Guide to Monel 400: Insights and Advantages

When manufacturing end use applications that will be used in extreme environments such as those which need to withstand extreme temperatures, high pressure or incredibly corrosive environments, selecting an alloy that is up to that task is critical. Monel 400 is a Nickel-Copper alloy that can be generally characterized as having good corrosion resistance, good weldability, and moderate to high strength. It is resistant to sea water and steam at high temperatures as well as caustic solutions and salt.

It is ideal for applications used in oil refineries throughout the world and it is widely used in the chemical and marine industries as well. In the past, the oil and the gas industry relied on what are typically considered low end corrosion resistant alloys. Over the last decade or so, this industry has adopted more advanced materials to reduce failure experienced over time in their equipment and parts. The cost impact of overcoming the downtime inducing effects of corrosion, pressure and extreme temperature, as well as failure-rate & safety, prompted this industry to look for materials like Monel 400 which offered increased reliability in harsh conditions.

Monel alloy’s good corrosion resistance and high strength properties also make it a great option in marine engineering, piping, cabling, chemical processing, as well as a variety of other applications depending upon what form it is used in. Being a resistant alloy, Monel 400 stands up to high temperature steam atmospheres and rapidly flowing brackish/sea water, while also maintaining excellent resistance to stress corrosion cracking in most freshwaters. It is useful in temperatures up to 1000°F (538°C) so with its anti-corrosive properties and toughness, can be an ideal choice of alloy for very unique needs and applications.

What is Monel 400 made of?

As a Nickel-Copper alloy, Monel 400 is a binary alloy, also known as a “puritan alloy”. What this means is that the proportions of nickel and copper are equal to that of the natural ore extracted from the Sudbury mines in Ontario, Canada. The alloy was created by the International Nickel Company in 1901 and it was named after their company president Ambrose Monell, but because trademarks are not allowed to carry a family name, they created their own loophole by simply removing the “L” at the end. Now, the Monel 400 trademark is owned by Special Metals Corporation and it is primarily composed of 52 – 67% nickel (Ni) and copper (Cu), with small amounts of iron, manganese, carbon, and silicon. In comparison to steels, it is extremely difficult to machine as it work hardens quickly.

Other chemical composition of Monel 400 includes:

Forms of Monel 400 Available

This alloy comes in a variety of forms and product lines such as rod and bar (sometimes known as 400 bar), but Ulbrich primarily supplies this alloy in strip and wire form. Due to its high strength, this Monel alloy can be used at lighter gauges and thicknesses for certain applications as compared to other nickel alloys or stainless steels. It can be produced in a wide variety of strip finishes and tempers; Monel 400 is also available in multiple shapes of wire including flat and round Monel wire.

Monel 400 Shaped Wire

There is great demand within the markets and applications we’ve talked about thus far for a corrosion resistant Nickel-Copper alloy in a variety of shapes and wire profiles. Cold-Rolled shaped wire is advantageous compared to other shaping methods because complex near net shapes, granular dimensional control, and exacting cross-sectional dimensions are achievable with almost no yield loss. These shapes are produced using a combination of rolling and drawing in order to produce near net shapes that can reduce costly machining further down the manufacturing process. Monel 400 from Ulbrich can still be supplied in not only shaped wire, but also strip and round wire in continuous coil form with close dimensional tolerances and no burr allowing manufacturers to run more coil, at faster speeds without worry. Many manufacturers working with Monel 400 shaped wire benefit from the fact that it can be easily joined and fabricated using conventional processes and procedures. Producing Monel in shaped wire profiles to specific physical properties is also very doable with the metallurgy staff available to advise on your specific applications.

Monel 400 vs. Comparable Stainless Steel

Stainless Steels and this Monel alloy can both be cold worked, but other than that many of their properties differ. Let’s look at an austenitic stainless steel with high corrosion resistance, 316 Stainless Steel. While their thermal expansion and specific heat capacity numbers are similar, Monel 400 has a maximum temperature of 1000 degrees Celsius, almost double that of 316 stainless (590 degrees Celsius). Also, this stainless alloy has very high corrosion resistance among the austenitic stainless, but the nickel alloy greatly surpasses it in this category as well. The combination of excellent resistance at high temperatures and excellent corrosion resistance make the Monel alloy a great selection for a variety of applications.

Applications

Monel 400, being known for its high strength and corrosion resistant properties, works in a wide range of temperatures and is available for use in a variety of products. Various Grades of Monel are used in a wide range of industries, from aerospace to marine applications. It is used extensively for piping as it is resistant to both steam and seawater atmospheres. More specifically, it’s toughness and anti-corrosive properties make it ideal for heavy duty applications like piping in the oil industry.

Other possible applications include heat exchangers, sea water scrubbers in gas systems, cladding, pumps and shafts in the chemical business, and more. Due to good mechanical properties from sub zero temperatures to nearly 1000°F, it can be used in a variety of atmospheres. Given that fact, Monel 400 is typically a more expensive alloy than stainless steel.

What are the other best uses for Monel 400?

• marine engineering
• chemical equipment
• hydrocarbon processing
• valves
• pumps
• fittings
• fasteners
• heat exchangers
• flexible metal hose

Next Steps

Whether you have specific questions about Monel 400 or any other alloy, feel free to contact an Ulbrich specialist anytime. Hopefully this article was able to increase your knowledge about when to choose Monel 400 for your applications and all the advantages of the Nickel-Copper alloy. Monel wire and strip are both options and can be offered in a wide variety of surface finishes, thicknesses and widths.