Hastelloy and Inconel, Monel each have their own characteristics in terms of corrosion resistance, strength and high temperature performance.
Hastelloy alloy
Features: Hastelloy bolts are one of the most widely used materials for high temperature corrosive environments, able to withstand chemicals such as hydrochloric acid and sulfuric acid, even at high temperatures and high concentrations.
Application: Hastelloy is usually only after pure tantalum, but the price is higher. Hastelloy C276 is the most common grade, providing the widest range of acids, chemicals, solvents and chlorides corrosion resistance. Hastelloy B2 and B3 are more focused on HCl, providing excellent corrosion resistance at most temperatures and concentrations.
Inconel alloy
Features: Inconel is often used for high temperature strength, but also plays a role in corrosive applications. Inconel 600 and 601 are very suitable for hot corrosion and oxidation resistance.
Application: Inconel 625 not only provides high temperature oxidation resistance (up to 1800°F), but is also suitable for seawater, acids and other chemicals. Compared with Hastelloy, it provides slightly lower corrosion resistance, but higher strength. Inconel 718 is suitable for higher intensity corrosive environments and is an age-hardened version of Inconel 625, which can provide tensile strength up to 220ksi and excellent corrosion resistance to some of the harshest acids.
Monel Alloy
Features: Monel alloys are well known for their corrosion resistance in salt water, especially the K500 grade commonly used by the military, which is twice as strong as the 400 grade (160ksi vs. 80 ksi).
Applications: In addition to salt water environments, Monel 400 can handle hydrofluoric acid and works well in all concentrations up to boiling point.
