Corrosion Resistance and Cytotoxicity Study of 17-4PH Steels Produced by Conventional Metallurgy and Powder Injection Molding

Abstract

The corrosion resistance of 17-4PH stainless steel obtained by powder injection molding (PIM) was investigated in a phosphate buffer solution (PBS) that simulates physiological solution and compared with that of 17-4PH steel obtained by conventional metallurgy. The corrosion resistance was investigated by electrochemical techniques for different immersion times. The cytotoxicity of both types of 17-4PH steel was also investigated using a minimum Eagle’s medium (MEM). The MEM solution is a type of cell culture medium, which simulates physiological fluids. The cytotoxicity assay was carried out by neutral red uptake methodology utilizing NCTC L929 cell line from ATCC bank and none of the steels showed cytotoxic effects. The resulting extracts obtained by immersion of the steel samples in MEM were analyzed by neutron activation analysis and the results indicated liberation of chromium and cobalt as corrosion products but in very low amounts. The electrochemical evaluation of both steels indicated that they are passive in PBS but presented susceptibility to pitting. The 17-4PH PIM steel was slightly more susceptible to pitting than that fabricated by conventional metallurgy due to its inherent porosity.