Influence of Electropulsing Treatments on Mechanical Properties of UNS S32750 Duplex Stainless Steel

Abstract

Prestrained at 5% and 15% duplex stainless steel UNS S32750 specimens have been subjected to electropulsing treatments with current density of 100 A/mm2 and 200 A/mm2 and 100 and 500 pulses for each current density value. Corrosion tests, X-ray diffraction, microhardness and residual stresses were collected before and after the electropulsing treatments. Tensile tests were performed after the electropulsing treatments in order to compare the mechanical response to reference tensile tests performed before pulsing treatments. Increase in fracture strain was observed after pulsing treatment in comparison to the reference tensile tests. A decrease in microhardness was also observed after electropulsing treatments for both degrees of prestrain. Electropulsing treatment almost eliminates the work-hardened state in the 5% prestrained specimens while partially recovered the 15% prestrained material increasing both uniform and fracture strain. Bulk temperature of the samples remained the same for all treatments duration. The effect are to be addressed to a combined effect of increase in atomic flux due to the electrical current and local joule heating in correspondence of crystal defects. Electropulsing treatment applied to metallic alloys is a promising technique to reduce the work hardening state without the need of annealing treatments in a dedicated furnace.

The AISI 317L and SAF 2304 Steels Pitting Corrosion Resistance in Acidified Glycerin from Biodiesel Production

“…Those phases are present in almost equal volume fraction. However, they can be embrittled, have their good corrosion properties affected, and the working temperature limited to 350 • C by a secondary phase precipitation, such as σ (sigma) or χ (chi) and other particles or phases such as Cr 2 N (chromium nitrides) or α' (alpha prime) 27,28 . Duplex stainless-steel passivation layer is stabilized by chromium and the nickel chemical content 29,30 .…”

Influence of Novel Electromagnetic Strengthening on Mechanical Properties of Spaceborne Elastic Components

“…(iii) The electromagnetic field can produce a field-induced plastic effect and improve the plasticity of the material. Some studies [33,[36][37][38][39] find that the field-induced plasticity effect generated by the interaction among the electromagnetic field, dislocations, residual stress, and grain boundaries can improve plasticity, reduce the processing resistance of metal materials, and improve formability.…”

Effect of Temperature on S32750 Duplex Steel Welded Joint Impact Toughness

“…Here, we consider S32750 duplex stainless steel (W. 1.4410) used for dynamically loaded components in the chemical and petrochemical industries, as well as in aeronautical engineering more recently. It is often used in aggressive corrosion environments with service temperature limits below 350 °C [ 13 ]. Duplex alloy is a descriptor of an alloy where two phases are present in significant quantities, as in the case of basic duplex stainless steel made of a ferritic/austenitic Fe-Cr-Ni alloy with 30–70% ferrite.…”

“…During the 1980s, more highly alloyed duplex grades were developed to withstand more aggressive environments. The so-called superduplex grades contain about 25% Cr, 6–7% Ni, 3–4% Mo, 0.2–0.3% N, 0–2% Cu, and 0–2% W, as in the case of S32750 stainless steel designed for highly corrosive environments [ 13 ].…”