Computer simulation of microstructural evolution during hot rolling of steels is a major topic of research and development in academia and industry. This article describes the methodology and procedures commonly employed to develop microstructural evolution models to simulate microstructural evolution in steels. It presents an example of the integration of finite element modeling and microstructural evolution models for the simulation of metal flow and microstructural evolution in a hot rolling process.

This article explores the potential of through-process simulations of the development of microstructure, texture, and resulting properties during the thermomechanical processing of Al-Mn-Mg alloys, starting from the as-cast ingot to final-gage sheet. It provides an introduction of the thermomechanical production of aluminum sheet and, in particular, highlights the main effects governing the evolution of microstructure and texture. The simulation tools used to model the evolution of microchemistry, microstructure, and texture upon deformation and recrystallization of aluminum alloys are described. The article discusses the recrystallization behavior of alloy AA 3104 during the interstand times in between two consecutive hot rolling passes with the help of combined microstructure models.

Ring rolling is a process for creating seamless ring shaped components using specialized equipment and forming processes. This article provides information on the applications of ring rolling. It discusses the types of machines used for ring rolling, namely, vertical rolling machines, radial-axial horizontal rolling machines, four-mandrel mechanical table mills, three-mandrel table mills, and automatic radial-axial multiple-mandrel ring mills. The article provides a discussion on the process control technology and ancillary operations of ring rolling. It describes the methods of producing ring blanks and the various types of blanking and rolling tools used in ring rolling process. The article concludes with a discussion on rolled ring tolerances and machining allowances.

Thread rolling is a cold-forming process for producing threads or other helical or annular forms by rolling the impression of hardened steel dies into the surface of a cylindrical or conical blank. Methods that use cylindrical dies are classified as radial infeed, tangential feed, through feed, planetary, and internal. This article focuses on the capabilities, limitations, and machines used for these methods. It describes the three characteristics, such as rollability, flaking, and seaming, used in evaluating and selecting metals for thread rolling. The article explores the factors affecting die life and explains the effect of thread form on processing. It provides information on various fluids used in thread rolling to cool the dies and the work and to improve the finish on the rolled products. The article provides a comparison between thread rolling and cutting, as well as between thread rolling and grinding.

The primary objectives of the rolling process are to reduce the cross section of the incoming material while improving its properties and to obtain the desired section at the exit from the rolls. This article illustrates a rolling sequence for the fabrication of bars, shapes, and flat products from blooms, billets, and slabs. It describes two methods for shapes or sections: universal rolling and caliber rolling. The article provides information on two-high mills and three-high mills. Specialty mills for thin sheets, namely, the Sendzimir mill and planetary mill, are discussed. The article analyzes the components of a computer controlled system for high-speed mills. Steels and nonferrous materials are also discussed. The article concludes with information on the defects in flat, bar, or shaped products due to heating and rolling practices.

This article is a comprehensive collection of terms related to metalworking operations that produce shapes from forging, extrusion, drawing, and rolling operations.

Roll forging is a process for simultaneously reducing the cross-sectional area and changing the shape of heated bars, billets, or plates. This article provides an overview of the process capabilities, production techniques, machines and machine size selection considerations, and types of roll dies and auxiliary tools for the roll forging. It concludes with information on the production examples of roll forging.

The processing of steel involves five distinct sets of texture development mechanisms, namely, austenite deformation, austenite recrystallization, gamma-to-alpha transformation, ferrite deformation, and static recrystallization during annealing after cold rolling. This article provides an introduction on crystallographic textures. It discusses the effects of austenite rolling and recrystallization on the texture and transformation behavior of recrystallized austenite and deformed austenite. The article illustrates the overall summary of the rolling and transformation behavior. It details cold-rolling textures, annealing textures, and recrystallization textures of steel samples. The article concludes with a summary of texture development during cold rolling and annealing.

Metalworking is one of the three major technologies used to fabricate metal products. This article tabulates the classification of metal forming processes. It discusses different types of metalworking equipment, including rolling mills, ring-rolling machines, and thread-rolling and surface-rolling machines. The article outlines the significant characteristics of pressing-type machines: load and energy characteristics, time-related characteristics, and accuracy characteristics. It summarizes different specialized processes such as advanced roll-forming methods, equal-channel angular extrusion, incremental forging, and microforming. The article describes the thermomechanical processing of nickel- and titanium-base alloys and concludes with information on the advancements in process simulation.

Thermomechanical processing (TMP) refers to various metal forming processes that involve careful control of thermal and deformation conditions to achieve products with required shape specifications and good properties. This article describes TMP methods in producing hot-rolled steel and reviews how improvements in the strength and toughness depend on the synergistic effect of microalloy additions and on carefully controlled thermomechanical conditions. It discusses TMP variables and the general distinctions between conventional hot rolling and common types of controlled-rolling schedules. The article describes the metallurgical processes in grain refinement of austenite steel by hot working, such as recovery and recrystallization and strain-induced transformation. The grain refinement in high strength low alloy steel by alloy addition is also discussed. The article provides an outline on the key stages of deformation, and the required metallurgical information at each of these stages.

This article describes the roll forming of components of nickel, titanium, and aluminum alloys. The metallurgical characteristics of the roll formed components, such as macrostructures, microstructures, tensile strength, and stress rupture performance, are discussed. The article compares the resulting properties of roll formed and conventionally forged components.

A wide range of flow-formed open- and close-ended shapes are currently available in a variety of difficult-to-form materials, including titanium alloys and nickel-base super alloys. This article describes the two basic methods of flow forming that are characterized by the position of the rolls during the forming process. The flow forming methods include staggered-roll flow forming process and in-line flow-forming process. Typical mechanical properties of flow-formed materials in various conditions are summarized in a table. Proper process controls and subsequent product qualification tests are critical to assure optimal performance of the flow-formed tubular component. The article discusses the most commonly required process control parameters and the effects of forming speed and temperature in the flow forming process.

Control of grain flow is one of the major advantages of shaping metal parts by rolling, forging, or extrusion. This article shows the effects of anisotropy on mechanical properties. Cylindrical forgings commonly have a straight parting line located in a diametral plane. The alternate classes of parting lines are called either "straight" or "broken" for brevity. Regardless of whether draft is applied or natural, the forging will have its maximum spread or girth at the parting line. Proper placement of the parting line ensures that the principal grain flow direction within the forging will be parallel to the principal direction of service loading. The article reviews the mutual dependence of parting line and forging process. It provides a checklist for the forging designer that suggests a systematic approach for establishing parting line location. Finally, the article contains examples, with illustrations of parting line locations, accompanied by tables of design parameters.

This article outlines several polycrystal formulations commonly applied for the simulation of plastic deformation and the prediction of deformation texture. It discusses the crystals of cubic and hexagonal symmetry that constitute the majority of the metallic aggregates used in technological applications. The article defines the basic kinematic tensors, reports their relations, and presents expressions for calculating the change in crystallographic orientation associated with plastic deformation. It surveys some of the polycrystal models in terms of the relative strength of the homogeneous effective medium (HEM). The article analyzes the anisotropy predictions of rolled face-centered-cubic and body centered-cubic sheets and presents simulations of the axial deformation of hexagonal-close-packed zirconium. The applications of polycrystal constitutive models to the simulation of complex forming operations, through the use of the finite element method, are also presented.

This article contains nine tables that present useful formulas for deformation analysis and workability testing. The tables present formulas for effective stress, strain, and strain rate in arbitrary coordinates, principal, compression and tension testing of isotropic material. The article also provides formulas for flat rolling, conical-die extrusion, wire drawing, deep drawing of cups from sheet metal, and bending, and formulas for anisotropic sheet materials.

Open-die forging can be distinguished from most other types of deformation processes in that it provides discontinuous material flow as opposed to continuous flow. This article describes the equipment and auxiliary tools used in open-die forging. It discusses the production and practice of open-die forging, with some practical examples. The article illustrates macrosegregation in a large steel ingot and lists the forgeable alloys. It reviews the physical and mathematical models used in deformation modeling. The article explains the contour forging and roll planishing process. It inform that to ensure that forgings can be machined to correct final measurements, it is necessary to establish allowances, tolerances, and specifications for flatness and concentricity. The article also tabulates the allowances and tolerances for as-forged shafts and bars.

This article focuses on the effects of mechanical plasticity on workability; that is, process control of localized stress and strain conditions to enhance workability. It describes the nature of local stress and strain states in bulk forming processes, leading to a classification scheme, including testing procedures and specific process measurements, that facilitate the application of workability concepts. Using examples, the article applies these concepts to forging, rolling, and extrusion processes. The stress and strain environments described in the article suggest that a workability test should be capable of subjecting the material to a variety of surface strain combinations. By providing insights on fracture criteria, these tests can be used as tools for troubleshooting fracture problems in existing processes, as well as in the process development for new product designs.

Recovery, recrystallization, and grain growth are microstructural changes that occur during annealing after cold plastic deformation and/or during hot working of metals. This article reviews the structure of the deformed state and describes the changes in the properties and microstructures of a cold-worked metal during recovery stage. It discusses the recrystallization that occurs by the nucleation and growth of grains. The article also reviews the growth behavior of the grains, explaining that the grain growth can be classified into two types: normal or continuous grain growth and abnormal or discontinuous grain growth. It also examines the key mechanisms that control microstructure evolution during hot working and subsequent heat treatment. These include dynamic recovery, dynamic recrystallization, metadynamic recrystallization, static recovery, static recrystallization, and grain growth.

This article reviews the bulk deformation processes for various aluminide and silicide intermetallic alloys with emphasis on the gamma titanium aluminide alloys. It summarizes the understanding of microstructure evolution and fracture behavior during thermomechanical processing of the gamma aluminides with particular reference to production scaleable techniques, including vacuum arc and cold-hearth melting, isothermal forging, conventional hot forging, and extrusion. The selection and design of manufacturing methods, in the context of processing-cost trade-offs for gamma titanium aluminide alloys, are also discussed.

This article reviews the general aspects of product design and provides an overview of the manufacturing processes and their relationship to design, with an emphasis on deformation processes. It discusses the various classes of deformation processes to illustrate their impacts on product design while taking advantage of the benefits of deformation processing.