Surface alloying on austenitic stainless steel with titanium and tungsten using gas tungsten arc

Abstract

An evaluation was carried out on AISI304 stainless steel by adding tungsten and titanium on the surface using gas tungsten arc as heat source under argon and nitrogen atmosphere were performed. The microstructure was observed be refined. The SEM image shows the dispersion of tungsten particles in the alloyed layer. The EDS analysis confirms presence of Cr, Ni, N, W, Fe and Ti on the alloyed layer. The XRD reports the presence of intermetallic phases in the alloyed layer. The hardness of the alloyed layer was increased from 277HV to 1968HV for W and Ti alloyed layer under argon atmosphere and 2139HV for W and Ti alloyed layer under Nitrogen atmosphere, with decreasing the wear rate from 1.09 × 10−4 mm3 m−1 to 7.08 × 10−6 mm3 m−1 and further decreased to 4.58 × 10−6 mm3 m−1 for W and Ti alloyed layer under argon and nitrogen atmosphere, respectively. Corrosion resistance of the surface alloyed layer was studied in a HANKS balance salt solution with a pH range of ∼7.2 ± 0.2 by Tafel polarization. The alloyed layers exhibits an effective improvement towards the corrosion than the substrate.