Forged and nitrided 316L stainless steel to mitigate corrosion in heat exchangers for water purification processes.

Maintaining corrosion-free equipment in water purification processes is vital, as these processes aim to produce fresh water. Corrosion is a degradation process that affects metals, and heat exchangers are constructed from metals or alloys. This project analyzes and mitigates corrosion in 316L stainless steel heat exchangers that use lithium bromide (LiBr) as an absorber. These units are used in heat pumps for water purification. The effects of forging and nitriding processes will be studied on test specimens to evaluate their corrosion resistance, mechanical properties, and improved longevity. Subsequently, these processes will be applied to a full-scale heat exchanger. Twenty samples will be taken: five will be nitrided, five will be forged, and five will be both forged and nitrided. Both as-received and forged, nitrided, and nitrided-forged samples will be characterized for their mechanical behavior (wear, hardness, and tensile strength tests) and corrosion resistance using electrochemical techniques such as potentiodynamic polarization, electrochemical impedance, and electrochemical noise in a LiBr/H₂O electrolyte. The expected results are an austenitic steel with high resistance to pitting corrosion, ideal for the heat exchanger industry, as developing materials to mitigate corrosion in this equipment remains a challenge. A scale-model heat exchanger will also be developed to assess its functionality over time.