This article discusses the steps in the primary processing of stainless steels: melting, refining, remelting, casting, and hot rolling. It provides information of the major categories of defects in hot rolled stainless steels, namely hot mill defects, inclusion-related defects, and hot ductility-related defects.

This chapter presents the primary considerations and mechanisms for corrosion and how they are involved in the selection of materials for process equipment in petroleum refineries and petrochemical plants. In addition, specific information on mechanical properties, corrosion, sulfide stress cracking, hydrogen-induced cracking, stress-oriented hydrogen-induced cracking, hydrogen embrittlement cracking, stress-corrosion cracking, velocity-accelerated corrosion, erosion-corrosion, and corrosion control is provided.

This chapter describes the basic steps in the steelmaking process. It explains how iron is reduced from ore in the liquid state through the classic blast furnace process and in the solid state by direct reduction. It discusses the conversion of iron to steel and the technological advancements that led from open hearth steelmaking to basic oxygen processes and ultimately the electric arc furnace (EAF). It describes the versatility, efficiency, and scalability of the EAF process and its impact on recycling and sustainability. It explains how EAF refining and deoxidation practices have changed over time, and describes secondary refining processes such as degassing, homogenization, rinsing, and remelting.

In castings, microstructural features are products of metal chemistry and solidification conditions. The microstructural features, excluding defects, that most strongly affect the mechanical properties or aluminum castings are size, form, and distribution of intermetallic phases; dendrite arm spacing; grain size and shape; and eutectic modification and primary phase refinement. This chapter discusses the effects of these microstructural features on properties and methods for controlling them. The chapter concludes with a detailed examination of the refinement of hypereutectic aluminum-silicon alloys.

In castings, microstructural features are products of metal chemistry and solidification conditions. The microstructural features, excluding defects, that most strongly affect the mechanical properties or aluminum castings are size, form, and distribution of intermetallic phases; dendrite arm spacing; grain size and shape; and eutectic modification and primary phase refinement. This chapter discusses the effects of these microstructural features on properties and methods for controlling them. The chapter concludes with a detailed examination of the refinement of hypereutectic aluminum-silicon alloys.

Almost all metals and alloys are produced from liquids by solidification. For both castings and wrought products, the solidification process has a major influence on both the microstructure and mechanical properties of the final product. This chapter discusses the three zones that a metal cast into a mold can have: a chill zone, a zone containing columnar grains, and a center-equiaxed grain zone. Since the way in which alloys partition on freezing, it follows that all castings are segregated to different categories. The different types of segregation discussed include normal, gravity, micro, and inverse. The chapter also provides information on grain refinement and secondary dendrite arm spacing and porosity and shrinkage in castings. It concludes with a brief overview of six of the most important casting processes in industries: sand casting, plaster mold casting, evaporative pattern casting, investment casting, permanent mold casting, and die casting.

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 examines the structural changes that occur in high-carbon steels during austenitization. It describes the effect of heating time and temperature on the production of austenite and the associated transformation of ferrite and cementite in eutectoid, hypoeutectoid, and hypereutectoid steels. It discusses the factors that influence the kinetics of the process, including carbon diffusion and the morphology of the original structure. It describes the nucleation and growth of austenite grains, the effect of grain size on mechanical properties, and the difference between coarse- and fine-grained steels. The chapter also discusses grain-refinement processes and some of the effects of overheating, including sulfide spheroidization, grain-boundary sulfide precipitation, and grain-boundary liquation.

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 discusses the similarities and differences of forging and forming processes used in the production of wrought superalloy parts. Although forming is rarely concerned with microstructure, forging processes are often designed with microstructure in mind. Besides shaping, the objectives of forging may include grain refinement, control of second-phase morphology, controlled grain flow, and the achievement of specific microstructures and properties. The chapter explains how these objectives can be met by managing work energy via temperature and deformation control. It also discusses the forgeability of alloys, addresses problems and practical issues, and describes the forging of gas turbine disks. On the topic of forming, the chapter discusses the processes involved, the role of alloying elements, and the effect of alloy condition on formability. It addresses practical concerns such as forming speed, rolling direction, rerolling, and heat treating precipitation-hardened alloys. It presents several application examples involving carbide-hardened cobalt-base and other superalloys, and it concludes with a discussion on superplasticity and its adaptation to commercial forging and forming operations.

This article discusses the composition, structures, properties, and behaviors of aluminum alloys and explains how they correspond to specific alloying elements. It begins with an overview of the general characteristics of wrought and cast aluminum alloys, the four-digit classification system by which they are defined, and the applications for which they are suited. It then explains how primary alloying elements, second-phase constituents, and impurities affect yield strength, phase formation, and grain size and how they induce structural changes that help refine certain alloys. The article also explains how primary alloying elements affect corrosion and wear behaviors and how they influence fabrication processes such as forming, forging, welding, brazing, and soldering.

Hot isostatic pressing (HIP) is a process refinement available to address internal porosity in castings. The HIP process may be used, in particular, for applications requiring very high quality and performance. This chapter discusses the principles, advantages, and disadvantages of HIP. It describes the effect of HIP on tensile properties and on the fatigue performance of aluminum alloy castings. In addition, the chapter discusses the processes involved in radiographic inspection of HIP-processed castings.

This chapter reviews weld corrosion in three key application areas: petroleum refining and petrochemical operations, boiling water reactor piping systems, and components used in pulp and paper plants. The discussion of each area addresses general design and service characteristics, types of weld corrosion issues, and prevention or mitigation strategies.

Hot isostatic pressing (HIP) is a process refinement available to address internal porosity in castings. The HIP process may be used, in particular, for applications requiring very high quality and performance. This chapter discusses the principles, advantages, and disadvantages of HIP. It describes the effect of HIP on tensile properties and on the fatigue performance of aluminum alloy castings. In addition, the chapter discusses the processes involved in radiographic inspection of HIP-processed castings.

Carbon and low-alloy steels in high-temperature service are vulnerable to the effects of hydrogen attack, which include severe loss in tensile and rupture strengths as well as ductility. As the chapter explains, when steel is in contact with hydrogen molecules at elevated temperatures, hydrogen atoms can be absorbed at the surface and then diffuse into the metal. Hydrogen atoms in the metal then react with iron carbide forming methane gas which can accumulate at grain boundaries and other interfaces. The chapter describes two applications, one in coal-fired boilers, the other in petroleum refining, where hydrogen attack was observed. It documents the extent of the damage in each case and identifies the source of the hydrogen.

The discovery and use of materials have shaped civilization since ancient times. This chapter traces the history of the use of metals from hammered copper estimated to be 11,000 years old to the development of electrolytically refined aluminum in 1884. The discussion covers the advent of the Bronze Age, extraction of metals from their respective ores, and the discovery of modern metals such as chromium, vanadium, platinum, and titanium.

This chapter describes the designations of carbon and low-alloy steels and their general characteristics in terms of their response to hardening and mechanical properties. The steels covered are low-carbon steels, higher manganese carbon steels, boron-treated carbon steels, H-steels, free-machining carbon steels, low-alloy manganese steels, low-alloy molybdenum steels, low-alloy chromium-molybdenum steels, low-alloy nickel-chromium-molybdenum steels, low-alloy nickel-molybdenum steels, low-alloy chromium steels, and low-alloy silicon-manganese steels. The chapter provides information on residual elements, microalloying, grain refinement, mechanical properties, and grain size of these steels. In addition, the effects of free-machining additives are also discussed.

This chapter describes the general characteristics of major types of steel annealing, including the process of normalization, which is a process that refines or normalizes the microstructure of steel. The first part of the chapter begins with an overview of the three-stage process of recovery, recrystallization, and grain growth. This is followed by discussions on annealing processes, namely subcritical annealing, critical-range annealing, full annealing, isothermal annealing, annealing for microstructure, and solution or quench annealing. Next, the chapter describes two undesirable reactions that occur during annealing: decarburization and scaling. Information on the gases and gas mixtures used for controlled atmospheres is then provided. The second part of the chapter focuses on the processes involved in normalizing, along with information on furnace equipment for normalizing. In addition, the chapter includes information on processes involved in induction heating of steel.

This chapter discusses the equipment and processes used to convert titanium billet and bar into useful shapes or more refined product forms. These secondary working operations include open-die, closed-die, hot-die and isothermal forging as well as ring rolling and extruding. The chapter describes each method in detail and how it affects the microstructure and mechanical properties of various titanium alloys. It also discusses the propensity of titanium to react with oxygen and hydrogen when heated and explains how to mitigate the effects.

This chapter describes the basic steps in the production of titanium ingots and their subsequent conversion to standards product forms. It explains how titanium ore is reduced to a spongy residue, then granularized, compacted, and melted (along with alloying additions) to form an ingot, which may be remelted several times to achieve the necessary properties. It also discusses the cause of defects and ingot imperfections and the benefits of billet reduction and grain-refinement processes.