This article provides an overview of heat treatment processes, namely, solution heat treatment, quenching, natural aging, and artificial aging. It contains a table that lists the various heat treatment tempers commonly practiced for nonferrous castings. The article describes microstructural changes that occur due to the heat treatment of cast alloys.

The choice of heat treatment depends on the service requirements of a given bearing and how the bearing will be made. This article describes the design parameters, material characteristics required to sustain performance characteristics, metallurgical properties, and dimensional stability. It also provides a description of various extensively-used heat treatment processes, namely, carburizing, carbonitriding, induction surface hardening, and nitriding associated with various bearings. In addition, the article explores the factors to be considered in selecting a process and explains why it is optimum for a specific application.

This article presents an overview of the techniques used in the design for heat treatment and discusses the primary criteria for design: minimization of distortion and undesirable residual stresses. It provides theoretical and empirical guidelines to understand the sources of common heat treat defects. A simple example is presented to demonstrate how thermal and phase-transformation-induced strains cause dimensional changes and residual stresses. The article concludes with a discussion on the heat treatment process modeling technology.

This article provides an overview of surface contaminants that may affect the heat treatment processes and end-product quality. It presents information on the chemicals used to clean different surface contaminants of steels. The article discusses three types of cleaning methods, namely, mechanical, chemical, and electrochemical and their effectiveness and applicability. The mechanical cleaning methods include grinding, brushing, steam or flame jet cleaning, abrasive blasting, and tumbling. Solvent cleaning, emulsion cleaning, alkaline cleaning, acid cleaning, pickling, and descaling are chemical cleaning methods. The electrochemical cleaning methods include electropolishing, electrolytic alkaline cleaning, and electrolytic pickling. The article provides information on cleanliness measurement methods such as qualitative tests and quantitative tests to ensure product quality. Health hazards that may be associated with each cleaning method and the general control measures to be used for each hazard are tabulated.

The heat treatment of steel is based on the physical metallurgical principles that relate to its processing, properties, and structure. The microstructures that result from the heat treatment of steel are composed of one or more phases in which the atoms of iron, carbon, and other elements in steel are associated. This article describes the phases of heat treated steel, and provides information on effect of temperature change and the size of carbon atoms relative to that of iron atoms during the heat treatment.