Precipitation kinetics during aging of an alumina-forming austenitic stainless steel

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:667

Article

Trotter, Geneva¹  Hu, Bin¹  Sun, Annie Y.¹  Harder, Reed¹  Miller, M. K.²  Yao, Lan²  Baker, Ian¹ 

[1] Dartmouth Coll, Thayer Sch Engn, Hanover, NH 03755 USA

[2] Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Oak Ridge, TN 37831 USA

关键词: Austenite;    Intermetallics;    Aging;    Coarsening;    Grain boundaries;    Precipitation;   

DOI  :  10.1016/j.msea.2016.04.081

来源: Elsevier

【 摘 要 】

The microstructural evolution of DAFA26, an alumina-forming. austenitic (AFA) stainless steel, was investigated during aging. The effect of aging at 750 degrees C and 800 degrees C on the growth of spherical gamma'-Ni-3(Al, Ti) particles present in the as-processed state was studied extensively using X-ray diffraction, microhardness testing, scanning electron microscopy, transmission electron microscopy, and atom probe tomography. The le particles had a cube-on-cube orientation relationship with the matrix (i.e. ((010)(m)//(010)(p), [100](m)//[100](p))). The coarsening kinetics of gamma'-Ni3Al particles were in agreement with the Lifshitz, Slyozof-Wagner theory. Coarse Laves phase particles were also present in the as-processed state, and during the aging process both smaller Laves phase precipitates and B2-NiAl precipitates formed on both the grain boundaries and in the matrix. The gamma' precipitates were determined to have the most impact on the room temperature hardness. (C) 2016 Elsevier B.V. All rights reserved.

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