Concurrent phase separation and clustering in the ferrite phase during low temperature stress aging of duplex stainless steel weldments
Artikel i vetenskaplig tidskrift, 2012

The concurrent phase separation and clustering of alloying elements in the ferrite phase of duplex stainless steel weldments after stress aging at 325 degrees C have been investigated by atom probe tomography analysis. Both phase separation, into Fe-rich and Cr-rich ferrite, and solute clustering were observed. Phase separation in the heat-affected zone (HAZ) is most pronounced in the high alloyed SAF 2507, followed by SAF 2205 and SAF 2304. Moreover Cu clustering was observed in the HAZ of SAF 2507. However, decomposition in the weld bead (25.10.4L) was more pronounced than in the HAZs, with both phase separation and clustering of Ni-Mn-Si-Cu. The observed differences in the decomposition behaviors in the HAZ and weld bead can be attributed to the high Ni content and the characteristic microstructure of the weld bead with high internal strains. In addition, an applied tensile stress during aging of weldments has been found to further promote the kinetics of phase separation and clustering.

evolution

atom-probe

Atom probe tomography

alloys

Phase separation

Spinodal decomposition

electron-microscopy

ni

spinodal decomposition

Duplex stainless steels

fe-cr system

Författare

J. Zhou

Kungliga Tekniska Högskolan (KTH)

J. Odqvist

Sandvik

Kungliga Tekniska Högskolan (KTH)

Mattias Thuvander

Chalmers, Teknisk fysik, Materialens mikrostruktur

Chalmers, Teknisk fysik, Mikroskopi och mikroanalys

S. Hertzman

Outokumpu Stainless Research Foundation

Kungliga Tekniska Högskolan (KTH)

P. Hedstrom

Kungliga Tekniska Högskolan (KTH)

Acta Materialia

1359-6454 (ISSN)

Vol. 60 16 5818-5827

Ämneskategorier

Materialteknik

DOI

10.1016/j.actamat.2012.07.022