Synthesis of Nitrogen Alloyed Steels by Arc Melting Technique for Improved Properties

Abstract

Incorporation of nitrogen into 30CrMnSiA and 316 Stainless Steel was executed by arc melting furnace at 3500ºC by altering the nitrogen pressure from 0.1bar to 0.3bar. Characterization techniques involved the optical microscopy (OM) for investigation of microstructure, X-ray diffraction and SEM (Scanning Electron Microscopy) with EDX (Energy Dispersive X-ray Spectroscopy).It was suggested that nitrogen incorporation into 30CrMnSiA and 316 stainless Steel was a favorable way to attain high hardness.Nitrogen comprising steel samples exhibited superior corrosion resistance as compared to the raw steel specimens when they are examined in electrolyte solution of 3.5wt% NaCl. Tafel plots and polarization resistance results revealed that the corrosion resistance from argon melted steel sample to high nitrogen incorporated samplewas improved from 14.13mpy to 6.70mpy, 0.06606mpy to 0.02677mpy and from 12.28 to 4.81, 0.02mpy to 0.010mpy for 30CrMnSiA and for 316ss respectively. These results suggest that nitrogen is beneficial for anticorrosion properties in different media. By linking the benefits of nitrogen added 30CrMnSiA and for 316SS, low density, high hardness and more corrosion resistant steel as compared to presently used raw steel ,the recently developed nitrogen incorporated steel is a trustworthy substitute for marine application.