2017 Volume 58 Issue 10 Pages 1379-1385
The effect of austenite (γ) phase stability in the local deformation region on the deformation energy of ferrite (α)-γ duplex stainless steel is investigated using tensile testing. The uniform deformation energy values of both the γ-stable and unstable duplex stainless steels are similar, while the local deformation energy of γ-stable duplex stainless steel is larger than that of γ-unstable duplex stainless steel. In γ-unstable duplex stainless steel, the difference in nano-indentation hardness between the α and transformed martensite (α') phases increases remarkably beneath the fractured surface. Low-voltage electron microscopy observations reveal that voids grow rapidly at the grain boundaries between the α and α' phases beneath the fractured surface, resulting in a decrease in the local deformation energy in γ-unstable duplex stainless steel.
This Paper was Originally Published in Japanese in J. Jpn. Soc. Heat Treatment 56 (2016) 285–291.
