The term Monel® is the registered trade mark of the International Nickel Company, Inc. for a series of nickel-copper alloys. The nominal composition of Monel® is 67% nickel, 30% copper, 1.7% iron, 1.1% manganese, with small residuals (< 0.1%) of carbon and silicon. Monel® is used where high strength and resistance to corrosion are required. It is useful against many common corrosives, such as sea water, dilute sulfuric acid and strong caustic solutions. It should not be used in sulfurizing atmospheres above 370°C (700°F) or with strong oxidizing acids such as nitric acid.
Welding. Commercial nickel alloys, including Monel®, that contain 30 to 45% copper, are tough and ductile. Except for free-machining (high-sulfur) alloys, these alloys are readily joined by welding, brazing, and soldering, with proper precautions. See NICKEL ALLOY WELDING.