This chapter discusses the use of phase diagrams in alloy design, processing, and performance assessment. The examples cover both ferrous and nonferrous metals and a variety of goals and objectives. The chapter also identifies limitations and pitfalls associated with the use of phase diagrams.

This chapter provides information on the properties and behaviors of stainless steels and stainless steel powders. It begins with a review of alloy designation systems and grades by which stainless steels are defined. It then describes the composition, metallurgy, and engineering characteristics of austenitic, ferritic, martensitic, duplex, and precipitation hardening stainless steel powders and metal injection molding grades.

This chapter describes the various phases that form in tool steels, starting from the base of the Fe-C system to the effects of the major alloying elements. The emphasis is on the phases themselves: their chemical compositions, crystal structures, and properties. The chapter also provides general considerations of phases and phase diagrams and the determination of equilibrium phase diagrams. It describes the formation of martensite, characteristics of alloy carbides, and the design of tool steels.

Corrosion is a key subject for more or less all classes of alloys that fall within the broad definition of stainless steels because these alloys were developed with the intention of preventing corrosion. This chapter provides an introduction to the fundamentals of electrochemical theory as it pertains to corrosion resistance of stainless steels. The discussion provides an overview of electrochemical reactions, Faraday's law, the Nernst equation, galvanic versus electrochemical cells, corrosion tendency, and Pourbaix diagrams.

This chapter discusses the compositions, metallurgical phases, microstructure, heat treatment, grades, and structure-property relationships of steels. In addition, it describes the mechanisms involved in deformation, strengthening, and annealing of steels.

This chapter discusses the phase transformations of peritectic alloy systems. It describes the processes involved with equilibrium and nonequilibrium freezing, the mechanisms of peritectic formation, and the resulting microstructures. It also discusses the formation of peritectic structures in iron-base alloys and multicomponent systems.

Stainless steel retains strength and has excellent oxidation resistance from room temperature to nearly 1000 deg C relative to competitive materials. This chapter focuses on the high-temperature oxidation of stainless steel by oxygen or water vapor. It begins by discussing the thermodynamic conditions and electrochemical nature of oxidation and providing information on transient oxidation. This is followed by a description of Wagner's theory for metal oxidation. The volatile nature of Cr 2 O 3 is then reviewed. The chapter further discusses the causes and preventive measures of spalling and cracking of oxide scale. It ends with a section providing information on oxidation behaviors under less-oxidizing atmospheres.

This chapter discusses the construction, interpretation, and use of ternary phase diagrams. It begins by examining a hypothetical phase space diagram and several corresponding two-dimensional plots. It then describes one of the most basic tools of metallurgy, the Gibbs triangle, and explains how to construct tie lines to analyze intermediate compositions and phases. It also discusses the use of three-dimensional temperature-composition diagrams, three- and four-phase equilibrium phase diagrams, and binary and ternary phase diagrams associated with the iron-chromium-nickel alloy system.

This chapter introduces the basic ferrous physical metallurgy principles that need to be understood by the metallographer. The discussion focuses on the variations in microstructures that are generated as a result of the phase transformations that occur during both heat treatment (as in steels) and solidification (as in cast irons). The chapter describes how the development of the iron-carbon phase diagram, coupled with the understanding of the kinetics of phase transformations through the use of isothermal transformation diagram, were breakthroughs in the advancement of ferrous physical metallurgy. Several examples of the morphological features of microstructural constituents in steels are also presented.

This chapter discusses the alloy composition, metallurgy, mechanical behavior, stabilization, texture, anisotropy, high-temperature properties, and corrosion and oxidation resistance of ferritic stainless steels.

The existence of austenite and ferrite, along with carbon alloying, is fundamental in the heat treatment of steel. In view of the importance of structure and its formation to heat treatment, this chapter describes the various microstructures that form in steels, the various factors that determine the formation of microstructures during heat treatment processing of steel, and some of the characteristic properties of each of the microstructures. The discussion also covers the constitution of iron during heat treatment and the phases of heat-treated steel with elaborated information on iron phase transformation, hysteresis in heating and cooling, ferrite and austenite as two crystal structures of solid iron, and the diffusion coefficient of carbon.

Sulfur is one of the most common corrosive contaminants in high-temperature industrial environments and its presence can cause a number of problems, including sulfidation. This chapter describes the sulfidation behavior of a wide range of alloys as observed in three types of industrial environments. One environment consists of sulfur vapor, hydrocarbon streams, H2S, and H2-H2S gas; sulfides are the only corrosion products that form under these conditions. Another environment consists of H2, CO, CO2, H2S, and other gases, causing the formation of oxides as well as sulfides in most alloys. The third environment, for which less data exists, contains either SO2 or O2-SO2 mixtures.

This chapter covers the friction and wear behaviors of cast irons. It describes the microstructure and metallurgy of gray, white, malleable, and ductile cast irons, their respective tensile properties, and their suitability for applications involving friction, various types of erosion, and adhesive and abrasive wear.

Corrosion failures of welds can occur even when the proper base metal and filler metal have been selected, industry codes and standards have been followed, and welds have been deposited that possess full weld penetration and have proper shape and contour. This chapter describes some of the general characteristics associated with the corrosion of weldments. The role of macro- and microcompositional variations, a feature common to weldments, is emphasized in this chapter to bring out differences that need to be realized in comparing the corrosion of weldments to that of wrought materials. The discussion covers the factors influencing corrosion of weldments, microstructural features of weld microstructures, various forms of weld corrosion, and welding practice to minimize corrosion.

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 discusses the basic principles of alloying and their practical application in the production of titanium mill products and engineered parts. It begins with a review of the atomic and crystal structure of titanium and the conditions for interstitial and substitutional alloying. It then describes the different classes of alloying elements, their effect on mechanical properties and behaviors, and their influence on phase transitions and transformations. The chapter also discusses the role of intermetallic compounds and their effect on crystal structure and creep behavior.