Investigation of the Effect of Hydrogen Penetration on Microstructure and Corrosion Behavior of UNS S۳۲۷۵۰ Super Duplex Stainless Steel and its Welded Joint in ۳.۵% NaCl in Hydrogen Transfer Tubes

In this study the effect of hydrogen penetration on the UNS S۳۲۷۵۰ super duplex stainless steel WAS investigated. As the main purpose, the effect of welded section in ۳.۵% sodium chloride solution on the microstructure, corrosion behavior, as well as initiation and propagation of pits WAS investigated in this paper. In order to investigate hydrogen penetration, the samples were cathodically charged at a potential of -۱۳۰۰ mV (SCE) for ۱۶۰h at room temperature. Furthermore, to analyze the effect of hydrogen penetration on the initiation and expansion of the pits, the samples were stored for a period of ۱۶۰h before and after cathodic charging at a constant potential of ۸۰۰ mV (SCE). Scanning electron microscopy images are also available from Fracture surfaces. The results of the tensile test show that hydrogen penetration on the UNS S۳۲۷۵۰ super duplex stainless steel reduces the strain from ۶۴.۱ to ۵۸.۲% for simple sample, and ۴۶.۹ to ۳۸.۴% for welded samples. In addition, the results of Potentiodynamic and Potentiostatic tests indicated that hydrogen penetration increased the corrosion rate and increased the number and propagation of the pits

Keywords:

Super duplex stainless steel , Hydrogen penetration , Mechanical properties , Microstructure , Corrosion behavior , فولاد زنگ نزن سوپر دوفازی , نفوذ هیدروژن , خواص مکانیکی , ریزساختار , رفتار خوردگی