Preface Acknowledgments 1. Introduction 2. Dispersion principles 3. Unbounded isotropic and anisotropic media 4. Reflection and refraction 5. Oblique incidence 6. Waves in plates 7. Surface and subsurface waves 8. Finite element method for guided wave mechanics 9. The semi-analytical finite element method (SAFE) 10. Guided waves in hollow cylinders 11. Circumferential guided waves 12. Guided waves in layered structures 13. Source influence on guided wave excitation 14. Horizontal shear 15. Guided waves in anisotropic media 16. Guided wave phased arrays in piping 17. Guided waves in viscoelastic media 18. Ultrasonic vibrations 19. Guided wave array transducers 20. Introduction to guided wave nonlinear methods 21. Guided wave imaging methods Appendix A: ultrasonic nondestructive testing principles, analysis and display technology Appendix B: basic formulas and concepts in the theory of elasticity Appendix C: physically based signal processing concepts for guided waves Appendix D: guided wave mode and frequency selection tips.

Ultrasonic Guided Waves in Solid Media

Present Status of Vanadium Alloys for Fusion Applications

At moderately high temperature sections of Advanced Ultra Super Critical (AUSC) boilers, welding of superalloys to austenitic steels is inevitable owing to economic aspects of boiler. Welding of SUS 304H and Inconel 617 (IN 617) was attempted using IN 617 filler material employing conventional Gas Tungsten Arc Welding (GTAW) process and the procedure was successfully established along with optimized welding parameters. Microstructural characterization was carried out to identify various zones on either side of the fusion boundaries. Unmixed Zone and Heat Affected Zone (HAZ) were observed towards SUS 304H fusion boundary while no distinct HAZ was observed towards IN 617 fusion boundary. Micro-hardness profiling indicated decrease in hardness at the HAZ towards SUS 304H fusion boundary. Mechanical properties evaluation at both ambient and elevated temperatures was carried out and data obtained was compared with those of base metals. The tensile strength of the cross weld specimens at high temperatures were observed to be marginally lower than that of IN 617 but significantly more than that of SUS 304H, hence, tolerable. Stress-rupture properties of the cross-weld specimens as tested in this study were found to be intermediate to the base metals’ data, thus, suitable for AUSC power plants' boiler applications. Hence, this work gives an insight into welding procedure establishment, microstructural development, variation of mechanical properties at elevated temperatures and stress-rupture properties of the dissimilar metal welds at elevated temperatures.

Development and evaluation of SUS 304H — IN 617 welds for advanced ultra supercritical boiler applications

Tensile deformation behavior and microstructure evolution of Ni-based superalloy 617

The microstructure evolutions of Ni–Cr–W based superalloy during thermal exposure have been investigated systematically. M 6 C carbides in the alloy decompose into M 23 C 6 carbides at temperatures from 650 to 1000 °C due to its high content of Cr. The M 6 C carbides decompose dramatically from 800 to 900 °C. At temperatures up to 1000 °C, a few M 23 C 6 carbides form on the surface of M 6 C carbides. The decomposition behavior of primary M 6 C can be explained by the following reaction: M 6 C → M 23 C 6  + Me (W, Ni, Cr, Mo). At temperatures below 900 °C, coarse lamellar M 23 C 6 carbides precipitate at the grain boundaries. The carbide lamellae line almost perpendicular to the grain boundaries. While the temperature is above 1000 °C, discrete M 23 C 6 carbides precipitate at the grain boundaries. Moreover, there are lots of small M 23 C 6 particles precipitated around M 6 C carbides from 650 to 1000 °C.

Effect of thermal exposure on the stability of carbides in Ni–Cr–W based superalloy

https://oatao.univ-toulouse.fr/4705/1/Chomette_4705.pdf

Jean-Marie Gentzbittel

Papers

Creep behaviour of as received, aged and cold worked INCONEL 617 at 850 °C and 950 °C

Assessment of a European V–4Cr–4Ti alloy – CEA-J57