Monel wire mesh- Excellent performance in Marine engineering

Monel wire mesh is an alloy of nickel (67%) and copper (23%) that has resistance to sea water and steam at high temperatures. Monel wire mesh is strong against de-aerated acids such as H2SO4 and HCL however it is affected by nitric acid & ammonia solutions due to high percentage of copper content.

There are various features of Monel wire meshthat makes it highly useful such as

·        Excellent weldability

·        High resistance to stress corrosion.

·        Low strength in annealed condition, usage of foreign elements and heat treatment helps to increase the strength.

·        Excellent mechanical properties at subzero temperature.

·        High yield & tensile strength.

There are numerous applications in which Monel wire mesh is found such as

·        Crude petroleum stills

·        Industrial heat exchangers

·        Marine engineering

·        Boiler feed water heaters and other heat exchangers

·        Chemical and hydrocarbon processing equipment

·        Valves, pumps, shafts, fittings, and fasteners

·        Crude oil distillation towers

·        Gasoline and freshwater tanks

·        Chlorinated solvents

·        De-aerating heaters

·        Process vessels & pipings

·        Electrical & electronic components

Monel alloy is widely used in marine engineering due to its resistance to corrosion. The corrosion rate of this alloy decreases sharply with increase in the nickel content. The corrosion of Monel 400 in naturally aerated and deaerated Arabian Gulf water (AGW) and 3.5 % NaCl solutions was studied. The work has been carried out using cyclic potentiodynamic polarization, chronoamperometric current-time, open-circuit potential, and electochemical impedance spectroscopy measurements along with scanning electron microscope (SEM) and energy dispersive X-Ray analyzer (EDX) investigations. Polarization data showed that AGW is more corrosive than 3.5% NaCl towards Monel and the deaeration process decreased the corrosion of Monel in both media. Chronoamperometric curves confirmed the results obtained by polarization measurements that the uniform and pitting corrosion of Monel 400 were reduced in the deaerated AGW and 3.5% NaCl solutions. Impedance spectra showed that the surface and polarization resistances recorded higher values in deaerated solutions. SEM/EDX investigations indicated that the corrosion of Monel 400 proceeds by the selective electrodissolution of nickel that allows copper enrichment on the surface of the alloy.

Monel 400 alloy is used in the desalination technology industry and other marine engineering fields due to its durability in natural seawater. 

Monel 400 alloy contains 60-70 percent nickel, 20-29 percent copper and small amounts of iron, manganese, silicon and carbon. A low corrosion rate in rapidly flowing brackish or seawater combined with excellent resistance to stress-corrosion cracking in most freshwaters, and its resistance to various corrosive conditions resulted in its use in marine applications such as valves & pumps (that are either submerged in sea water or frequently exposed to it), oil and chemical processing industries including non-oxidizing chloride solutions. The corrosion of a series of Copper and nickel alloys in natural sea water and in chloride solutions under different conditions are studied. Some authors have claimed that selective electrodissolution of nickel is predominant while others have found that copper dissolution depending on the composition of the alloy.