Abstract

MEDINA, Nakary; RODRIGUEZ, Edda  and  STELLA, Jorge. Microstructural characterization of the sigma phase precipitation and disolution in the saf 2507 steel. Rev. Fac. Ing. UCV [online]. 2011, vol.26, n.4, pp.45-53. ISSN 0798-4065.

This study shows the characterization of a superduplex stainless steel SAF 2507 after aging treatments at 875 and 970 °C. The first treatment promotes the precipitation of the sigma phase and the second one, its dissolution. The microstructural evaluation of both treatments was carried out by optical and scanning electron microscopy.The results showed an increase of the sigma phase fraction with the time of aging treatment at 875 °C, and an almost complete transformation of the ferrite phase in sigma and secondary austenite. On the other hand, increasing the time of treatment at 970 °C promotes a reduction of the sigma phase and the corresponding increase of the ferrite phase fraction. Furthermore, the study also showed the effect of sigma phase precipitation on the hardness.

Keywords : Superduplex stainless steel; Aging treatment; Dissolution; Sigma phase; Secondary austenite.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )