Nickel alloys are known for their corrosion resistance, but each material has its own special focus. This newsletter gives a quick summary of the t
op grades.
 Monel: Saltwater…And StrengthFor years, Monel bolts have been the go-to material for saltwater resistance by the military. It offers excellent strength and toughness for naval applications with Grade K500 offering 2x’s the strength (160ksi) of grade 400 (80 ksi). Monel bolts even perform well in rapid seawater which can erode other materials.In addition to saltwater conditions, Monel 400 is also one of the few materials that can handle hydrofluoric acid. In HF, Monel bolts perform well in all concentrations up to the boiling point.
Hastelloy: Extreme Corrosion Grade C276 is the most common grade offering the broadest resistance to acids, chemicals, solvents and chlorides. Hastelloy B2 and B3 focus more directly on HCl, offering excellent resistance in most temperatures and concentrations.
Inconel 625 not only offers the high temperature oxidation resistance (to 1800°F), but it is also useful in seawater, acids and other chemicals. Compared to Hastelloy it offers slightly less corrosion resistance, but higher strength. Inconel 625 is typically used for environments where high strength is necessary. For even higher strength corrosive environments, Inconel 718 bolts are ideal. 718 is an age hardened version of Inconel 625 and can offer tensile strength up to 220ksi, as well as excellent corrosion resistance to some of the harshest acids. |
