Monel 400

MONEL 400 (UNS N04400) is a nickel-copper alloy renowned for its outstanding corrosion resistance, especially in marine and chemical environments. This alloy maintains excellent mechanical properties across a wide temperature range (from cryogenic temperatures to approximately 482 °C / 900°F) and is widely used in marine engineering, chemical processing, and oil and gas industries.​.

Behaviour that matters in service

• Superior Corrosion Resistance — MONEL 400 exhibits exceptional resistance to corrosion in seawater, brine, and various chemical solutions (such as sulfuric acid, hydrochloric acid, and alkaline solutions). It is highly resistant to pitting, crevice corrosion, and stress corrosion cracking, making it ideal for marine and chemical applications.​.
• Excellent Mechanical Properties — The alloy maintains high tensile strength, yield strength, and ductility at both low and moderate temperatures. Even in cryogenic environments, it retains good toughness without becoming brittle.​.
• Good Fabricability — MONEL 400 is easy to fabricate through processes like forging, rolling, welding, and machining. Welded joints retain the alloy’s corrosion resistance and mechanical strength, ensuring consistent performance in assembled components.​.
• Non-Magnetic Property — This alloy is non-magnetic, which is crucial for applications in electronic equipment, magnetic resonance imaging (MRI) facilities, and other environments where magnetic interference must be avoided.​.

Typical applications

• Marine Engineering — Widely used in seawater pipelines, ship propellers, marine pumps, and offshore platform components, as it resists corrosion from saltwater and marine organisms.​.
• Chemical Processing — Applied in chemical reactors, heat exchangers, storage tanks, and valves for handling corrosive chemicals (e.g., sulfuric acid, chlorine, and ammonia).​.
• Oil and Gas Industry — Used in oil well casings, drilling equipment, and pipeline systems for offshore and onshore oil/gas extraction, due to its resistance to sour gas (containing hydrogen sulfide) and brine.​.
• Electronics and Electrical Engineering — Utilized in electrical connectors, switchgear components, and MRI machine parts, thanks to its non-magnetic property and good electrical conductivity.​.
• Food Processing — Suitable for food processing equipment (e.g., mixers, tanks, and conveyors) because it is non-toxic, corrosion-resistant, and easy to clean, complying with food safety standards.​.