.5Sn-xMo alloys 590
Fig.2.3.21. Variation of Kearns number of Zr-1Nb-0.5Sn-xMo alloys. 591
Fig.2.3.22. Variation of Kearns number(fn)(이미지참조) of Zr-1Nb-0.5Sn-xMo alloys with holding time at 650˚C. 592
Fig.2.3.23. Variation of Kearns number(fn)(이미지참조) of Zr-1Nb-0.5Sn-xMo alloys with furnace cooling time. 593
Fig.2.3.24. Variation of Kearns number(fn)(이미지참조) of Zr-1Nb-0.5Sn-xMo alloys in two different conditions. 594
Fig.2.3.25. Variation of Kearns number(fn)(이미지참조) of Zr-1Nb-0.5Sn-xMo alloys heat treated at 500 ℃. 595
Fig.2.3.26. Variation of hardness with fabrication route. 596
Fig.2.3.27. Variation of hardness Zr-1Nb-0.5Sn-xMo alloys with aging time. 597
Fig.2.3.28. Variation of yield strength with aging time. 598
Fig.2.3.29. Variation of ultimate tensile strength with aging time 599
Fig.2.3.30. Variation of elongation with aging time. 600
Fig.2.3.31. SEM fractographs of Zr-1Nb-0.5Sn-0.2Mo alloy with aging time, ruptured in tension at room temperature. (a) Oh., (b) 1h., (c) 4h and (d) 8h. 601
Fig.2.3.32. SEM fractographs of Zr-1Nb-0.5Sn-0.5Mo alloy with aging time, ruptured in tension at room temperature. (a) Oh., (b) 1h., (c) 4h and (d) 8h. 602
Fig.2.3.33. SEM fractographs of Zr-1Nb-0.5Sn-0.7Mo alloy with aging time, ruptured in tension at room temperature. (a) Oh., (b) 1h., (c) 4h and (d) 8h. 603
Fig 2.3.34. TEM views of aged Zr-1Nb-0.5Sn-xMo alloy for 4h. (a)0Mo, (b) 0.2Mo, (c) 0.5Mo and (d) 0.7Mo 604
Fig.2.3.35. TEM views of aged Zr-1Nb-0.5Sn-xMo alloy with aging time (a) Oh., (b) 1h., (c) 4h. and (d) 8h. 605
Fig.2.3.36. Diffraction pattern analysis of twin (a) SADP of (1011) and (b) indexing of (a)[원문불량;p.600] 606
Fig.2.3.37. Dark field image and SADP of Zr-1Nb-0.5Sn-0.5Mo alloy (a) dark field image, (b) SADP and indexing of (b)[원문불량;p.601] 607
Fig.2.3.38. TEM views of solution heat treated Zr-1Nb-0.5Sn-0.5Mo alloy (a) bright field image, (b) SADP and (c) indexing of (b)[원문불량;p.602] 608
Fig.2.3.39. Microstructures of Zr-1Nb-0.5Sn-0.5Mo alloy aged for (a) 1h and (b) 4h. 609
Fig.2.3.40. Phase diagram of Zr-Mo binary system. 610
Fig.2.3.41. Phase diagram of Zr-Mo-Sn ternary system at 500℃. 611
Fig.2.3.42. Microstructures of cold rolled experimental alloys. 612
Fig.2.3.43. Microstructures of stress relief annealed experimental alloys 615
Fig.2.3.44. Microstructures of experimental alloys annealed at 650 ℃. 618
Fig.2.3.45. Variation of hardness during RXA treatment of experimental alloys. 625
Fig.2.3.46. Microstructures of step heat treated experimental alloys. 628
Fig.2.3.47. Kearns numbers of cold rolled experimental alloys.[원문불량;p.631~633] 637
Fig.2.3.48. Kearns numbers of stress relief annealed experimental alloys. 640
Fig.2.3.49. Kearns numbers of recrystallization annealed experimental alloys. 643
Fig.2.3.50. Kearns numbers of step-heat treated alloys. 646
Fig.2.3.51. Volume fraction of phase in cold rolled experimental alloys. 649
Fig.2.3.52. Volume fraction of phase in stress relief annealed experimental alloys. 652
Fig.2.3.53. Volume fraction of phase in recrystallization annealed experimental alloys. 655
Fig.2.3.54. Volume fraction of phase in step-heat treated experimental alloys. 658
Fig.2.3.55. Tensile properties of cold rolled experimental alloys.[원문불량;p.655~657] 661
Fig.2.3.56. Tensile properties of stress relief annealed experimental alloys.[원문불량;p.658~660] 664
Fig.2.3.57. Tensile properties of recrystallization annealed experimental alloys. 667
Fig.2.3.58. SEM fractographs of Zr-1Nb-0.5Sn-xMo alloys ruptured in tension at room temperature. (a) 0.2Mo, (b) 0.5Mo (c) 0.7Mo 668
Fig.2.3.59. SEM fractographs of Zr-1Nb-xMo alloys ruptured in tension at room temperature (a) 0.0Mo, (b) 0.2Mo, (c) 0.5Mo and (d) 0.7Mo 669
Fig.2.3.60. SEM fractographs of (a) Zr-1Nb-0.5Cr-0.5Mo and Zr-0.5Nb-1.0Sn-xMo alloys ruptured in tension at room temperature (b) 0.2Mo, (c) 0.5Mo and (d) 0.7M 670
Fig.2.3.61. Variation of hardness with annealing temperature for 1h. (a) Zr-1Nb-0.5Sn-0.5Cr-xMo, (b) Zr-1Nb-xMo, (c)/((b)) Zr-1Nb-0.5Cr-0.5Mo-xSn and (d) Zr-0.5Nb-1Sn-xMo 671
Fig.2.3.62. Variation of hardness with annealing time at 700 ℃. (a) Zr-1Nb-0.5Sn-0.5Cr-xMo, (b) Zr-1Nb-xMo, (c)/((b)) Zr-1Nb-0.5Cr-0.5Mo-xSn and (d) Zr-0.5Nb-1Sn-xMo 672
Fig.2.3.63. Variation of hardness with annealing time at 650 ℃. (a) Zr-1Nb-0.5Sn-0.5Cr-xMo, (b) Zr-1Nb-xMo, (c)/((b)) Zr-1Nb-0.5Cr-0.5Mo-xSn and (d) Zr-0.5Nb-1Sn-xMo 673
Fig.2.3.64. Variation of hardness of Zr-1Nb-0.5Sn-0.5Cr-xMo alloys with annealing time at 450℃. 674
Fig.2.3.65. TEM views of cold rolled Zr-1Nb-0.5Sn-0.5Cr-xMo alloys (a) 0.2Mo, (b) 0.5Mo and (c) 0.7Mo 675
Fig.2.3.66. TEM views of Zr-1Nb-0.5Sn-0.5Cr-xMo alloys annealed at 450℃ for 1h. (a) 0.2Mo, (b) 0.5Mo and (c) 0.7Mo 676
Fig.2.3.67. TEM views of Zr-1Nb-0.5Sn-0.5Cr-0.7Mo alloys annealed at 550℃ for 1h. (a) spheroidal precipitates, (b) dislocation cell formation during annealing, (c)SADA of spheroidal precipitates and (d) indexing of (c) 677
Fig.2.3.68. Microstructures of Zr-1Nb-0.5Sn-0.5Cr-xMo alloys according to annealing condition. 678
Fig.2.3.69. TEM views of Zr-1Nb-0.5Sn-0.5Cr-xMo alloys annealed at 700℃ for 1h. (a) 0.2Mo, (b) 0.5Mo and (c) 0.7Mo 679
Fig.2.3.70. Optical microstructures and grain size distribution of Zr-1Nb-0.5Sn-0.5Cr-xMo alloys annealed at 800℃ for 1h. (a) 0.2Mo, (b) 0.5Mo and (c) 0.7Mo 680
Fig.2.3.71. Variation of tensile properties with annealing temperature. (for 1h.) 681
Fig.2.3.72. Scanning electron microscope fractographs of recrystallization annealed Zr-1Nb-0.5Sn-0.5Cr-xMo alloys ruptured at room temperature. (a) 0.2Mo, (b) 0.5Mo and (c) 0.7Mo 682
Fig.2.3.73. Microstructure of (a) hot rolled and (b) cold rolled Zr-1.0Nb-1.0Sn-0.5Mo alloy 683
Fig.2.3.74. Microstructure of Zr-1.0Nb-1.0Sn and Zr-l.0Nb-1.0Sn-0.5Mo alloy after recrystallization annealing (650℃/5h.) 684
Fig.2.3.75. Microstructure of recrystallization annealed Zr-1.0Nb-1.0Sn 685
Fig.2.3.76. Microstructure of recrystallization annealed Zr-1.0Nb-1.0Sn-0.5Mo alloy. 686
Fig.2.3.77. Dislocation structure of Zr-1.0Nb-1.0Sn-0.5Mo alloy showing sub-grain formation during recrystallization annealing (700℃/5h.) 687
Fig.2.3.78. Precipitates in Zr-1.0Nb-1.0Sn alloy heat treated at 700℃ for 5h. 688
Fig.2.3.79. Variation of the volume and size of precipitates in Zr-1.0Nb-1.0Sn alloy during recrystallization heat treatment. 689
Fig.2.3.80. Grain growth characteristics of Zr-1Nb-1Sn alloy and Zr-1Nb-1Sn-0.5Mo alloys during recrystallization heat treatment. 690
Fig.2.3.81. Effect of recrystallization heat treatment on the transverse basal texture(ft)(이미지참조) of Zr-1.0Nb-1.0Sn alloy. 691
Fig.2.3.82. Effect of recrystallization heat treatment on the normal basal texture(fn)(이미지참조) of Zr-1.0Nb-1.0Sn alloy. 692
Fig.2.3.83. Effect of recrystallization heat treatment on the normal basal texture(fn)(이미지참조) of Zr-1.0Nb-1.0Sn-0.5Mo alloy. 693
Fig.2.3.84. Effect of recrystallization heat treatment on the transverse basal texture(ft)(이미지참조) of Zr-1.0Nb-1.0Sn-0.5Mo alloy. 694
Fig.2.3.85. Basal (0002) pole figure of Zr-1.0Nb-1.0Sn-0.5Mo alloy. (a) as-rolled, (b) heat treated at 700oC for 3h., (c) 4h. and (d) 5h 695
Fig.2.3.86. CODF map of recrystallization heat treated( 700℃, 3h.) Zr-1.0Nb-1.0Sn-0.5Mo alloy. 696
Fig.2.3.87. CODF map at Ø=0 of recrystallization heat treated ( 700℃, 3h.) Zr-1.0Nb-1.0Sn-0.5Mo alloy. 697
Fig.2.3.88. Effect of recrystallization heat treatment on the amount of β-phase in experimental Zr-alloys. 698
Fig.2.3.89. Sectioning direction of tensile specimens. 699
Fig.2.3.90. Variation of yield strength of Zr-1.0Nb-1.0Sn-0.5Mo alloy with sectioning direction. 700
Fig.2.3.91. Effect of recrystallization heat treatment on micro-hardness of Zr-1.0Nb-1.0Sn alloy. 701
Fig.2.3.92. Effect of recrystallization heat treatment on micro-hardness of Zr-1.0Nb-1.0Sn-0.5Mo alloy. 702
Fig.2.3.93. Fabrication route of the experimental alloys. 703
Fig.2.3.94. Schematic drawing of plasma arc remelting epuipment 704
Fig.2.3.95. Melting route for experimental alloys. 705
Fig.2.3.96. Microstructures of Zr-1Nb-0.5Mo alloy. (a) as-cast, (b) forged and (c) β-quenched 706
Fig.2.3.97. Variation of temperature with time during step-heat treatment 707
Fig.2.3.98. Variation of microstructure of Zr-1Nb-0.5Mo alloy with temperature during step heat treatment. (a) 980℃, (b) 970℃, (c) 960℃, (d) 950℃, (e) 850℃ and (f) 750℃ 708
Fig.2.3.99. Differential thermal analysis for Zr-1Nb-0.5Mo alloy. 709
Fig.2.3.100. Temperature variation with time during hot rolling. 710
Fig.2.3.101. Variation of microstructure of Zr-1Nb-0.5Mo alloy with hot rolling temperatures. (a) 750℃, (b) 850℃, (c) 950℃ 711
Fig.2.3.102. TEM micrographs of Zr-1Nb-0.5Mo alloy hot rolled at 750℃ (a) elongated grains and subgrains and (b) equiaxed grains 712
Fig.2.3.103. TEM micrographs of Zr-1Nb-0.5Mo alloy hot rolled at (a) 850℃ and (b) 950℃, (c) magnified (b), (d) SADP of twin 713
Fig.2.3.104. Comparison of tensile properties of hot rolled experimental alloys. 714
Fig.2.3.105. SEM fractographs of Zr-1Nb-0.5Mo alloy hot rolled at (a) 750℃,(b) 850℃ and (c) 950℃ and Zr-2.5Nb hot rolled at 850℃ 715
Fig.2.3.106. Stress-strain curve and microstructure variation with elongation. 716
Fig.2.3.107. Variation of hardness with aging temperatures for previously hot rolled Zr-1Nb-0.5Mo alloy. 717
Fig.2.3.108. Variation of hardness with aging time at 450℃ (a) Zr-1Nb-0.5Cr-0.5Mo (b)Zr-1Nb-1Sn-0.5Mo and (c) Zr-1Nb-0.5Sn-0.5Cr-0.5Mo 718
Fig.2.3.109. Tensile properties of experimental alloys aged at 450℃ for 1h. 719
Fig.2.3.110. TEM micrographs of aged Zr-1Nb-0.5Mo alloy.(a) precipitate at grain boundaries, (b, c) precipitates within and at grain boundaries. (d) dark field image, (e) SADP of precipitate and (f) EDX analysis 720
Fig.2.3.111. Variation of tensile properties with cold rolling reduction. 721
Fig.2.3.112. Tensile properties of experimental alloys tested at room temperature and 300℃ 722
Fig.2.3.113. Creep strain of Zr-1Nb-0.5Mo alloys with time at 400℃ 723
Fig.2.3.114. Strain rate of Zr-1Nb-0.5Mo alloys at 400℃ under the tension of 150MPa 724
Fig.3.1. Manufacturing procedure of yttria stabilized zirconia Sol. 725
Fig.3.2. Flow sheet of Experimental procedure 726
Fig.3.3. XRD pattern of Zr(OH)₄after drying at 60℃ 727
Fig.3.4. Microstructure of the Zr(OH)₄ powder after drying at 60℃ 728
Fig.3.5. XRD patterns of ZrO₂ powders after hydrothermal treatment at 250℃ for 6h with various pH values in LiOH solutions: a) pH=7.00, b) pH=10.01, c) pH=11.31, d) pH=12.24 and e) pH=12.32 729
Fig.3.6. XRD patterns of ZrO₂ powders after hydrothermal treatment at 250℃ for 6h with various pH values in NaOH solutions: a) pH=7.00, b) pH=10.01, c) pH=11.32, d) pH=12.20 and e) pH=12.52 730
Fig.3.7. XRD patterns of ZrO₂ powders after hydrothermal treatment at 250℃ for 6h with various pH values in KOH solutions: a) pH=7.00, b) pH=9.96, c) pH=11.48, d) pH=12.16 and e) pH=12.46 731
Fig.3.8. Fraction of m-ZrO₂ after hydrothermal annealing at 250℃ for 6h with various pH values in alkaline solutions 732
Fig.3.9. Shape of zirconia precipitates after hydrothermal treatment at 250℃ for 0h in various solutions; (a)water, (b) LiOH, (c) NaOH and (d) KOH 733