ESSC & DUPLEX 2019

It is well known that increasing the temperature soften the materials and increase its formability. This could be done in many ways, one of which is by joule heating. In the late fifties, an enhancement of formability for certain alloys, when heated by electrical current compared to traditional heating method, has been observed . This led the researcher to investigate the effect of electrical current on the plastic flow of metallic materials discovering a new effect called Electroplastic Effect (EPE). EPE is used in the so called Electrically Assisted Manufacturing processes (EAM). The stacking fault energy (SFE) describes the dislocation dynamics of metallic materials and it has been hypothesized an a-thermal effect which is caused by direct interaction between dislocations and electrical current. High SFE materials shows an increase of formability while low SFE materials reach the fracture prematurely. In this work duplex stainless steel (DSS) UNS S32507 has undergone uniaxially tested with the aid of continuous and pulsed electrical current in order to study the EPE of an alloy with s two phases: high SFE (ferrite) and low SFE (austenite). It has been tested under different current densities (continuous and pulsed). In order to separate the EPE from the effect of temperature, some thermal tensile counterpart tests have been conducted. The DSS was then characterized through optical microscopy, scanning electron microscopy and x-ray diffraction. The DSS shows an increase in the elongation at rupture either for the continuous current set-up and much more evident in the case of the pulsed current , compared to the thermal tests while the ultimate tensile strength and the yield strength were barely affected.