Power your offshore projects with flanges engineered to perform where others fail. Alloy 400 ASTM B546 Slip On Forged Flanges are designed specifically for the extreme demands of marine and offshore petroleum engineering – where corrosion, pressure, and reliability are non‑negotiable.
When your project is offshore, your margins for error are zero. Choose Alloy 400 ASTM B546 Slip On Forged Flanges that are engineered, tested, and trusted for demanding marine oil applications.
Alloy 400 (also known as Monel 400 or UNS N04400) is a nickel–copper alloy widely used for its excellent corrosion resistance, especially in seawater and acidic environments.
Its typical chemical composition is approximately:
• Nickel (Ni): 63.0% min
• Copper (Cu): 28–34%
• Iron (Fe): up to about 2.5%
• Manganese (Mn): up to about 2.0%
• Silicon (Si): up to about 0.5%
• Carbon (C): up to about 0.3%
• Sulfur (S): very low, usually max 0.024%
Key points that make Alloy 400 distinctive:
High nickel and copper content
The alloy is essentially a solid solution of nickel and copper, both of which are completely miscible. This gives it:
• Very good resistance to seawater and brine
• Excellent resistance to many acids and alkalis
• Good mechanical properties over a wide temperature range
Low impurity levels
Elements like carbon, sulfur, and silicon are tightly controlled at low levels to maintain:
• Good toughness
• Weldability
• Stable corrosion resistance
Standards and designations
You’ll often see Alloy 400 specified by:
• UNS: N04400
• W.Nr.: 2.4360 / 2.4361
• Trade name: Monel 400
If you are selecting an alloy for marine service, chemical processing, or oil & gas applications where chloride stress-corrosion cracking and general corrosion are concerns, the chemical composition of Alloy 400 is a strong reason it’s so widely trusted.