Authors: Daisuke Kobayashi Masamichi Miyabe Yukio Kagiya Ryuji Sugiura A Toshimitsu Yokobori
Publish Date: 2013/03/16
Volume: 44, Issue: 7, Pages: 3123-3135
Abstract
In order to characterize the damage progression behavior of IN738LC and the influence of applied stress the average misorientation within grains was evaluated using the electron backscattered diffraction EBSD method by measuring over a million data points located across almost the whole zone of the tested specimens It has been shown under various test conditions such as differing temperatures and strain rates that the average misorientation increases linearly with the increase of creep strains As a result it is confirmed that it is possible to assess the remaining creep fracture life from its average misorientation value regardless of the testing temperature and strain rate In addition the deformation and fracture mechanisms of various types of mechanical damage such as tensile impact and creep conditions were discussed by evaluating the characteristics of misorientation distribution As a result it has been revealed that creep damage affects a large area of the material but it is localized near grain boundaries which is completely different from that of tensile or impact damage In conclusion detailed investigation into the cross section of fracture samples using the EBSD misorientation analysis allows for the qualitative estimation of the fracture mode under various applied stress conditions the cause of the fracture
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