Rust Is Not a Must. Improvement of Discs Corrosion Resistance by Tuning of Grey Cast Iron Alloying Elements and Microstructure (SAE Paper 2020-01-1624)

The manuscript reports about the corrosion performance of a series of grey cast iron specimens including an increasing concentration of Aluminum as alloying element. An improved corrosion resistance for %Al >1%wt is demonstrated and a reasonable corrosion mechanism is proposed as well. Electrochemical techniques allow to calculate a particularly high corrosion potential (Ecorr) for the sample including 4%wt Al, equals to -572 mV vs. Saturated Calomel Electrode (SCE). The manuscript is aimed at demonstrating that the fine tuning of alloying elements in cast iron is a particularly effective method in order to improve its corrosion resistance, thus allowing the development of future disc-brake rotors with a prolonged operating life.