Damage and Fracture in Creep of a Cast B1914 Superalloy

Abstract:

Damage and fracture processes in high temperature creep of an investment cast B1914 Ni-based superalloy with the increased amount of boron to 0.08wt.% for high temperature applications were analysed. Constant load creep tests in tension were conducted at temperatures from 800 to under applied stress ranging from 150 to 700 MPa. The microstructure of fractured specimens was investigated by scanning electron microscope Tescan equipped with an electron-back scatter diffraction. Microstructure investigation showed that the microstructure of the B1941 superalloy consists of a gamma (γ) phase with a dendritic structure and gamma prime (γ ́) phase with a cuboidal shape. Precipitates of γ ́and a lamellar eutectic, composed of γ/(Mo,Cr,Ni)₃B_2, were identified in the interdendritic region. Creep damage and fracture are closely connected with decohesion of the interface between M₃B₂ boride and matrix.

• Periodical: Key Engineering Materials (Volume 923)
• Pages: 87-92
• DOI: https://doi.org/10.4028/p-g50t0t
• Online since: June 2022
• Authors: Marie Kvapilová*, Petr Král, Jiří Dvořák, Karel Hrbáček, Květa Kuchařová, Václav Sklenička
• Keywords: B1941 Superalloy, Creep Damage, Creep Fracture, Investment Casting, Microstructure

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