This article discusses the general welding characteristics and metallurgical welding considerations that play an important function during the welding of nickel, nickel-copper, nickel-chromium, and nickel-chromium-iron alloys.

This article discusses the methods for producing powder metallurgy (PM) nickel powders, including carbonyl process, hydrometallurgical process, hydrogen reduction process, and atomization process, as well as their applications. It describes three processes for producing nickel alloy powders: water atomization, high-pressure water atomization, and gas atomization. The article also provides information on the applications of PM hot isostatic pressing in the oil and gas industry.

This article reviews the corrosion behavior in various environments for seven important nickel alloy families: commercially pure nickel, Ni-Cu, Ni-Mo, Ni-Cr, Ni-Cr-Mo, Ni-Cr-Fe, and Ni-Fe-Cr. It examines the behavior of nickel alloys in corrosive media found in industrial settings. The corrosive media include: hydrochloric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, hydrobromic acid, nitric acid, organic acids, salts, seawater, and alkalis. The modes of high-temperature corrosion include oxidation, carburization, metal dusting, sulfidation, nitridation, corrosion by halogens, and corrosion by molten salts. Applications where the corrosion properties of nickel alloys are important factors in materials selection include the petroleum, chemical, and electrical power industries. Most nickel alloys are much more resistant than the stainless steels to reducing acids, such as hydrochloric, and some are extremely resistant to the chloride-induced phenomena of pitting, crevice attack, and stress-corrosion cracking (to which the stainless steels are susceptible). Nickel alloys are also among the few metallic materials able to cope with hot hydrofluoric acid. The conditions where nickel alloys suffer environmentally assisted cracking are highly specific and therefore avoidable by proper design of the industrial components.

Nickel and nickel-base alloys are vitally important to modern industry because of their ability to withstand a wide variety of severe operating conditions involving corrosive environments, high temperatures, high stresses, and combinations of these factors. This article discusses the mining and extraction of nickel and describes the uses of nickel. It discusses the categories of nickel-base alloys, including wrought corrosion-resistant alloys, cast corrosion-resistant alloys, heat-resistant alloys (superalloys), and special-purpose alloys. The article covers the corrosion resistance of nickel with the inclusion of varying alloying elements. It provides useful information on the behavior of nickel and nickel alloys in specific environments describes its corrosion resistance in certain acids, alkalis, and salts.

This article discusses the procedures used for pickling nickel and nickel alloys. Nickel alloys can be divided into four groups: high-nickel alloys, nickel-copper alloys, nickel-chromium alloys, and nickel-iron-chromium alloys. Alloys within each composition group that has similar surface conditions are pickled in the same solutions using the same procedures. The article discusses three different surface conditions for pickling these nickel alloys: bright annealed white surface requiring removal of tarnish by flash pickling; bright annealed oxidized surface requiring removal of a layer of reduced oxide, sometimes followed by a flash pickle to brighten; and black or dark-colored surface requiring removal of adherent oxide film or scale. The article also reviews specialized pickling operations of nickel alloys and various cleaning and finishing operations, including grinding, polishing, buffing, brushing, and blasting.

Nickel in elemental form or alloyed with other metals and materials has made significant contributions to our present-day society and promises to continue to supply materials for a demanding future. This article provides a historical overview and physical metallurgy of nickel and nickel alloys. It lists and describes the compositions, mechanical and physical properties, and applications of commercial nickel and its alloys. The article briefly explains the forms of corrosion resulting from the exposure of nickel alloys to aqueous environments. It provides valuable information on the commercial forms of nickel alloys, namely, nickel-copper alloys, nickel-chromium and nickel-chromium-iron series, iron-nickel-chromium alloys, controlled-expansion alloys, nickel-iron low-expansion alloys, soft magnetic alloys, and welding alloys.

Nickel-base alloys can be machined by techniques that are used for iron-base alloys. This article discusses the effects of distortion and microstructure on the machinability of nickel alloys. It tabulates the classification of nickel alloys based on machining characteristics. The article describes the machining operations performed on nickel alloys, such as turning, planing and shaping, broaching, reaming, drilling, tapping and threading, milling, sawing, and grinding. It provides information on the cutting fluids used in the machining of nickel alloys. The article also analyzes nontraditional machining methods that are suitable for shaping high-temperature, high-strength nickel alloys. These include electrochemical machining, electron beam machining, and laser beam machining.

This article explains how to prepare nickel-base alloys for metallographic examination and identifies related processing and imaging challenges. It describes sectioning, mounting, grinding, and polishing procedures along with alternative electropolishing processes. It also provides information on etching and examines the microstructure of Nickel 200, Nickel 270, Duranickel 301, Monel 400, Monel R-405, Monel K-500, and other nickel alloys.

Nickel-base alloy castings are widely used in corrosive-media and high-temperature applications. This article begins with a discussion on the compositions of corrosion-resistant nickel-base casting alloys and heat-resistant nickel-base casting alloys. It describes the effects of aluminum and titanium on the structure and properties of nickel-base alloys. The article provides information on the melting, foundry, and pouring practices for nickel-base alloys. It explains the welding and heat treatment of the nickel-base casting alloys. The article concludes with an overview of the numerous applications of cast heat-resistant nickel-base alloys.

Electroforming is the process by which articles or shapes can be exactly reproduced by electrodeposition on a mandrel or form that is later removed, leaving a precise duplicate of the original. This article discusses electroforming applications, and explains electroforming of nickel, cobalt, iron, and copper, providing information on mandrel design and selection, electroforming solutions and operating variables. It discusses the significant aspects of electroforming that demand special considerations, such as metal distribution, internal deposit stress, roughness, and treeing. The article concludes with an overview of alloy electroforming.

This article is a compilation of binary alloy phase diagrams for which nickel (Ni) is the first named element in the binary pair. The diagrams are presented with element compositions in weight percent. The atomic percent compositions are given in a secondary scale. For each binary system, a table of crystallographic data is provided that includes the composition, Pearson symbol, space group, and prototype for each phase.

This article discusses the process considerations and deposit properties of nickel plating. It describes the Watts solution and the anode materials used. The article focuses on the nickel plating processes used for decorative, engineering, and electroforming purposes. It provides information on the quality control of nickel plating. It concludes with a review of the environmental, health, and safety considerations associated with nickel plating.

This article describes the factors to be considered while performing electroforming process. The factors include the shape and size of the mold, expected durability of the mold, required delivery time, and manufacture and cost of the necessary mandrel. The article discusses mandrel fabrication by either the use of fiberglass/resins or by the machining of the mandrel directly from computer-aided design data. It provides a comparison of nickel and other tooling materials in terms of coefficients of thermal expansion, thermal cycles for compression molding, and thermal cycles for metal autoclave molds.

This article is an atlas of fractographs that covers nickel-base superalloys. The fractographs display the following: hydrogen-embrittlement fracture; segment of a fractured second-stage gas-turbine wheel; gas-producer turbine rotor cast; dendritic stress-rupture fracture surface; fatigue and creep fractures; simultaneous metallographic-fractographic evaluation; and effect of thermal cycling on fatigue fracture.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of nickel alloys and in identifying and interpreting the morphology of fracture surfaces. The fractographs illustrate the fatigue crack, transgranular cleavage, intergranular fracture, grain boundaries, notch and fatigue precrack, dimpled rupture, and fatigue striations of these alloys.

The two major types of beryllium-containing alloys are copper-berylliums and nickel-berylliums. The most widely used beryllium-containing alloys are wrought copper-berylliums, which provide good strength while retaining useful levels of electrical and thermal conductivity. This article provides information on the specimen preparation procedures, macroexamination, microexamination, and microstructures of beryllium, copper-beryllium alloys, as well as nickel-beryllium alloys. It also discusses health and safety measures associated with the specimen preparation of beryllium and beryllium-containing alloys.

Forging of nickel-base alloys results in geometries that reduce the amount of machining to obtain final component shapes and involves deformation processing to refine the grain structure of components or mill products. This article discusses the heating practice, die materials, and lubricants used in nickel-base alloys forging. It describes two major forging processing categories for nickel-base alloys: primary working and secondary working categories. Primary working involves the deformation processing and conversion of cast ingot or similar bulk material into a controlled microstructure mill product, such as billets or bars, and secondary working refers to further forging of mill product into final component configurations.

This article discusses fracture, fatigue, and creep of nickel-base superalloys with additional emphasis on directionally solidified and single-crystal applications. It analyzes the physical metallurgy of these alloys. The effects of grain boundary and grain size on failure are summarized. The article also discusses the effects of microstructure and extrinsic parameters on fatigue crack propagation (FCP). It details the modeling of FCP rates and creep and creep-fatigue crack growth rates.