Microstructural characterisation and microanalysis of creep resistant steels

Electron Microscopy and Analysis Group Conference 2013

Wang, M.^1 ; Chiu, Y.^1 ; Jones, I.^1 ; Rowlands, N.^2 ; Holland, J.^2 ; Zhang, Z.^3 ; Flahaut, D.^4

School of Metallurgy and Materials, University of Birmingham, B15 2TT Birmingham, United Kingdom^1

Oxford Instruments NanoAnalysis, Halifax Road, HP12 3SE High Wycombe, United Kingdom^2

Doncasters Technical Centre, George Baylis Road, Worcestershire, WR9 9RB, United Kingdom^3

Doncasters Paralloy Ltd, Paralloy House, Nuffield Road, Cleveland-TS23 4DA, United Kingdom^4

关键词: Chromium carbide;    Creep resistant steels;    Microstructural characterisation;    Niobium carbide;    Primary carbides;    Scanning transmission electron microscopy;    Secondary carbides;    Secondary precipitates;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/522/1/012034/pdf
DOI  :  10.1088/1742-6596/522/1/012034

来源: IOP

【 摘 要 】

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, M7C3and M23C6was confirmed by electron diffraction. The primary chromium carbides transformed from M7C3to M23C6during 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 mm2windowless X-MaxNSDD at 3 kV on an SEM. Scanning transmission electron microscopy (STEM) observations showed the appearance of fine NbC, G phase (Ni16Nb6Si7) and (Nb, Ti)(C, N) particles.