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Title: Effect of Boron Addition on Creep Strain during Impression Creep of P91 Steel

Journal Article · · Journal of Materials Engineering and Performance
 [1];  [2];  [1]
  1. Dr. B R Ambedkar National Institute of Technology, Department of Mechanical Engineering (India)
  2. CSIR-National Metallurgical Laboratory, Project Planning and Engineering Division (India)

In an attempt to understand the effect of boron addition on creep deformation behavior under high stress and high temperature in martensitic P91 steel, impression creep tests were carried out on boron-free P91 (P91) and boron-added P91 (P91B) steels. The experimental program consisted of three steps, i.e., characterization of as-received steels by microhardness, optical microscopy (OM), transmission electron microscopy (TEM), electron backscattered diffraction (EBSD) and wavelength-dispersive spectroscopy (WDS); impression creep tests at 445 MPa and 625 °C on as-received steels; characterization at deformed plastic zones of impression-crept specimens by microhardness, OM, EBSD, TEM and WDS. Impression creep tests were run till a depth of penetration of 1.8 mm was achieved for both cases which ensured a sufficient plastic zone underneath indenter for subsequent microstructural investigations. Coarsening of M{sub 23}C{sub 6} carbides was observed in P91 steel during high-temperature creep loading, which leads to extensive strain hardening in deformed plastic region, resulting in impaired creep performance. On the contrary, dynamic recrystallization in P91B steel results in formation of small strain-free grains during creep loading which are responsible for increased resistance of the material to shear stresses during an impression creep test.

OSTI ID:
22970660
Journal Information:
Journal of Materials Engineering and Performance, Vol. 28, Issue 7; Conference: 73. World Foundry Congress, Krakow (Poland), 23-27 Sep 2018; Other Information: Copyright (c) 2019 ASM International; Country of input: International Atomic Energy Agency (IAEA); ISSN 1059-9495
Country of Publication:
United States
Language:
English