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研究生： 阮友嚴
Nghiem, Nguyen Huu
論文名稱： A533 與A572 異材銲接製程之Nd-YAG 雷射銲接特性研究
Application of Laser Beam Welding on Dissimilar Weld A533 to A572
指導教授： 李驊登
Lee, Hwa-Teng
學位類別： 碩士
Master
系所名稱： 工學院 - 機械工程學系
Department of Mechanical Engineering
論文出版年： 2010
畢業學年度： 98
語文別： 英文
論文頁數： 87
中文關鍵詞： 異種銲接 、A533 、雷射銲接 、熱影響區 、殘留應力
外文關鍵詞： Dissimilar weld, A533, Laser Beam Welding, HAZ, Residual Stress
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    • ASTM A533 合金鋼為核電廠之壓力容器之主要鋼材。異材銲接多使用在壓力容器、壓縮機及蒸氣機上以降低成本。相較於遮蔽金屬棒電弧銲（SMAW）及惰性氣體鎢棒電弧銲(GTAW)等傳統銲接，雷射銲接具有更多優點。因其具有高強度熱源，可以克服異種材料間熱傳導差異之問題。雷射銲接穿透模透式可以形成相當窄的銲道及熱影響區並減少熱扭曲、有效的減低殘留應力及改善銲接料的冶金性質。
    本研究選用ASTM A533 TypeB Class2 與A572 Grade 65鋼板，板材厚度為3mm，並採用Nd-YAG雷射銲接製程對兩種材進行異材對接。並觀察不同雷射銲接參數對銲件的微結構組職、機械性質及殘留應力值的影響。實驗結果顯示當熱影響區的冷卻速率在115℃及170 ℃間，重融區、粗晶及細晶區的組職皆有麻田散鐵形成。拉伸試驗的結果則斷裂處產生在A572母材處，拉伸強度為83.76 ksi。此結果顯示藉由雷射銲接，其銲接處之強度高於A572母材強度。雷射銲接也形成較窄之熱影響區，其寬度約在1.4mm，此區域形成殘留應力雖高於傳統銲接製程，但銲道並無因殘留應力而導致拉生斷口發生在銲道處，仍符合使用上的安全需求。

    The A533 and A572 low alloy steels are key materials which have been used in nuclear reactor facilities, such as pressure vessel, compressor, and stream generator where dissimilar welding is commonly employed with an aim to save cost. Meanwhile Laser Beam Welding (LBW) has many advantages in comparison with conventional welding techniques such as Shield Metal Arc Welding (SMAW) and Gas Tungsten Arc Welding (GTAW). With its high intensity heat source, LBW is able to overcome differences in thermal conductivity problems between different materials. Penetration mode of laser beam welding can produce a narrow weld bead with a narrow Heat Affected Zone (HAZ) which limits thermal distortion, reduce effectively residual stress and improve metallurgical properties of welded metal.
    In this study, dissimilar welding of ASTM A533 Type B Class 2 to A572 Grade 65 was carried out with Nd – YAG Laser Beam Welding. Microstructure, mechanical properties as well as residual stress adjacent to the weld were studied after butt welding. Experimental results show that with the cooling rate of 115 0C/s-170 0C/s in HAZ, martensite is formed in the fusion zone, coarse and fine grains in Heat Affected Zone. The welded structure fabricated by LBW has a much higher hardness than that done by conventional welding. Hardness increases rapidly from base metal to Heat Affected Zone. Tensile tests revealed that fracture occurred at base metal of A572 by 83.76 Ksi. It demonstrated that strength of dissimilar weld joint is higher than the base metal and satisfied the safety requirement during operating. Meanwhile Laser beam welding makes a narrow Heat Affected Zone which is about 1.4 mm in comparison with 2 to 2.5 mm HAZ done by Shield Metal Arc Welding. And the residual stress in this area was formed.

    摘要 I Abstract II Acknowledgement III List of figures VII List of tables X Chapter 1: Introduction. 1 Chapter 2: Theories and Literature review. 6 2.1. Welding [18, 19, 9, 12] 6 2.2. Advantages of Laser beam welding. 9 2.3. Welding heat affected zone 13 2.3.1. Weld 13 2.3.2. Heat affected zone. 14 2.4. Residual stress formed in single pass weld [6, 16, 17, 19] 17 2.5 Hole-Drilling Strain-Gage Method 20 2.5.1 Theoretical description [6, 25] 20 2.5.2. ASTM Standard E837 [21] 26 Chapter 3: Welding materials and experimental procedure 34 3.1. Experimental planning 34 3.2. Experimental workflow 35 3.2.1 Materials’ composition and specification 35 3.2.2. Laser beam welding. 38 3.2.3. Metallography preparation. 42 3.2.4. Microscopic analysis 42 3.2.5. Thermal history. 42 3.2.6. High speed drilling strain gage [21] 43 3.2.7. Vickers hardness test 43 3.2.8. Tensile test 44 3.2.9. Fracture analysis 44 3.3. Instruments and equipments 45 Chapter 4: Experimental results and Discussion 54 4.1 A533 and A572 base metal 54 4.2 Bead on plate result 57 4.2.1. BOP with A533 low alloy steel 58 4.2.2 BOP with High strength low alloy steel A572 60 4.3. Microstructure of dissimilar weld A533 to A572 61 4.3.1. A533 and A572’s continuous cooling transformation 61 4.3.2. Dissimilar weld A533 to A572 heat affected zone 63 4.3.3. Cooling rate and thermal history 70 4.4. Hardness 72 4.5. Residual stress 75 4.6. Tensile tests 79 4.7. Fracture surface analysis 81 Chapter 5: Conclusions 83 Chapter 6: Suggestions and future works 84 References: 85

    1. Z. Sun, J. C. Ion. “Review Laser Welding of dissimilar metal combinations”. Journal of Materials Science Vol 30, pp. 4205-4214, 1995.
    2. K. Poorhaydari, B. M Parchett, and D.G. Ivey. "Estimation of cooling rate in the welding of plates with intermediate thickness," Welding Journal 84(10), pp. 149-s - 155-s, 2005.
    3. H. T. Kou, R. C. Wei. W. F. Wu, J. R. Yang. “Simulated heat affected zone in ASTM A533-B steel plates under low heat inputs”. Materials Chemistry and Physics 117, pp. 471-477, 2009.
    4. H.T Lee and J.L Wu. “Correlation between corrosion resistance properties and thermal cycles experienced by gas tungsten arc welding and laser beam welding alloy 690 butt weldments”. Corrosion Science 51 pp. 733-743, 2009.
    5. J. R. Yang and S. H. Liou. “Microstructural evolution of simulated heat affected zone in ASTM A533 type B steel plates”. Science and Technology of Welding and Joining Vol. 2 No.3, pp. 119-127, 1997.
    6. Fu-Chuan Hsu. “Feasibility study and evaluation of applying EDM Hole-Drilling Method for measuring residual stress”. Doctoral Thesis, Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan, 2005.
    7. Chen-Ching Lai. “Characteristic study of dissimilar welding of A533 to A572 alloy”. Master Thesis, Department of Mechanical Engineering, National
    Cheng Kung University, Tainan, Taiwan, 2005.
    8. S. Kim, S. Lee, Y.R Im, H.C Lee, Y. Oh, Hong, “Effects of Alloying Elements on Mechanical and Fracture Properties of Base Metals and Simulated Heat-Affected Zones of SA 508 Steels”. Volume 32, Number 4, pp. 903-911. Jun 2001,
    9. S. Missori, G. Costanza, E. Tata, A. Sili, “Laser beam welding of quenched and tempered ASTM A 517 GR.B steel”, Proceeding of the Super High Strength Steel 1st Conference, Rome, 2-4 November 2005.
    10. Kou, T. Y., and S. L. Jeng. "Porosity Reduction in Nd–YAG Laser Welding of Stainless Steel and Inconel Alloy by using a Pulsed Wave", Journal of Physics D: Applied Physics, 38, pp. 722-728, 2005.
    11. H.T Lee, J.L Wu. “Intergranular corrosion resistance of nickel-based alloy 690 weldments”. Corrosion Science Volume 52, Issue 5, Pp, 1545-1550, 2010.
    12. Olson, D. L. et al. “Welding, Brazing, and Soldering”. ASM Handbook Vol. 6. ASM International, 1993.
    13. O. Perret, P. Naudy, and M. Bizouard. “Keyhole Formation Study in Pulse Nd:YAG Laser Welding”, in Proceedings of the Laser Materials Processing Conference ICALEO 1999. San Diego, CA, pp. D177-D186, 2000.
    14. H.T Lee, and J. L. Wu. "The Effects of Peark Temperature and Cooling Rate on the Susceptibility to Intergranular Corrosion of Alloy 690 by Laser Beam and Gas Tungsten Arc Welding," Corrosion Science, 51(3), pp. 439-445,2009.
    15. John C. Ion. “Laser processing of engineering materials: principles, procedure and industrial application”. Butterworth-Heinemann, Boston, 2005.
    16. “Welding Handbook”, 7th edition, Vol. 1, 1976, Miami, American Welding.
    17. Kenneth Easterling (1992). “Introduction to the Physical Metallurgy of Welding”. Butterworth Heinemann, Boston.
    18. Walter W. Duley (1999). “Laser Welding”. Wiley, New York
    19. Kou, S. (1987). “Welding metallurgy”. Wiley, New York.
    20. W.C Fan. “The influence of Nd-YAG Laser welding parameters on dissimilar welding of Alloy 690 and 304 stainless steel”. Master Thesis, Department of Mechanical Engineering, NationalCheng Kung University, Tainan, Taiwan, 2005.
    21. ASTM standard E837-01 (2001). “Standard Test Method for Determining Residual Stresses by ther Hole Drilling Strain Gage method”. ASTM, Philadelphia, PA.
    22. USA Plate Information. “Plate Steel Specification Guide”, 2010 http://www.arcelormittal.com/plateinformation/documents/en/Inlandflats/ProductSpecification/2010%20SPEC.%20GUIDE%20%20FINAL%20WEB%20VERSION.pdf
    23. ASTM A533/A 533M-93, ”Standard Specification for Pressure Vessel plates, Alloy Steel, Quenched and Tempered, Manganese-Molybdenum and Manganese-Molybdenum-Nickel”, 1999.
    24. A572/A572M-03a, “Standard Specification for High-Strength Low-Alloy Columbium-Vanadium Structural Steel”, 2003.
    25. Measurements Group, “Technical Note TN 503”, Measurement of Residual Stresses by the Hole-Drilling Strain Gage Method, www.vishay.com/brands/measurements_group/guide/tn/tn503/
    26. M. Kabiri, “Measurement of Residual Stress by the Hole-Drilling Method: Influenceof Transverse Sensitivity of the Gages and Relieved Strain Coefficients”, Experimental Mechanics, pp. 252-256, 1984.
    27. Jose Roberto Berretta, Wagner de Rossi. “Pulsed Nd:YAG laser welding of AISI 304 to AISI 420 stainless steels”, Optics and Lasers in Engineering 459, pp. 60-966. (2007).
    28. "Nuclear Power Plants Information. Number of Reactors Operation Worldwide". International Atomic Energy Agency.
    http://www.iaea.org/cgi-bin/db.page.pl/pris.oprconst.htm. Retrieved 2008-06-21.
    29. “Assessment and Management of Ageing of Major Nuclear Power Plant Components Important to Safety: PWR Pressure Vessels”: International atomic energy agency 2007.
    30. U.S. Nuclear Regulatory Commission, Nuclear reactors. http://www.nrc.gov/reading-rm/basic-ref/students/reactors.html

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