Characterizing Fatigue Fractures in EB Welded Gas Turbine Materials

This book compiles two complete case studies of characterizing fatigue failure initiation in two of the most commonly employed materials for gas turbine compressor disks, i.e., Waspaloy and Inconel 718. The book covers relevant literature on the subject and presents, in full details, the complete stages of microstructural characterization of base metal and weld metal (for both full penetration and partial penetration electron-beam welds). These two studies clearly relate modifications in microstructures to the resulting deficient fatigue strength in the welded components and demonstrates the effects of welding cycles in promoting such fatigue-strength deficient microstructure. Experimentally proven alternative welding procedures are suggested for improved fatigue initiation resistance.The book also provides valuable supporting information about procedures for accurate microstructural characterization including SEM, TEM and XRD and also on interpreting fracture surfaces of failed samples.The present book is considered to be a highly valuable and essential reference for engineers and researchers working in the areas of failure analysis, gas turbines and high-temperature alloys.