The mechanical properties and seawater behavior of Nitronic 50 (22Cr- 13Ni-5Mn) have been investigated. One-inch base plate and gas metal-arc weldments were used for this study. Good elongation and toughness properties were obtained. The yield strength of the weld metal was overmatching (80 versus 63 thousand pounds per square inch). The alloy demonstrated satisfactory stress- corrosion resistance. Base metal, high- and low-cycle fatigue performance was excellent, but gas metal-arc weldments performed poorly because of weld porosity. The corrosion behavior of Nitronic 50 is not adversely affected when coupled to common naval alloys. In most cases, it behaves cathodically and accelerates the corrosion of these alloys. While Nitronic 50 does not display general pitting corrosion, it does evidence crevice corrosion, but to a much lesser degree than most common stainless steels.