Study on the high-temperteraure tensile property and damage behavior in GH4141 superalloy
This study focuses on the tensile properties of GH4141 superalloy tested at room temperat-ure,300 ℃ and 500 ℃,respectively.The tensile strength obtained at high temperatures of 300 ℃ and 500 ℃ with serrated stress-strain curves are lower than that obtained at room temperature.In addition,the tensile strength tested at 500 ℃ is comparable to the value achieved at 300 ℃.The microstructure near the fracture surface of the superalloy is characterized.It is showed that cracks are formed at the grain boundary,irrespective of the observation of MC type carbides.The carbide composed of M6C and M23C6 with chain morphology endows grain boundary with a good plasticity which is reflected by nu-merous dimples in the fractographs.The initiation of cracks within the grains is associated with forma-tion of slip bands.The activation of slip band can be delayed by dislocation pinning effect related to the interstitial elements,substituted elements and the γ'strengthening precipitate phase.It should be noted that recrystallization occurred during tensile testing at 500 ℃ with a few carbides observed in the vicin-ity of fracture surface,while the intergranular fracture phenomenon was attenuated.However,the fractography of specimens tested at 300 ℃ exhibit both intergranular and transgranular fracture without recrystallization.
GH4141 superalloyhigh temperature tensile propertydynamic strain agingdamagecarbides
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