Cyclic deformation behavior on lean duplex stainless steels

R STRUBBIA; S HEREÑU; I ALVAREZ

Beaune

Conferencia; 8th Duplex Stainless SteelsnConference; 2010

A significant amount of research has been devoted to the development of new duplex stainless steels (DSS) containing low Ni, also called Lean DSS (LDSS). Though in recent years a number of researchers have studied the structural characterization and corrosion properties of LDSS, no information is available on their fatigue behavior. Therefore, the purpose of this investigation is to analyze the cyclic behavior at room temperature of LDSS AL 2003 (UNS S32003) and LDX 2101 (UNS S3210) at different total strain ranges. The fatigue dislocation structure was analyzed by a transmission electron microscopy (TEM). Within the studied strain ranges, in both LDSS the cyclic behaviour seems to be controlled by the ferrite phase and is characterized by an initial cyclic hardening followed by cyclic softening. Nevertheless, LDX 2101 shows a higher fatigue life and cyclic softening rate than AL 2003. Moreover, for all the employed strain ranges LDSS AL 2003 attains higher stress level than LDX 2101 which could be attributed to the higher molybdenum content in the AL 2003. For each applied strain range, the dislocation structure in the ferritic phase of LDX 2101 shows a premature evolution in relation to that observed in AL 2003.