Corrosion Behaviour of Borided and Nitrided Steels in Aqueous Media

Abstract

Case hardening may result in a considerable extension of the life of machine parts subjected to the simultaneous action of wear and aqueous corrosion, provided that the resistance of the hardened surfaces against corrosion attack is at least equal or superior to that of the base material. The present work is devoted to the effect of boriding and nitriding on the corrosion resistance of cast iron, mild steel and some stainless steels under different environmental conditions.

The results from electrochemical and conventional corrosion tests show that corrosion rates of nonalloyed iron-based materials, depending on the nature of the corrosive environment, are either decreased or not significantly influenced by boriding or nitriding. However, both nitriding and boriding may lead to a loss of corrosion resistance of stainless steels.