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Nonferrous Alloys
Published in Zainul Huda, Metallurgy for Physicists and Engineers, 2020
Nickel and its alloys have excellent high-temperature strength and corrosion resistance. Nickel metal has a low coefficient of thermal expansion; and finds application in bimetallic (iron-nickel) thermocouple sensors. Monel metal is a nickel-copper alloy that is resistant to corrosion in many environments. Monel 400 contains at least 63% Ni, 30% Cu, 2.3% Fe, and 1.8% Mn. It is one of the few alloys that maintains its strength at sub-zero temperatures. The most important engineering Ni alloy is the superalloy; which refers to Ni-base alloys containing Cr, Fe, Mo, W, Ti, Al, C, Ta, Zr, Nb, B, etc. Superalloys are known for their exceptional high-temperature strength and resistances to creep and hot corrosion; these remarkable properties render Ni-base superalloys suitable for applications in hot-section components (vanes, disks, and blades) of gas-turbine (GT) engines as well as in nuclear reactors. In particular, directionally solidified (DS) superalloy blades with exceptional creep resistance are used in modern aircraft engines (see Figure 2.9, Chapter 2). Several Ni-base superalloys have been developed for application in the GT blades; these include: the GTD-111, the Allvac 718Plus, and the single crystal superalloys Rene-N6 and MC-534 (Huda, 2017).
Gaskets in Flanged Joints
Published in Heinz K. Müller, Bernard S. Nau, Fluid Sealing Technology, 2019
Heinz K. Müller, Bernard S. Nau
Metal sheet gaskets are made in a wide range of ductile metals, usually annealed. These include aluminum, copper, and even silver, while for greater chemical resistance nickel or Monel™ may be used, or stainless steel if sufficient bolt load is available. For extreme conditions more exotic metals can be considered, such as titanium and Inconel™. The disadvantage of this type of gasket is that they tend to require high bolt loads and correspondingly heavy flanges and bolting. Initial gasket stress required is typically in the range 70–200 MPa. This problem can be alleviated by providing a surface layer of compliant material, such as PTFE or expanded graphite. On the plus side, flat metal gaskets offer high strength and a wide range of compatibility options. Generally however one of the following types is likely to be preferred.
The Nickel Alloys
Published in Mario Di Giovanni, Flat and Corrugated Diaphragm Design Handbook, 2017
The Monel nickel-copper alloys are more resistant than nickel to corrosion under reducing conditions and more resistant than copper to corrosion under oxidizing conditions. Hence they are in general more corrosion-resistant than either of their two principal constituents. Monels are highly resistant to atmospheric corrosion, salt water, and neutral and alkaline salts such as Chlorides, carbonates, Sulfates, nitrates, and acetates. Monel alloy 400 is one of the few materials that may be used to handle hydrochloric and hydrofluoric acids in specific concentrations. They are severely attacked by nitric and sulfurous acids.
Effect of Cryo-treatment of wires on machining performance of WEDM
Published in Materials and Manufacturing Processes, 2023
N.E. Arun Kumar, M. Ganesh, A. Suresh Babu, R. Elakkiyadasan
Monel 400 is selected as the workpiece material. Monel is a nickel–copper alloy increasingly used in heat exchangers in industries. It has a hardness value of 75 HRC. It is particularly resistant to salt as well as caustic substances, along with seawater and high-temperature steam. It has good weldability, moderate-to-high strength, and strong overall corrosion resistance.It shows resistance to corrosion in a wide range of chemical and marine conditionsfrom pure water to mineral acids, salts, and alkalis. This alloy has stronger resistance to reducing media than oxidizing media, more resistance to nickel under reducing conditions, and greater resistance to copper under oxidizing conditions. It also has good mechanical qualities from below zero temperatures up to roughly 480°C. Three cutting tools were used in this work, namely brass, molybdenum, and cryogenic-treated brass. Cryogenic treatment was done for 24 h at −196°C. The wire is wound on a stainless steel rod and held in a container containing liquid nitrogen for 24 h to achieve that extremely low temperature, which improves the wear resistance of the brass wire material. The cryogenically treated wire will have good wear resistance and increased hardness value, but the brittle nature will also get increased. Properties of the wire used in WEDM are listed in Table 1.
An advanced dislocation density-based approach to model the tensile flow behaviour of a 64.7Ni–31.96Cu alloy
Published in Philosophical Magazine, 2022
Alen S. Joseph, Pulkit Gupta, Nilesh Kumar, Maria C. Poletti, Surya D. Yadav
Monel 400 (64.7Ni–31.96Cu alloy) is a single phase, medium stacking fault energy (SFE) alloy [1] having FCC crystal structure that can gain strength by solid solution hardening, deformation hardening and grain size reduction [2]. The alloy’s good strength, excellent toughness, and outstanding corrosive characteristics make it suitable for usage in corrosive environments [3]. Its corrosion resistance in fast-moving brackish or sea water, as well as good stress-corrosion cracking resistance in fresh waters, led to its widespread use in marine applications. Monel is preferred over cupro-nickels, due to its improved corrosion resistance under high flow conditions and resistance to cavitation and impingement. Other properties like high ductility, good weldability and good thermal conductivity also add significance to the use of this alloy. Other fields where it finds its applications are nuclear power plants, aerospace industries and chemical industries. Typical products are turbine blades, shafts, valves, pumps, fixtures and fasteners for marine uses, springs, tanks for storing gasoline, equipments for chemical processing units, crude petroleum stills, piping in boiler feed water heaters and desecrating heaters [4,5].
Experimental investigation on the effect of corrosion and erosion on the shell and tube-type heat exchanger
Published in International Journal of Ambient Energy, 2021
R. Siva, G. Mageshwaran, Sanjana Kallat, Jeya Jeevahan
Monel metal is a solid solution consisting of nickel–copper alloy that is resistant to corrosion in any type of environmental condition. It is of high strength and can only be hardened by cold working. Due to its resistance to deterioration, alloy is most often used in parts that are used in marine and process refineries. The process of choosing the material consists of a few tests for proof and for using these applications. The conducted tests are given as follows. Emission spectrometry testCorrosion testSalt spray testAbrasive wear testMagnification test