This chapter discusses the development and use of microstructure models for optimizing superalloy forging operations. It describes how the processes that control grain structure evolution during hot working were used in model formulation and compares predicted microstructures with experimental results.

This chapter discusses the use of finite-element modeling in forging design. It describes key modeling parameters and inputs, mesh generation and computation time, and process modeling outputs such as metal flow, strain rate, loading profiles, and microstructure. It also includes a variety of application examples.

This chapter provides an overview of the microstructure-property relationships associated with aluminum-silicon alloys. It includes information on commercial designations and grades, phase compositions, solidification paths, alloying elements, and intermetallic phases. It also provides solubility data and maps out the topics covered in subsequent chapters in the book.

Temperature and deformation gradients developed in the course of manufacturing can have undesired effects on the microstructures along their path; the two most common being residual stress and distortion. This chapter discusses these manufacturing-related problems and how they can be minimized by heat treatments. It also provides information on residual stress evaluation and prediction techniques.

This appendix includes selected references on topics related to the production and application of superalloys, including properties and microstructure; melting/ingot breakdown; forging/powder metallurgy; machining, heat treating, joining, refurbishment/repair; investment casting; coatings/corrosion; and modeling.

This chapter is a brief account of various factors pertinent to the development of an engineering component. The discussion covers the disciplines and interactions of design development, engineering of component design, validation of design and process analysis, and matrix of design and manufacturing elements.

This chapter discusses the use of finite-element methods for modeling cold forging processes. The discussion covers process modeling inputs, such as geometric parameters, material properties, and interface conditions, and includes several application examples.

This chapter focuses on key requirements for obtaining third-generation advanced high-strength steels (AHSS). The discussion covers the microstructure design for AHSS, novel AHSS processing routes, the development of nanostructured AHSS, and the development of third-generation AHSS by the Integrated Computational Materials Engineering approach.

Hot stamping is a forming process for ultrahigh-strength steels (UHSS) that maximizes formability while minimizing springback. This chapter covers several aspects of hot stamping, including the methods used, the effect of process variables, and the role of finite-element analysis in process development and die design. It also discusses heating methods, cooling mechanisms, and the role of coatings in preventing oxidation.

This chapter examines the stress-corrosion cracking (SCC) failure of stainless steel pipe welds in boiling water reactor (BWR) service. It explains where most of the failures have occurred and provides relevant details about the materials of construction, fabrication techniques, environmental factors, and cracking characteristics. It includes a model that accounts for the primary factors involved in intergranular SCC, namely, tensile stresses above the yield stress of the base material, a sensitized microstructure, and reactor cooling water. The chapter also provides proven remedies and mitigation techniques corresponding to a wide range of issues related to stress, sensitization, and operating conditions.

Strain-range partitioning is a method for assessing the effects of creep fatigue based on inelastic strain paths or strain reversals. The first part of the chapter defines four distinct strain paths that can be used to model any cyclic loading pattern and describes the microstructural damages associated with each of the four basic loading cycles. The discussion then turns to fatigue life prediction for different types of materials and more realistic loading conditions, particularly those in which hysteresis loops have more than one strain-range component. To that end, the chapter considers two cases. In one, the relationship between strain range and cyclic life is established from test data. In the other, a rule is required to determine the damage of each concurrent strain and the total damage of the cycle is used to predict creep-fatigue life. The chapter presents several such damage rules and discusses their applicability in different situations.

This chapter discusses the context in which metallography is used and some of the challenges of analyzing three-dimensional structures from a two-dimensional perspective. It describes the hierarchical nature of metals, the formation of grain boundaries, and the notable characteristics of microstructure. It explains how microstructure can be represented qualitatively by points, lines, surfaces, and volumes associated to a large extent with grain contact, and how qualitative features (including grains) can be quantified based on cross-sectional area, volume fraction, density, distribution, and other such metrics.

The modeling and simulation activities in the field of high-pressure cold spray can be divided into two main parts: solid mechanics and fluid dynamics. This chapter focuses on these parts of modeling work in cold spray research. The discussion covers the objective, principal concepts, methods, and outcome of modeling and simulation of particle impact and of in-flight history of particles in cold spraying. The concept of integration of particle impact and fluid flow modeling to optimize cold spray deposition for a given material is also explained.

This chapter discusses the effect of composition and cooling rate on the microstructure and properties of cast irons and explains how they differ from steel. It describes the conditions under which white, gray, mottled (chilled), and nodular (ductile) cast irons are produced, and examines the growth mechanisms and structural details that set them apart. It also discusses the formation of compacted (vermicular) graphite and malleable iron, and compares and contrasts the composition, properties, and heat treatment of whiteheart and blackheart malleable types.

This chapter provides information on comparative attributes of sand molds and metal molds for aluminum casting. The cooling rates and microstructures obtained with each mold type are discussed. In addition, the chapter explains why sand castings work successfully in certain applications.

This chapter provides an overview of a computational method, called CALPHAD, used for the study of phase equilibria in multicomponent systems. It describes the thermodynamic models and calculation techniques employed in the software and explains how it applies to complex alloys used in industry. It also provides examples showing how CALPHAD has been used to determine the formability of metallic glass, calculate the dilation of stainless steel during phase transformation, and predict the beta transus and approach curves of commercial titanium alloys.

This chapter provides information on ultra-light steel family research programs conducted by the global steel industry under the umbrella of WorldAutoSteel. It discusses the collaboration efforts between U.S government, industry, and academia on advanced high-strength steels (AHSS) technology. Some of the projects on AHSS research and development are also reviewed.

This chapter provides a classification of the types of microstructural changes and transformations and then reviews each type. It presents the Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation and explains the thermodynamics of eutectic solidification and eutectoid transformation. An appendix covers growth of eutectoid structure in carburized pearlite.