This chapter, a detailed account of furnaces and related equipment for heat treating, begins by describing three basic modes of heat transmission, namely conduction, convection, and radiation, followed by a discussion on the working principle, applications, advantages, and disadvantages of furnaces classified based on the heat transfer medium employed. The types of furnaces covered are batch-type, continuous-type, liquid bath, fluidized bed, and vacuum. The subsequent sections provide information on furnace parts, fixtures, quenching mediums, and quenching systems. The final section of the chapter describes the types of atmospheres available, emphasizing their applications and limitations.

After pouring, castings are allowed to solidify and cool. They are later removed from the molds in the shakeout operation. A series of activities then follow, which are generally referred to as finishing and heat treatment. These activities can be broadly categorized as shakeout, abrasive blast cleaning, removal of risers, ingates, and discontinuities, rough inspection, removal of discontinuities, finishing welding, heat treatment, and final visual, dimensional, and NDT inspection. This chapter provides a detailed discussion on these activities.

This chapter discusses the types, methods, and advantages of heat treating procedures, including annealing, normalizing, tempering, and case hardening. It describes the iron-carbon system, the formation of equilibrium and metastable phases, and the effect of alloy elements on hardenability and tempering response. It discusses the significance of critical temperatures, the use of transformation diagrams, and types of annealing treatments. It also provides information on heat treating furnaces, the effect of heating rate on transformation temperatures, quench and temper procedures, and the use of cold treating.

This chapter describes the general characteristics of major types of steel annealing, including the process of normalization, which is a process that refines or normalizes the microstructure of steel. The first part of the chapter begins with an overview of the three-stage process of recovery, recrystallization, and grain growth. This is followed by discussions on annealing processes, namely subcritical annealing, critical-range annealing, full annealing, isothermal annealing, annealing for microstructure, and solution or quench annealing. Next, the chapter describes two undesirable reactions that occur during annealing: decarburization and scaling. Information on the gases and gas mixtures used for controlled atmospheres is then provided. The second part of the chapter focuses on the processes involved in normalizing, along with information on furnace equipment for normalizing. In addition, the chapter includes information on processes involved in induction heating of steel.

The machinery and equipment required for rod and tube extrusion is determined by the specific extrusion process. This chapter provides a detailed description of the design requirements and principles of machinery and equipment for direct and indirect hot extrusion. It then covers the presses and auxiliary equipment for tube extrusion, induction furnaces for billet processing, handling systems for copper and aluminum alloy products, extrusion cooling systems, and age-hardening ovens. Next, the chapter describes the principles and applications of equipment for the production of aluminum and copper billets. Then, it focuses on process control in both direct and indirect hot extrusion of aluminum alloys without lubrication. The chapter describes the technology of electrical and electronic controls in the extrusion process. It ends with a discussion on the factors that influence the productivity and quality of the products in the extrusion process and methods for process optimization.

This chapter provides information on the properties and behaviors of stainless steels and stainless steel powders. It begins with a review of alloy designation systems and grades by which stainless steels are defined. It then describes the composition, metallurgy, and engineering characteristics of austenitic, ferritic, martensitic, duplex, and precipitation hardening stainless steel powders and metal injection molding grades.

Gas (atmosphere) carburizing is the de facto standard by which all other surface hardening techniques are measured and is the emphasis of this chapter. Initially, the chapter describes the process and equipment for gas carburizing. This is followed by sections discussing the processes involved in quenching, hardening, tempering, recarburizing, and cold treatment of carburized and quenched gears. Next, the chapter reviews the selection process of materials for carburized gears and provides information on carbon content, properties, and core hardness of gear teeth. The problems associated with carburizing are then covered, followed by the processes involved in heat treat distortion and shot peening of carburized and hardened gears. Information on grinding stock allowance on tooth flanks to compensate for distortion is also provided. The chapter further discusses the applications of carburized and hardened gears. Finally, it reviews vacuum carburizing and compares the attributes of conventional gas carburizing and vacuum carburizing.