The 475 degrees C embrittlement in Fe-20Cr and Fe-20Cr-X (X=Ni, Cu, Mn) alloys studied by mechanical testing and atom probe tomography
Journal article, 2013

In the present work the 475 degrees C embrittlement in binary Fe-Cr and ternary Fe-Cr-X (X=Ni, Cu and Mn) alloys have been investigated. The mechanical properties were evaluated using microhardness and impact testing, and the structural evolution was evaluated using atom probe tomography (APT). The APT results after aging at 500 degrees C for 10 h clearly showed that both Ni and Mn accelerate the ferrite decomposition. No evident phase separation of either the Fe-20Cr or Fe-20Cr-1.5Cu samples was detected after 10 h of aging and thus no conclusions on the effect of Cu can be drawn. Cu clustering was however found in the Fe-20Cr-1.5Cu sample after 10 h aging at 500 degrees C. The mechanical property evolution was consistent with the structural evolution found from APT. Samples aged at 450 and 500 degrees C all showed increasing hardness and decreasing impact energy. The embrittlement was observed to take place mainly during the first 10 h of aging and it could primarily be attributed to phase separation, but also substitutional solute clustering and possibly carbon and nitrogen segregation may contribute in a negative way.

Atom probe tomography

Spinodal decomposition

Mechanical properties

475 degrees C embrittlement

Phase separation

Ferritic stainless steels

Author

P. Hedstrom

Royal Institute of Technology (KTH)

H. Y. Fei

Royal Institute of Technology (KTH)

J. Zhou

Royal Institute of Technology (KTH)

S. Wessman

Swerea KIMAB

Mattias Thuvander

Chalmers, Applied Physics, Materials Microstructure

J. Odqvist

Royal Institute of Technology (KTH)

Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

0921-5093 (ISSN)

Vol. 574 123-129

Subject Categories

Nano Technology

Metallurgy and Metallic Materials

DOI

10.1016/j.msea.2013.03.016

More information

Latest update

2/28/2018