Recrystallization is to a large extent responsible for their final mechanical properties. This article commences with a discussion on static recrystallization (SRX) and dynamic recrystallization (DRX). The DRX includes continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX). The article discusses the assumptions and simplifications for the Avrami analysis. It describes the effects of nucleation and growth rates on recrystallization kinetics and recrystallized grain size based on the Johnson-Mehl-Avrami-Kolmogorov model for static recrystallization. The article reviews the kinetics of DRX with the aid of the Avrami relations. It considers the basic framework of the mesoscale approach for DDRX, including the three basic equations for grain size changes, strain hardening and dynamic recovery, and nucleation. The article explains the mesoscale approach for CDRX to predict microstructural evolutions occurring during hot deformation, along with an illustration of the main features of the CDRX mesoscale model.

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 summarizes the general features of microstructure evolution during the thermomechanical processing (TMP) of nickel-base superalloys and the challenges posed by the modeling of such phenomena. It describes the fundamentals and implementations of various modeling methodologies. These include JMAK (Avrami) models, topological models, and mesoscale physics-based models.

This article reviews the general aspects of microstructure evolution during thermomechanical processing. The effect of thermomechanical processing on microstructure evolution is summarized to provide insight into the aspect of process design. The article provides information on hot working and key processes that control microstructure evolution: dynamic recovery, static recovery, recrystallization, and grain growth. Some of the key phenomenological descriptions of plastic flow and microstructure evolution are also summarized. The article concludes with a discussion on the modeling of microstructure evolution.

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.

The systematic study of microstructural evolution during deformation under hot working conditions is important in controlling processing variables to achieve dimensional accuracy. This article explains the microstructural features that need to be modeled and provides an outline of the principles and achievements of each of the various microstructural models, including black-box modeling, gray-box modeling, white-box modeling, and hybrid modeling.

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 examines how cellular automaton (CA) can be applied to the simulation of static and dynamic recrystallization. It describes the steps involved in the CA simulation of recrystallization. These include defining the CA framework, generating the initial microstructure, distributing nuclei of recrystallized grains, growing the recrystallized grains, and updating the dislocation density. The article concludes with information on the developments in CA simulations.

This article describes the presses, transportation equipment, and manufacturing processes associated with cogging. It discusses the practical and metallurgical issues encountered during the conversion of ingot to billet. The article explains the use of numerical modeling as part of the continuing efforts to reduce the cost and time associated with developing new cogging sequences, increase the yield, make the processes more robust, and increase the quality of the produced product.

This article focuses on the modeling of microstructure evolution during thermomechanical processing in the two-phase field for alpha/beta and beta titanium alloys. It also discusses the mechanisms of spheroidization, the coarsening, particle growth, and phase decomposition in titanium alloys, with their corresponding equations.

This article emphasizes short-term tension and compression testing of metals at high temperatures. It describes the effect of temperature on deformation and strain hardening, occurrence of high-temperature creep in structural alloys, and the performing of mechanical testing for high-temperature structural alloys. The article discusses hot tension testing and measurements of temperature and strain in the hot tension testing. It also provides an overview of hot compression testing.

This article describes ironmaking and steelmaking practices (melt or liquid processing, including hot metal desulfurization) and discusses the evolution of these processes and their effects on steel properties. The physical chemistry of steelmaking may appear deceptively simple for integrated steel mill operations where ore from the ground is converted into steel. The various refining steps that occur in steelmaking are reviewed. The article also describes solid processing of steel, with emphasis on hot and cold rolling, thermomechanical processing, and annealing of flat steel products.

This article describes the most commonly used test methods for determining flow stress in metal-forming processes. The methods include tension, ring, uniform compression, plane-strain compression, torsion, split-Hopkinson bar, and indentation tests. The article discusses the effect of deformation heating on flow stress. It provides metallurgical considerations at hot working temperatures and presents flow curves at conventional metalworking strain rates. The article describes the effect of microstructural scale, crystallographic texture, and equiaxed phases on flow stress at hot working temperatures. It tabulates a summary of certain values describing the flow stress-strain rate relation for steels, aluminum alloys, copper alloys, titanium alloys, and other metals at various temperatures.

This article provides a brief historical perspective, a classification of metallurgical processes, basic model development efforts, and an overview of the potential future directions for the modeling of metals processing. It describes the classification of material behavior models, which can be grouped broadly into three classes: statistical, phenomenological, and mechanistic models. The article also presents an overview of the potential directions for the modeling of metals processing.

The misorientation of a boundary of a growing grain is defined not only by its crystallography but also by the crystallography of the grain into which it is growing. This article focuses on the Monte Carlo Potts model that is typically used to model grain growth, Zener-Smith pinning, abnormal grain growth, and recrystallization. It introduces the basics of the model, providing details of the dynamics, simulation variables, boundary energy, boundary mobility, pinning systems, and stored energy. The article explains how to incorporate experimental parameters and how to validate the model by comparing the observed behavior quantitatively with theory. The industrial applications of the model are also discussed. The article also provides a wide selection of the algorithms for implementing the Potts model, such as boundary-site models, n -fold way models, and parallel models, which are needed to simulate large-scale industrial applications.