Monel400

1. Introduction to Monel400 Materials

Monel 400 is a widely used corrosion-resistant alloy with outstanding comprehensive performance. It exhibits excellent corrosion resistance in hydrofluoric acid and fluorine gas, as well as hot concentrated alkaline solutions. This nickel-based alloy performs well in seawater, neutral solutions, chemical solvents, ammonium chloride, hydrogen chloride, various acids (sulfuric acid, hydrofluoric acid, hydrochloric acid, phosphoric acid, organic acids), alkaline media, salts and molten salts.

A key advantage of this alloy is that it rarely suffers stress corrosion cracking, and it boasts good machinability. Monel400 features a high-strength single-phase solid solution metallographic structure.

2. Monel400 Chemical Composition

3. Physical performance of Monel400

Minimum room-temperature mechanical properties of the alloy:

Monel400 Mechanical Properties

4. Monel400 Material characteristics

Monel400 is a widely used corrosion-resistant alloy with excellent comprehensive performance. It resists hydrofluoric acid, fluorine gas and hot concentrated alkaline liquids, as well as neutral solutions, water, seawater and organic compounds. A prominent feature is resistance to stress corrosion cracking, paired with good machinability.

The metallographic structure of Monel400 is a high-strength single-phase solid solution.

5. Monel400 corrosion resistance:

• Monel 400 alloy shows superior corrosion resistance against fluorine gas, hydrochloric acid, sulfuric acid, hydrofluoric acid and their derivatives; it outperforms copper alloys in seawater service.
• Acid medium: Resistant to sulfuric acid below 85% concentration, and it is one of the few key materials resistant to hydrofluoric acid.
• Water corrosion: Excellent anti-corrosion performance under most aqueous environments, minimal pitting and stress corrosion, corrosion rate below 0.25mm/a.
• High temperature corrosion: Continuous service temperature in air up to roughly 600℃; corrosion rate less than 0.26mm/a in high-temperature steam.
• Ammonia: High nickel content enables resistance to anhydrous ammonia and ammoniation environments below 585°C.

6. Monel400 application fields

• Power plant seamless water pipes and steam pipes
• Seawater heat exchangers and evaporators
• Equipment for sulfuric acid and hydrochloric acid service environments
• Crude oil distillation equipment
• Pump shafts and spiral impellers for deep seawater facilities
• Nuclear industry equipment for uranium refining and isotope separation
• Pumps and valves for hydrochloric acid production equipment