MECHANICAL-BEHAVIOR AT HIGH-TEMPERATURE OF A CENTRIFUGALLY-CAST STAINLESS-STEEL TUBE

Mechanical properties at high temperature of a centrifugally-cast stai nless steel tube have been investigated by torsion tests. Microstructu re and composition have been determined in different positions along t he tube radius. Differences in the microstructure related to different solidification rates have been observed between the interior and exte rior zones. Garofalo's equation has been calculated considering the re sults of torsion tests of samples obtained from both zones. A similar value for the activation energy and hyperbolic sinus exponent have bee n observed in both cases. However, a change in ductility and fracture stress between both zones has been found at temperatures above 1100 de grees C.