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
Artikel i vetenskaplig tidskrift, 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


P. Hedstrom

Kungliga Tekniska Högskolan (KTH)

H. Y. Fei

Kungliga Tekniska Högskolan (KTH)

J. Zhou

Kungliga Tekniska Högskolan (KTH)

S. Wessman

Swerea KIMAB

Mattias Thuvander

Chalmers, Teknisk fysik, Materialens mikrostruktur

J. Odqvist

Kungliga Tekniska Högskolan (KTH)

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

0921-5093 (ISSN)

Vol. 574 123-129



Metallurgi och metalliska material