Microstructure and Corrosion Response of Spark-Plasma-Sintered 304 Austenitic Stainless Steel Reinforced with Titanium Nitride in Chloride Environments

The replacement of carbon steel by stainless steel in industries where excellent corrosion resistance is required is currently gaining momentum. The susceptibility of titanium nitride (TiN)-reinforced austenitic stainless steel fabricated using sintering technique was investigated in ferric chloride (FeCl₃) and 3.5 wt.% NaCl. Microstructural observation of the sintered specimens from scanning electron microscope showed even dispersions of titanium nitride (TiN) in the matrix of austenitic stainless steel, which further confirmed the effectiveness of turbula mixing technique. Pitting corrosion resistance of specimens reinforced with 2 and 4 wt.% TiN was observed to show an improvement in ferric chloride solution after an immersion period of 96 h. The phases formed on the surface of the specimen after electrochemical test is presented in the X-ray diffraction analysis. The pitting corrosion of the sintered austenitic stainless steel specimens was also improved upon the addition of titanium nitride nanoparticles as confirmed from cyclic potentiodynamic polarization test results.