Effect of spinodal decomposition on the mechanical behavior of Fe–Cr alloys

Abstract The hardening behavior of precipitation was studied during aging of Fe–Cr alloys. This mechanical behavior is associated with the nanometric modulation structure of the coherent decomposed Fe-rich and Cr-rich phases formed by the spinodal decomposition of the supersaturated solid solution. The growth kinetics of spinodal decomposition was very slow and it increased during coarsening stage. The morphology of decomposed phases consisted of an interconnected irregular shape with no preferential alignment for short aging times and a further aging caused the change to a plate shape of the decomposed Cr-rich phase aligned in the 〈1 1 0〉 directions of the Fe-rich matrix. The rapid increase in hardness and embrittlement seem to be associated with the coherency and nanometer size of the spinodally decomposed phases in the aged alloys.

[1]  John W. Cahn,et al.  On spinodal decomposition in cubic crystals , 1962 .

[2]  J. E. Hilliard,et al.  Spinodal decomposition: A reprise , 1971 .

[3]  L. Schwartz,et al.  Further studies of spinodal decomposition in Fe-Cr , 1986 .

[4]  K. F. Russell,et al.  Effect of neutron-irradiation on the spinodal decomposition of Fe-32% Cr model alloy , 1996 .

[5]  Yoshiyuki Saito,et al.  Numerical simulation of phase separation in Fe-Cr binary and Fe-Cr-Mo ternary alloys with use of the Cahn-Hilliard equation , 2000 .

[6]  I. Lifshitz,et al.  The kinetics of precipitation from supersaturated solid solutions , 1961 .

[7]  C. M. Elliott,et al.  Spinodal decomposition in Fe-Cr alloys: Experimental study at the atomic level and comparison with computer models—I. Introduction and methodology , 1995 .

[8]  L. Schwartz,et al.  Mössbauer effect study of the 475‡C decomposition of Fe-Cr , 1971 .

[9]  W. Tiller,et al.  Computed low temperature phase equilibria in the system FeCr , 1972 .

[10]  Y. Ustinovshikov,et al.  Morphology of Fe–Cr alloys , 1998 .

[11]  Gernot Kostorz,et al.  Phase Transformations in Materials , 2001 .

[12]  P. Auger,et al.  Atom Probe Studies of the Fe–Cr System and Stainless Steels Aged at Intermediate Temperature: A Review , 2000 .

[13]  M. Miller,et al.  Spinodal decomposition of iron-32 at.% chromium at 470°C☆ , 1982 .

[14]  H. Mehrer.  Diffusion in Solid Metals and Alloys , 1990 .

[15]  Y. Ustinovshikov,et al.  Fe-rich portion of the Fe-Cr phase diagram: electron microscopy study , 2002 .

[16]  Y. Suwa,et al.  Kinetics of phase separation in iron-based ternary alloys. II. Numerical simulation of phase separation in Fe–Cr–X(X=Mo, Cu) ternary alloys , 2003 .