Microstructural characterisation and microanalysis of creep resistant steels

M. Wang (1) , Y. Chiu , I. Jones , N. Rowlands , J. Holland , Zhongkai Zhang , Delphine Flahaut (1)

1 School of Metallurgy and Materials

Steels for high temperature applications require good creep resistance which is controlled by the chemistry and microstructure of the materials. This paper focuses on the microstructural characterisation of a creep resistant steel using electron microscopy. The existence of various primary carbides, e.g. NbC, M7C3 and M23C6 was confirmed by electron diffraction. The primary chromium carbides transformed from M7C3 to M23C6 during creep while the niobium carbides were nearly unaltered. In addition, secondary precipitates (M23C6) were observed within the matrix after creep. The size and distribution of the secondary carbides were analysed by a 80 mm2 windowless X-Max N SDD at 3 kV on an SEM. Scanning transmission electron microscopy (STEM) observations showed the appearance of fine NbC, G phase (Ni16Nb 6Si7) and (Nb, Ti)(C, N) particles. © Published under licence by IOP Publishing Ltd.

Domaines: Chimie; Matériaux

M. Wang, Y. Chiu, I. Jones, N. Rowlands, J. Holland, et al.. Microstructural characterisation and microanalysis of creep resistant steels. Journal of Physics: Conference Series, 2014, 522 (1), ⟨10.1088/1742-6596/522/1/012034⟩. ⟨hal-01499428⟩