Fatigue and corrosion-fatigue behavior of 13Cr-4Ni steels and additively manufactured alloys, for application to large size components such as hydraulic turbines and machineries

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According to a study on hydroelectricity in Quebec: "35,125 MW (out of 35,829 MW) of Quebec's installed capacity is hydroelectric. There are 25 large hydro reservoirs within Québec, which can store water on a multi-annual basis and help manage electricity deliveries to internal and export markets. Due to the availability of inexpensive electricity and electric promotion activities, 76% of households in Quebec use an electric heating system. Quebec has an extensive high-voltage transmission system, transporting electricity over long distances from mostly northern hydro dams towards southern demand centers". Hydro-Québec's production fleet, comprises more than 350 hydraulic turbines. Viewing the complexity of their geometry, these runners are assembled by welding resulting in heterogeneous and complex microstructures. In service, hydraulic turbines are subjected to cyclic loads, cavitation and corrosion. Water corrosiveness can increase damages and reduce operating life as a result of the combined effects of mechanical fatigue and corrosion. In this multidisciplinary project we propose to evaluate the synergistic effects of fatigue and corrosion to further understand the degradation mechanism of the alloys used by our two partners. This will help the partners defining their total cost of ownership & develop mitigating corrosion strategies to ensure long term sustainability of their infrastructure. Specifically, we will i) study two types of iron based alloys (stainless steel and cast iron), ii) quantify their corrosion properties, iii) study their fatigue properties and iv) develop predictive fatigue-corrosion models that will aid our partners in their technology development.