This chapter discusses the compositions, mechanical properties, phase structure, stabilization, corrosion resistance, and advantages of austenitic stainless steels. Austenitic alloys are classified and reviewed in three groups: (1) lean alloys, such as 201 and 301, which are generally used when high strength or high formability is the main objective; (2) chromium nickel alloys used for high temperature oxidation resistance; and (3) chromium, molybdenum, nickel, and nitrogen alloys used for applications where corrosion resistance is the main objective.

This chapter explains how materials selection becomes much more difficult when designing for high-temperature corrosion environments. It also discusses the use of cladding and weld overlays to compensate for material deficiencies and prolong service life.

This article discusses the role of alloying in the production and use of common refractory metals, including molybdenum, tungsten, niobium, tantalum, and rhenium. It provides an overview of each metal and its alloys, describing the compositions, properties, and processing characteristics as well as the effect of alloying elements. It also discusses strengthening mechanisms and, where appropriate, corrosion behavior.

This article discusses the composition, structure, and properties of iron-nickel-, nickel-, and cobalt-base superalloys and the effect of major alloying and trace elements. It describes the primary and secondary roles of each alloying element, the amounts typically used, and the corresponding effect on properties and microstructure. It also covers mechanical alloying and weldability and includes nominal composition data on many wrought and cast superalloys.

This chapter describes the corrosion behavior of beryllium in gaseous atmospheres, including oxygen, nitrogen, carbon dioxide, and carbon monoxide. It also discusses the development of high-temperature corrosion-resistant beryllium alloys.

Nickel-base alloys used for low-temperature aqueous corrosion are commonly referred to as corrosion-resistant alloys (CRAs), and nickel alloys used for high-temperature applications are known as heat-resistant alloys, high-temperature alloys, or superalloys. The emphasis in this chapter is on the CRAs and in particular nickel-chromium-molybdenum alloys. The chapter provides a basic understanding of general welding considerations and describes the welding metallurgy of molybdenum-containing CRAs and of nickel-copper, nickel-chromium, and nickel-chromium-iron CRAs. It discusses the corrosion behavior of nickel-molybdenum alloys and nickel-chromium-molybdenum alloys. Information on the phase stability and corrosion behavior of nickel-base alloys is also included.

This chapter focuses on resistance characteristics and methods of protecting different forms of high-temperature gaseous corrosion, namely high-temperature oxidation, sulfidation, carburization, hydrogen effects, and hot corrosion.

This chapter compares and contrasts the high-temperature behaviors of metals and composites. It describes the use of creep curves and stress-rupture testing along with the underlying mechanisms in creep deformation and elevated-temperature fracture. It also discusses creep-life prediction and related design methods and some of the factors involved in high-temperature fatigue, including creep-fatigue interaction and thermomechanical damage.

This chapter is intended to identify materials, processes, and designs that will lead to great advances in powder-binder forming technologies. It discusses some of the structures obtained through these advances in powder-binder technologies such as binder jetting and extrusion-based additive manufacturing, including bound-metal deposition and fused-filament fabrication: oxidation-resistant high-temperature alloys, anisotropic structures, submicrometer-scale structures, surface hard materials, and artist metallic clays. Some of the advances discussed include the developments in process involving plastics, emulsions, ceramics, and porous structures and foams. Improvements in the design processes have led to the development of functional structures, controlled porosity, and bioinspired structures.

Nickel and nickel-base alloys are specified for many applications, such as oil and gas production, power generation, and chemical processing, because of their resistance to stress-corrosion cracking (SCC). Under certain conditions, however, SCC can be a concern. This chapter describes the types of environments and stress loads where nickel-base alloys are most susceptible to SCC. It begins with a review of the physical metallurgy of nickel alloys, focusing on the role of carbides and intermetallic phases. It then explains how SCC occurs in the presence of halides (such as chlorides, bromides, iodides, and fluorides), sulfur-bearing compounds (such as H2S and sulfur-oxyanions), high-temperature and supercritical water, and caustics (such as NaOH), while accounting for temperature, composition, microstructure, properties, environmental contaminants, and other factors. The chapter also discusses the effects of hydrogen embrittlement and provides information on test methods.

Titanium is a lightweight metal used in a growing number of applications for its strength, toughness, stiffness, corrosion resistance, biocompatibility, and high-temperature operating characteristics. This chapter discusses the applications, metallurgy, properties, compositions, and grades of commercially pure titanium and alpha and near-alpha, alpha-beta, and beta titanium alloys. It describes primary and secondary fabrication processes, including melting, forging, forming, heat treating, casting, machining, and joining as well as powder metallurgy and direct metal deposition. It also compares and contrasts the properties of wrought, cast, and powder metal titanium products and discusses corrosion behaviors.

Stainless steels and nickel-base alloys are recognized for their resistance to general corrosion and other categories of corrosion. This chapter examines the effects of specific alloying elements, metallurgical structure, and mechanical conditioning on the corrosion resistance of these alloys. Some categories of corrosion covered are pitting, crevice, intergranular, stress-corrosion cracking, general, and high-temperature corrosion.

This chapter is a collection of tables listing: cast alloy designations of Aluminum Association, along with their general applications; the chemical compositions of the frequently used alloys for gravity permanent molds, low-pressure permanent molds, squeeze castings, and die castings; the typical tensile properties of die cast alloys; and the designations of different heat treatments and their description. The tables also list the temperatures and times of typical heat treatment cycles for different permanent mold cast alloys; typical components in sand, gravity, and low-pressure permanent mold castings and die castings, the functional requirements of each process, and the corresponding suitable alloys and heat treatments; and alloys that are high vacuum die cast for structural castings. The chapter also presents examples of photomicrographs of some alloys cast by different processes.

This article examines the role of alloying in the production and use of nickel and its alloys. It explains how nickel-base alloys are categorized and lists the most common grades along with their compositional ranges and corresponding UNS numbers. It describes the role of nearly 20 alloying elements and how they influence strength, ductility, hardness, and corrosion resistance. It also addresses processing issues, explaining how alloying and intermetallic phases affect forming, welding, and machining operations.

This appendix contains several tables listing UNS numbers, common names, and descriptions of important titanium alloys and where they are typically used.

This chapter discusses some of the promising developments in the use of titanium, including titanium aluminides, titanium matrix composites, superplastic forming, spray forming, nanotechnology, and rapid solidification rate processing. It also reports on efforts to increase the operating temperature range of conventional titanium alloys and reduce costs.

This article discusses the properties, behaviors, and uses of cobalt and its alloys. It explains how cobalt alloys are categorized and describes the commercial designations and grades that are available. It also provides composition information and explains how alloying elements and carbides affect toughness, hardness, ductility, and strength as well as resistance to heat, corrosion, and wear.

Titanium alloys respond well to heat treatment be it to increase strength (age hardening), reduce residual stresses, or minimize tradeoffs in ductility, machinability, and dimensional and structural stability (annealing). This chapter describes the phase transformations associated with these processes, explaining how and why they occur and how they are typically controlled. It makes extensive use of phase diagrams and cooling curves to illustrate the effects of alloying and quenching on beta-to-alpha transformations and the conditions that produce metastable phases. It also examines several time-temperature-transformation diagrams, which account for the effect of cooling rate.

This chapter discusses the factors that govern the mechanical properties of titanium, beginning with the morphology of the alpha phase. It explains that the shape of the alpha phase has a significant effect on many properties, including hardness, tensile strength, toughness, and ductility as well as creep, fatigue strength, and fatigue crack growth rate. It also discusses the influence of other titanium phases and the properties of titanium-based intermetallic compounds, metal-matrix composites, and shape-memory alloys.

This chapter presents an overview of heat treating of nonferrous alloys. First, a brief discussion on the effects of cold work and annealing on nonferrous alloys is presented. This is followed by a discussion on the mechanisms involved in the more commonly used heat treating procedures for hardening or strengthening, namely solution treating and aging. Examples are presented for heat treating of two commercially important nonferrous alloys, one from the aluminum-copper system and one from the copper-beryllium system.