This chapter discusses the composition, alloying characteristics, mechanical properties, corrosion resistance, advantages, limitations, and applications of martensitic, semiaustenitic, and austenitic precipitation-hardenable stainless steels.

Precipitation hardening is used extensively to strengthen aluminum alloys, magnesium alloys, nickel-base superalloys, beryllium-copper alloys, and precipitation-hardening stainless steels. This chapter discusses two types of particle strengthening: precipitation hardening, which takes place during heat treatment; and true dispersion hardening, which can be achieved by mechanical alloying and powder metallurgy consolidation. It provides information on the three steps of precipitation hardening of aluminum alloys: solution heat treating, rapid quenching, and aging.

Stainless steels derive their name from their corrosion-resisting properties first observed in 1912. Two groups, working independently, concurrently discovered what came to be known as austenitic and ferritic stainless steels. Martensitic and precipitation-hardened stainless steels would be developed later. This chapter discusses each of these four major types of stainless steel and their respective compositions, properties, and uses. It explains how alloying, heat treating, and various hardening processes affect corrosion performance, and includes a detailed discussion on the optimization of martensitic stainless steels for cutlery applications.

This chapter takes a practical approach to the problem of stress-corrosion cracking (SCC) in stainless steels, explaining how different application environments affect different grades of stainless steel. It describes the causes of stress-corrosion cracking in chloride, caustic, polythionic acid, and high-temperature environments and the correlating effects on austenitic, ferritic, duplex, martensitic, and precipitation hardening stainless steels and nickel-base alloys. It also discusses the contributing effects of sensitization and hydrogen embrittlement and the role of composition, microstructure, and thermal history. Sensitization is particularly detrimental to austenitic stainless steels, and in many cases, eliminating it will eliminate the susceptibility to SCC. The chapter includes an extensive amount of data and illustrations.

This chapter provides a basis for understanding the influence of stainless steel alloy composition and metallurgy on the welding process, which involves complex dynamics associated with melting, refining, and thermal processing. It begins with an overview of the welding characteristics of the categories of stainless steels, namely austenitic, duplex, ferritic, martensitic, and precipitation-hardening stainless steels. This is followed by a discussion of the selection criteria for materials to be welded. Various welding processes used with stainless steel are then described. The chapter ends with a section on some of the practices to ensure safety and weld quality.

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.

Steels with chromium contents above 12% show high resistance to oxidation and corrosion and are generally designated as stainless steels. This chapter discusses the compositions, microstructures, heat treatments, and properties of martensitic, ferritic, austenitic, ferritic-austenitic (duplex), and precipitation hardening stainless steels. It also describes solidification sequences and explains how chromium carbides may segregate to grain boundaries at certain temperatures, making grain boundary regions susceptible to intercrystalline or intergranular corrosion.

This article covers the metallurgy and properties of stainless steels. It provides composition information on all types of ferritic, austenitic, martensitic, duplex, and precipitation-hardening stainless steels, including proprietary and nonstandard grades, along with corresponding property and performance data. It also discusses the effect of various alloying elements on pitting, crevice corrosion, sensitization, stress-corrosion cracking, and oxidation resistance.

This chapter discusses the classification, composition, properties, and applications of five types of stainless steels: austenitic, ferritic, duplex, martensitic, and precipitation-hardening steels. It discusses the process involved in argon oxygen decarburization that is used to refine stainless steel. The chapter also provides information on the classification and composition of stainless steel castings. It concludes with a brief description of the Schaeffler constitution diagram which is useful in predicting the type of stainless steel as a function of its alloy content.

This chapter discusses the processes involved in heat treating of stainless steels, providing information on the classification, chemical compositions, and corrosion resistance of stainless steels and the effect of specific elements on the characteristics of iron-base alloys. Five groups of stainless steels are discussed: austenitic, ferritic, martensitic, precipitation-hardening, and duplex grades. The chapter also describes the heat treatment conditions that should be maintained for processing of stainless steels.

This appendix contains tables listing the composition of austenitic, ferrite, martensitic, precipitation-hardenable, and duplex stainless steels and of Alloy Casting Institute heat- and corrosion-resisting casting alloys.

Steels that resist corrosive attack from normal atmospheric exposure and contain a minimum of 10.5% Cr and 50% Fe are generally classified as stainless steels. Their special qualities lie in a chromium-rich oxide surface film that quickly regrows when damaged. This chapter discusses the classification, composition, properties, treatments, and applications of austenitic, ferritic, martensitic, duplex, precipitation-hardening, powder metallurgy, and cast stainless steels. It also reviews the history of stainless steels and provides information on alloy designation systems.

This chapter discusses different thermal processes applicable to the various alloy groups of stainless steels, namely austenitic, ferritic, martensitic, precipitation hardening, and duplex stainless steels. The processes discussed include soaking, annealing, stress relieving, austenitizing, tempering, aging, and conditioning.

Stainless steels derive their name from their exceptional corrosion resistance, which is attributed to their finely tuned compositions. This chapter discusses the alloying elements used in stainless steels and the some of the processing challenges they present. One of the biggest challenges is that stainless steels cannot be hardened by heat treatment. As a result, they are highly sensitive to processing-induced defects and the formation of detrimental phases. The chapter explains how alloy design, phase equilibria, microstructure, and thermomechanical processing can be concurrently optimized to produce high-quality austenitic, ferritic, and duplex stainless steels.

This chapter focuses on the metallurgical factors governing the machinability of stainless steels. It begins by describing the chemistry, cleanliness, structure, processing history, and the cross-section size of the stock of the different grades of stainless steel. This is followed by a general description of the machining behavior of the stainless steel families, namely ferritic, martensitic, austenitic, precipitation hardening, duplex, and super stainless steels. The beneficial effect of controlled inclusions is then discussed. The chapter ends with a section providing information on high-speed tool steel and carbide tooling, along with tool coatings and coolants applicable to stainless steel.

This chapter discusses the composition and classification of stainless steels and focuses on the processes involved in heat treatment and applications of these steels. The wrought and the cast stainless steels covered are ferritic, austenitic, duplex (ferritic-austenitic), martensitic, and precipitation-hardening. In addition, information on special considerations for stainless steel castings is also provided. The heat treatment processes explained in the chapter are preheating, annealing, stress relieving, hardening, tempering, austenite conditioning, heat aging, and nitride surface hardening. Finally, some special considerations for stainless steel castings are discussed.

This appendix provides tensile property and fracture toughness data for various low-alloy and stainless steels.

During fusion welding, the thermal cycles produced by the moving heat source causes physical state changes, metallurgical phase transformations, and transient thermal stresses and metal movement. This chapter begins by discussing weld metal solidification behavior and the solid-state transformations of the main classes of metals and alloys during fusion welding. The main classes include work- or strain-hardened metals and alloys, precipitation-hardened alloys, transformation-hardened steels and cast irons, stainless steels, and solid-solution and dispersion-hardened alloys. The following section provides information on the residual stresses and distortion that remain after welding. The focus then shifts to distortion control of weldments. Inclusions and cracking are discussed in detail. The chapter also discusses the causes for reduced fatigue strength of a component by a weld: stress concentration due to weld shape and joint geometry; stress concentration due to weld imperfections; and residual welding stresses. Inspection and characterization of welds are described in the final section of this chapter.

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.

Hydrogen damage is a form of environmentally assisted failure that results most often from the combined action of hydrogen and residual or applied tensile stress. This chapter classifies the various forms of hydrogen damage, summarizes the various theories that seek to explain hydrogen damage, and reviews hydrogen degradation in specific ferrous and nonferrous alloys. The preeminent theories for hydrogen damage are based on pressure, surface adsorption, decohesion, enhanced plastic flow, hydrogen attack, and hydride formation. The specific alloys covered are iron-base, nickel, aluminum, copper, titanium, zirconium, vanadium, niobium, and tantalum alloys.