Monel 400 (UNS N04400)

Monel 400 (also specified as UNS N04400 / Werkstoff No. 2.4360) is a nickel-copper solid-solution strengthened alloy. It combines excellent corrosion resistance in seawater, salt solutions, hydrofluoric acid and alkaline media with good mechanical properties, outstanding toughness and easy fabricability. The alloy is non-magnetic and retains good ductility and toughness from sub-zero to moderately elevated temperatures.

Overview

• Category: Ni-Cu solid-solution strengthened alloy
• Standards: ASTM B127, B163, B165; AMS 4676; UNS N04400; DIN/EN 2.4360
• Available forms: Round bar / rod, plate, sheet, strip, pipe & tube, wire, forgings, and custom profiles to order

Chemical Composition (wt%)

Physical Properties

Mechanical Properties (typical, annealed)

Good toughness and excellent cold-workability.

Fabrication & Welding

• Hot working: 1000–1150 °C with uniform heating; air cool after working.
• Cold working: Excellent cold-formability with a low work-hardening rate; suitable for a wide range of cold-working operations.
• Welding: Good weldability by GTAW (TIG), resistance welding, SMAW (MMA) and other conventional processes.

Heat Treatment

• Annealing: Heat to 700–800 °C, hold, then air cool or water cool, to relieve fabrication stresses and improve ductility and toughness.
• Solution treatment: Heat to 1010–1065 °C and cool rapidly, to fully dissolve alloying elements and restore corrosion resistance and toughness.

Key Features

• Excellent corrosion resistance in seawater, salt solutions, organic acids and alkaline media;
• Outstanding resistance to hydrofluoric acid and fluorine gas;
• Good combination of strength and toughness;
• Excellent formability and machinability;
• Non-magnetic, suitable for applications where magnetism must be avoided.

Corrosion Resistance

• Excellent resistance to seawater, chloride salt solutions, organic acids and alkalis;
• Outstanding performance in hydrofluoric acid and fluorine-containing media;
• Reasonable tolerance of both reducing and oxidising acids.

Typical Applications

• Marine engineering: ship propellers, pump shafts, condenser tubes and desalination equipment;
• Chemical industry: reactors, piping, valves and pumps handling corrosive chemicals;
• Petroleum industry: oil tubing and storage tanks for extraction and refining;
• Food processing: food-contact components of processing equipment;
• Electrical & electronics: electronic components, wires and cables.

For detailed datasheets, mill certificates (EN 10204 3.1) or inquiries on specific sizes and tolerances, please contact our sales & engineering team.