Differentiating Nickel Alloys: Monel, Hastelloy & Inconel?

Nickel alloys are known for their corrosion resistance, but each material has its own special focus. This newsletter gives a quick summary of the top grades.

 

 

 

 

 

 

Monel: Saltwater…And Strength
For 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
Hastelloy bolts are one of the most widely used materials for high temperature corrosion. It can handle chemicals like hydrochloric and sulfuric acids – even at high temperatures and concentrations (insert charts). Hastelloy is typically only surpassed by pure tantalum – though at a high price tag. Hastelloy bolts are also commonly used in oil fields for H2S (sour gas corrosion), chemical plants and flue gas desulfurization.

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: Combo of Strength, Heat, AND Corrosion
Inconel bolts are most often used for high temperature strength but they also play a role in corrosive applications. Inconel 600 and 601 are excellent for hot corrosion and oxidation resistance.

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.

This entry was posted in Application, Blog, Corrosion Resistance, High Strength, High Temperature Resistance, Material, Specialty Metal Fasteners and tagged , , , , , . Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *

Fragen?

Unsere Materialexperten stehen bereit, Sie bei Ihrer spezifischen Anwendung zu unterstützen.

Kontaktieren Sie einen Experten