Pages 197-198
Precipitated hardening advanced heat resistant materials such as Ni-base super alloys have been developed so that a creep crack grows in a branched manner due to the strengthening effect of the second phase of material structure. In this paper, using IN100 alloys with γ' strengthening structure, in-situ observational creep tests were conducted to observe branched crack growth behaviors. On the basis of this phenomenon, a mechanical model of a branched crack was constructed and FEM analysis on the creep crack growth was conducted by the method of releasing nodal points. This result showed the mechanical effect of a branched crack on the creep crack growth curve.
