Following the findings from previous research studies which concerns the influence of welding techniques on the corrosion behaviour of the fused materials, a dedicated project on the optimization of friction stir welding parameters towards beneficial corrosion behaviour of high-strength lightweight alloys EN AW-7075 and EN AW-7020 was initiated in 2020. As this welding technique allows fusion below the melting point by increased plastification, the heat transfer into the adjacent material is significantly lower compared to e.g. laser beam welding. Several approaches towards lowering the corrosion susceptibility of the heat affected zone that usually increases through grain growth and intermetallic phase precipitation are part of the working plan. Special interest is given to increased plastification by the use of innovative multi-pin welding tools that eventually allows for even cooler fusion temperatures, which means less heat input and thus reduced corrosion susceptibility of the heat affected zone. The corrosion behaviour is tested by means of full material immersion and electrochemical measurement that allows the investigation of the corrosion kinetics. Using metallographic cross-sections before and after the tests, the microstructural mechanisms that influence the initiation of corrosion can be identified. While EN AW-7075 joints offers higher strength, the corrosion of the weld seam is lower for EN AW-7020. However, EN AW-7020 heat affected zones suffer from exfoliation corrosion. By reflecting on the varied parameters during the welding supported by temperature measurements, recommendations on the welding parameters to achieve ideal corrosion behaviour can be deduced.