Nanostructure, Mechanical Properties, and Corrosion Resistance of Super Duplex Stainless Steel 2507 Aged at 500 °C

Abstract

In order to investigate the effect of phase separation (PS) on the super duplex stainless steel SAF 2507, the evolution of the nanostructure, mechanical properties, and corrosion resistance of the alloy was studied after aging at 500 °C for 1, 10, 100, and 1000 h. The nanostructure of PS was quantitatively characterized by small-angle neutron scattering. The hardness, impact toughness, and pitting corrosion resistance were measured for different conditions. The results show that the early stage of PS had a more significant impact on the nanostructure and properties of SAF 2507. The fracture behavior of the alloy was likely determined by the mechanical properties of ferrite for aged conditions. The pitting corrosion resistance of SAF 2507 aged at 500 °C was closely related to the Cr depletion caused by PS, and the resistance became weaker with the progression of PS. The evolution of the passivation region with aging time correlated well with that of mechanical properties and characteristic parameters of PS, indicating that it is possible to develop a new nondestructive electrochemical method to quantify the evolution of PS in SAF 2507.

Fabrication of Mechanically Alloyed Super Duplex Stainless Steel Powder-Modified Carbon Paste Electrode for the Determination of Methylene Blue by the Cyclic Voltammetry Technique

“…Notably, super duplex stainless steel contains less nickel (Ni) than standard austenitic grades while maintaining excellent strength and remarkable malleability. These steels are the material of choice for applications demanding outstanding performance in harsh and corrosive conditions due to their unique combination of characteristics. , An additional advantage of super duplex stainless steel is its lower Ni concentration, making it suitable for use as a biomaterial in situations where patients might experience hypersensitivity due to higher Ni content. Super duplex stainless steels find application in orthopedic devices such as Harrington rods for scoliosis treatment, addressing abnormal lateral curvature of the spine thanks to their increased biocompatibility.…”

“…Mechanical alloying involves the use of high impact force, leading to phase transition, microstructure refinement, repetitive cold welding, severe plastic deformation, and powder particle fracture. Finer microstructures achieved through mechanical alloying offer unique qualities such as increased surface area, oxidation resistance, and strength. − Mechanically alloyed super duplex stainless steels find applications in various electrochemical sensing applications, including the detection of heavy metals in environmental pollutants, monitoring of chemical and biological parameters, identification of hazardous substances in food, and the diagnosis of bacteria and viruses, among others. − In this study, SAF-2507 super duplex stainless steel nanoparticles were ball-milled for 20 h to produce a modified carbon paste electrode (DSS-MCPE) for the detection of methylene blue in wastewater. The research conducted on creating super duplex stainless steels by mechanical alloying is outlined in Table .…”

Optimization of plasma arc welding process parameters of SAF 2507/316L dissimilar steel based on response surface method

“…On the other hand, SAF 2507 has good performance in all aspects, but it is more expensive to completely replace 316L to make pipes, so replacing SAF 2507 with SAF 2507 in some key parts can reduce the cost. Due to the dual-phase nature of SAF 2507 (50% austenite and 50% ferrite), the presence of austenite phase improves toughness, while the presence of ferrite phase improves yield strength and reduces stress corrosion cracking or hot cracking, so SAF 2507 performs excellent in strength, toughness and corrosion resistance [2][3][4][5].…”