本文主要是利用霍普金森扭轉試驗機來研究316L不銹鋼在動態剪切荷載下之塑性變形與破壞行為。扭轉試片分別於溫度-150℃ 、25℃ 、300℃及應變速率1×103 s-1、2×103 s-1、3×103 s-1條件下進行剪切變形測試。藉由巨觀性質、微觀結構與破壞特性來探討應變與應變速率對316L不銹鋼動態剪切塑變行為之影響；同時引用一構成方程式來描述其於高速剪切行為與特性。
實驗結果顯示316L不銹鋼機械性質受剪應變速率、溫度及剪應變量之影響甚鉅，在固定溫度條件下，其塑流剪應力值、破壞剪應變量、加工硬化率、降伏剪強度、加工硬化係數、應變速率敏感性係數與溫度敏感性係數皆會隨著剪應變速率的提升而增加，而活化能則隨應變速率增加而減少；另外，在固定剪應變速率條件下，其塑流剪應力值、加工硬化率、降伏剪強度、加工硬化係數、應變速率敏感性係數、與溫度敏感性係數皆會隨著測試溫度的提高而下降，而破壞剪應變量與活化能則隨著溫度的提高而增加。藉由Kobayashi & Dodd模式之構成方程式能準確地描述316L不銹鋼在不同溫度及應變速率下的變形行為。在微觀結構方面，利用掃描式電子顯微鏡(SEM)與光學顯微鏡(OM)進行之破壞形貌與金相組織分析顯示，破斷面韌窩組織隨應變速率與溫度的提高而有越密的趨勢；而破斷區域之金相組織顯示，剪斷區附近之晶粒流線角度，隨溫度與應變速率的增加也有上升的趨勢。塑變區之硬度值隨著應變速率上升而增加，但隨著溫度與遠離剪切帶的距離增加而有降低的現象。

The dynamic shear deformation behaviour and fracture characteristics of 316L stainless steel are investigated by using a split-Hopkinson torsional bar system. Shear deformation is conducted at temperatures of -150℃, 25℃ and 300℃ under strain rates ranging from 1×103s-1 to 3×103s-1, respectively.The experimental results indicate that the shear flow response is found to be sensitive to the strain, strain rate and temperature. The flow stress, fracture strain, work hardening rate, yielding strength, work hardening coefficient, strain rate sensitivity all increase with the increasing strain rate for a fixed temperature, but decrease with the increasing temperature under a constant strain rate. The inverse tendency is observed for activation energy. The observed high strain rate shear deformation behaviour of 316L stainless steel can be described using the Kobayashi and Dodd constitutive equation. From the SEM observations, it is found that the fracture surfaces are characterized by a dimple-like structure, which is indicative of a ductile failure mode. The morphology and the density of these dimples are influenced greatly by strain rate and temperature conditions. Optical microscopy observations reveal that grain of the fracture surfaces are twisted into band-like features. The microhardness of these shear bands increases with the strain rate, but decreases with the temperature as a result of different work hardening effects.

參考文獻
1. H. Kolsky, "An Investingaation of The Mechanical Properties of Materials at Very High Rates of Loading", Proceedings of the Physical Society, Vol. 62, pp. 676-699, 1949.
2. B. M. Butcher and C. H, Karnes, "Strain Rate Effects In Metals", Journal of Applied Physics, Vol. 37, pp. 402-411, 1964.
3. F. E. Hauser, "Techniques for Measuring Stress-Strain Relations at High Strain Rates", Experimental Mechanics, Vol. 6, pp. 395-402, 1966.
4. Y. Leroy and M. Ortiz, In Mechanical Properties of Materials at High Rate of Strain, (ed. J. Harding), pp. 257-265, 1989.
5. D. J. Steinberg, S. G. Cochran and N. W. Guinan, "A Constitutive Model for Metals Applicable at High Strain Rate", Journal of Applied Physics, Vol. 51, No.3, pp. 1498-1504, 1980.
6. Ludwik and Z. Vereins Deut. Ing., 71, pp. 1532-1538, 1927.
7. H. Kobayashi and B. Dodd, "A Numerical Analysis for the Formation of Adiabatic Shear Bands Including Void Nucleation and Growth," International Journal of Impact Engineering, Vol. 8, pp. 1-13, 1989.
8. 黃振賢，機械材料，文京圖書有限公司，頁234-244，民國八十九年。
9. M. A. Meyers and L. E. Murr, Shock Waves and High-Strain-Rate Phenomena in Metals, Plenum Press, pp. 129-167, 1981.
10. ASM Handbook Committee, Metals Handbook, American Society for Metals, pp. 215-230, 1978.
11. U. S. Lindholm and L. W. Yeakly, “High Strain Rate Testing: Tension and Compression,” Experimental Mechanics, Vol. 3, pp. 81-88, 1983.
12. M. A. Meyers, Dynamic Behavior of Materials, A Wiley-Interscience Publication, pp. 23-65, 1994.
13. J. D. Campbell, “Dynamic Plasticity: Macroscopic and Microscopic Aspects,” Materials Science and Science Engineering, Vol. 12, pp. 3-21, 1973.
14. D. Klahn, A. K. Mukherjee and J. E. Dorn, Proceedings of the 2nd International Conference on the Strength of Metals and Alloys, Vol. III, ASM, pp. 951, 1970.
15. J. D. Campbell and W. G. Ferguson, “The Temperature and Strain-Rate Dependence of the Shear Strength of Mild Steel,” The Philosophical Magazine, Vol. 21, pp. 63-82, 1970.
16. A. M. Eleiche and J. D. Campbell, “Strain-Rate Effects During Reverse Torsional Shear,” Experimental Mechanics, Vol. 16, pp. 281-290, 1976.
17. J. Harding and J. Huddart, “The Use of the Double-Notch Shear Test in Determining the Mechanical Properties of Uranium at Very High Rates of Strain,” Proc. 2nd Conf. Mechanical Properties of Materials at High Rates of Strain, Inst. Physics, pp. 49-61, 1980.
18. A. Seeger, “The Generation of Lattice Defects by Moving Dislocations, and its Application to the Temperature Dependence of the Flow-Stress of FCC Crystals,” The Philosophical Magazine, Vol. 46, pp. 1194-1217, 1955.
19. U. S. Lindholm and L. M. Yeakly, “Dynamic Deformation of Single and Polycrystalline Aluminum,” Journal of Mechanics and Physics of Solids, Vol. 13, pp. 41-49, 1965.
20. H. Conrad, “Thermally Activated Deformation of Metals,” Journal of Metals, pp. 582-588, 1964.
21. W. G. Ferguson, A. Kumar and J. E. Dorn, “Dislocation Damping in Aluminum at High Strain Rates,” Journal of Applied Physics, Vol. 38, pp. 1863-1869, 1967.
22. J. D. Campbell and A. R. Dowling, “The Behaviour of Materials Subjected to Dynamic Incremental Shear Loading,” Journal of Mechanics and Physics of Solids, Vol. 18, pp. 43-63, 1970.
23. J. Harding, “The Effect of High Strain Rate on Material Properties,” Materials at High Strain Rate on Material Properties, pp. 133-186, 1987.
24. Y. Bai and B. Dodd, Adiabatic Shear Localization, Pergamon Press, pp. 104-124, 1992.
25. J. D. Campbell, A. M. Eleiche, and M. C. C. Tsao, Fundamental Aspects of Structural Alloy Design, Plenum Publishing Corp. New York, pp. 545-563, 1977.
26. R. W. Klopp, R. J. Clifton and T. G. Shawki, “Pressure Shear Impact and Dynamic Viscoplastic Response of Metals,” Mechanics of Materials, Vol. 4, pp. 375-385, 1985.
27. F. J. Zerilli and R. W. Armstrong, “Dislocation-Mechanics-Based Constitutive Relations for Material Dynamics Calculations,” Journal of Applied Physics, Vol. 61, pp. 1816-1825, 1987.
28. F. J. Zerilli and R. W. Armstrong, “Constitutive Equation for HCP Metals and High Strength Alloy Steels, in High Strain Rate Effects on Polymer, Metal and Ceramic Matrix Composites and other Advanced Materials, ”AD-Vol. 48, pp. 121-126, 1995.
29. A. S. Khan and H. Zhang, “Mechanically Alloyed Nanocrystalline Iron and Copper Mixture: Behavior and Constitutive Modeling over a Wide Range of Strain Rates,” International Journal of Plasticity, Vol. 16, pp. 1477-1492, 2000.
30. R. Liang and A. S. Khan, “A Critical Review of Experimental Results and Constitutive Models for BCC and FCC Metals over a Wide Range of Strain Rates and Temperatures,” International Journal of Plasticity, Vol. 15, pp. 963-980, 1999.
31. L. Shi and D. O. Northwood, “The Mechanical Behavior of an AISI Type 310 Stainless Steel,” Acta Metallurgica et Materialia, Vol. 43, pp. 453-460, 1995.
32. Lars-Erik Lindgren, Konstantin Domkin and Sofia Hansson, “Dislocations, vacancies and solute diffusion in physical based plasticity model for AISI 316L,” Mechanics of Materials, Vol. 40, pp. 907-919, 2008.
33. Howard E. Boyer and Timothy L. Gall,Metals Handbook, Eds., American Society for Metals, Materials Park, OH, 1985.
34. Philip D. Harvey, editor,Engineering Properties of Steels, American Society for Metals, Metals Park, OH, (1982).
35. Shih-Chieh Liao and J. Duffy, “Adiabatic shear bands in a Ti-6Al-4V titanium alloy,” Pergamon Press, Vol. 46, pp. 2201-2231,1998.
36. U. Andrade, M. A. Meyers, K. S. Vecchio and A. H. Chokshi, “Dynamic Recrystallization in High-Strain, High-Strain-Rate Plastic Deformation of Copper,” Pergamon Press, Vol. 42, No.9, pp. 3183-3195,1994.
37. R. Kapoor and S. Nemat-Nasser, “Determination of Temperature Rise during High Strain Rate Deformation,” Mechanics of Materials, Vol. 27, pp. 1-12, 1998.
38. Y. B. Xu, W. L. Zhong, Y. J. Chen, L. T. Shen, Q. Liu, Y. L. Bai and M. A. Meyers, “Shear Localization and Recrystallization in Dynamic Deformation of 8090Al-Li Alloy,” Materials Science and Engineering. A, 299, pp. 287-295, 2001.
39. 李南瑋,“生醫鈦合金之動態剪切變形與破壞行為分析”國立成功大學機械工程研究所碩士論文,2007.
40. 劉家銘,“304不銹鋼在動態剪切荷載下的塑變行為與顯微結構特性分析”國立成功大學機械工程研究所碩士論文,2001.
41. 龔虔稽,“溫度及應變速率在非可銲性鋁鈧合金動態剪切性能上之效應分析”國立成功大學機械工程研究所碩士論文,2006.