Work or strain hardening is a natural consequence of most working and forming operations on aluminum and its alloys. This article describes the annealing practices of strain-hardened alloys. It lists the temper designations for strain-hardened alloys. The article discusses the annealing of worked structures in terms of recovery, recrystallization, and grain coarsening. It summarizes some of the annealing treatments used in conjunction with fabrication by metal working, including preheating, interannealing, self-annealing, stabilization, and stoving. The article concludes with information on the key process parameters affecting the final properties of aluminum alloys.

Annealing is an essential treatment in the fabrication of metal parts and semiproducts. This article discusses the processes involved in annealing, namely, recovery, recrystallization, and grain coarsening. It lists the heat treatment conditions of processed aluminum alloys. It provides information on the types of heat treatment, which include preheating, full anneal, stabilization, and stoving. The article describes the steps involved for achieving the age-hardening effect and the strongest hardening effect in aluminum. The steps to increase the strength of aluminum alloys by extremely fine, dispersed second-phase particles are: solution heat treatment, quenching, and age hardening. Finally, the article also discusses the process parameters of annealing, including the effect of strain, effect of temperature, effect of heating rate, and the effect of alloy elements, and the effect of annealing on anisotropy.

Solid-state transformations occurring in a weld are highly nonequilibrium in nature and differ distinctly from those experienced during casting, thermomechanical processing, and heat treatment. This article focuses on welding metallurgy of fusion welding of steels and highlights the fundamental principles that form the basis of many of the developments in steels and consumables for welding. Examples in the article are largely drawn from the well-known and relatively well-studied case of ferritic steel weldments to illustrate the special physical metallurgical considerations brought about by the weld thermal cycles and by the welding environment. The article provides information on welds in other alloy systems such as stainless steels and aluminum-base, nickel-base, and titanium-base alloys.

Solid-state transformations occurring in a weld are highly nonequilibrium in nature and differ distinctly from those experienced during casting, thermomechanical processing, and heat treatment. This article provides a description of the special factors affecting transformation behavior in a weldment. It reviews the heat-affected and fusion zones of single-pass and multi-pass weldments. The article also includes a discussion on the welds in alloy systems, such as stainless steels and aluminum-base, nickel-base, and titanium-base alloys.

Austenitization refers to heating into the austenite phase field, during which the austenite structure is formed. This article highlights the purpose of austenitization, and reviews the mechanism and importance of thermodynamics and kinetics of austenite structure using an iron-carbon binary phase diagram. It also describes the effects of austenite grain size, and provides useful information on controlling the austenite grain size using the thermomechanical process.

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.