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 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.

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 describes the iron-carbon phase diagram, its modification by alloying elements, and the effect of carbon on the chemistry and crystallography of austenite, ferrite, and cementite found in Fe-C alloys and steels. It also lays the groundwork for understanding important metallurgical concepts, including solubility, critical temperature, dislocation defects, slip, and diffusion, and how they affect the microstructure, properties, and behaviors of steel.

This chapter discusses the mechanical properties of powder metal stainless steels and the extent to which they can be controlled through appropriate alloying and processing steps. It describes how process-related factors, such as porosity, interstitial content, sintering atmosphere, and heating and cooling profiles, affect strength, ductility, and corrosion resistance. It also provides an extensive amount of property data – including tensile and yield strength, elongation, hardness, and creep and stress rupture measurements as well as fatigue curves – for various grades of powder metal stainless steel.

This chapter describes the phases and constituents present in iron-carbon steels in near-equilibrium conditions. It explains how to use phase diagrams to predict and manage the development of ferrite, austenite, cementite, and pearlite through controlled cooling. It discusses the transformations, grain structure, and properties associated with each phase and identifies the primary stabilizing elements. It includes several micrographs revealing various microstructural features and describes the processing route by which they were achieved. It explains how to estimate the volume fraction of iron-carbon phases in equilibrium and how to determine the amount of each phase that must be present to reach a desired composition. The chapter also discusses the phases associated with hypo- and hyper-eutectoid steels and presents more than a dozen micrographs, identifying important structural features along with cooling conditions and sample preparation procedures.

Alloy steels are alloys of iron with the addition of carbon and one or more of the following elements: manganese, chromium, nickel, molybdenum, niobium, titanium, tungsten, cobalt, copper, vanadium, silicon, aluminum, and boron. Alloy steels exhibit superior mechanical properties compared to plain carbonsteels as a result of alloying additions. This chapter describes the beneficial effects of these alloying elements in steels. It discusses the mechanical properties, nominal compositions, advantages, and engineering applications of various classes of alloy steels. They are low-alloy structural steels, SAE/AISI alloy steels, high-fracture-toughness steels, maraging steels, austenitic manganese steels, high-strength low-alloy steels, dual-phase steels, and transformation-induced plasticity steels.

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

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.

The decomposition of austenite, during controlled cooling or quenching, produces a wide variety of microstructures in response to such factors as steel composition, temperature of transformation, and cooling rate. This chapter provides a detailed discussion on the isothermal transformation and continuous cooling transformation diagrams that characterize the conditions that produce the various microstructures. It discusses the mechanism and process variables of quenching of steel, explaining the factors involved in the mechanism of quenching. In addition, the chapter provides information on the causes and characteristics of residual stresses, distortion, and quench cracking of steel.

This chapter describes the metallurgy, composition, and properties of steels and other alloys. It provides information on the atomic structure of metals, the nature of alloy phases, and the mechanisms involved in phase transformations, including time-temperature effects and the role of diffusion, nucleation, and growth. It also discusses alloying, heat treating, and defect formation and briefly covers condenser tube materials.

Ferritic stainless steels are essentially iron-chromium alloys with body-centered cubic crystal structures. Chromium content is usually in the range of 11 to 30%. The primary advantage of the ferritic stainless steels, and in particular the high-chromium, high-molybdenum grades, is their excellent stress-corrosion cracking resistance and good resistance to pitting and crevice corrosion in chloride environments. This chapter provides information on the classifications, properties, and general welding considerations of ferritic stainless steels. The emphasis is placed on intergranular corrosion, which is the most common cause of failure in ferritic stainless steel weldments. Two case histories involving intergranular corrosion failures of ferritic stainless steel weldments are included. A brief discussion on hydrogen embrittlement is also provided.

This chapter discusses various alloying and processing approaches to increase the strength of low-carbon steels. It describes hot-rolled low-carbon steels, cold-rolled and annealed low-carbon steels, interstitial-free or ultra-low carbon steels, high-strength, low-alloy (HSLA) steels, dual-phase (DP) steels, transformation-induced plasticity (TRIP) steels, and martensitic low-carbon steels. It also discusses twinning-induced plasticity (TWIP) steels along with quenched and partitioned (Q&P) steels.

This chapter is dedicated mostly to the metallurgical effects on the corrosion behavior of corrosion-resistant alloys. It begins with a section describing the importance of alloying elements on the corrosion behavior of nickel alloys. The chapter considers the metallurgical effects of alloy composition for heat-resistant alloys, nickel corrosion-resistant alloys, and nickel-base alloys. This chapter also discusses the corrosion implications of changing the alloy microstructure via solid-state transformation, second-phase precipitation, or cold work. It concludes with a comparison of corrosion behavior between cast and wrought product forms.