This appendix contains figures that illustrate specimen orientation and crack plane codes for rolled plate, drawn bars, and hollow cylinders.

This chapter explains that the key to forging is understanding and controlling metal flow and influential factors such as tool geometry, the mechanics of interface friction, material characteristics, and thermal conditions in the deformation zone. It also reviews common forging processes, including closed-die forging, extrusion, electrical upsetting, radial forging, hobbing, isothermal forging, open-die forging, orbital forging, and coining.

The vast majority of beryllium products are manufactured from blocks, forms, or billets of compacted powder that are machined or worked into shape. This chapter describes the metalworking processes used, including rolling, forming, forging, extrusion, drawing, and spinning. It covers the qualitative and quantitative aspects of each process and provides examples showing how they are implemented and the results that can be achieved. The chapter also discusses the issue of beryllium’s low formability and describes some of the advancements that have been made in near-net shape processing.

Forged aluminum products vary widely in their production methods and applications. The forging process allows for control of microstructure and directional properties, and their fatigue and fracture resistance are superior to shape castings. This chapter presents the types, equipment, process steps, alloys, and products of aluminum forging.

This chapter discusses bulk deformation processes and how they are used to reshape metals and refine solidification structures. It begins by describing the differences between hot and cold working along with their respective advantages. It then discusses various forging methods, including open-die and closed-die forging, hot upset and roll forging, high-energy-rate forging, ring rolling, rotary swaging, radial and orbital forging, isothermal and hot-die forging, precision forging, and cold forging. The chapter also includes information on cold and hot extrusion and drawing operations.

This chapter discusses the effect of friction and lubrication on forgings and forging operations. The discussion covers lubrication mechanisms, the use of friction laws, tooling and process parameters, and the lubrication requirements of specific materials and forging processes. The chapter also describes several test methods for evaluating lubricants and explains how to interpret associated test data.

This chapter describes the processes involved in the fabrication of wrought and cast metal products. It discusses deformation processes including bending and forming, material removal processes such as milling, cutting, and grinding, and joining methods including welding, soldering, and brazing. It also discusses powder consolidation, rolling, drawing and extrusion, and common forging methods.

Forging is a deformation process achieved through the application of compressive stresses. During the stroke, pressures and velocities are continuously changing and the initial lubricant supply must suffice for the duration of the operation. Lubricant residues and pickup products also change with time, further complicating the analysis of friction and wear. This chapter provides a qualitative and quantitative overview of the mechanics and tribology of forging in all of its forms. It discusses the effects of friction, pressures, forces, and temperature on the deformation and flow of metals in open-die, closed-die, and impression-die forging and in back extrusion and piercing operations. It presents various ways to achieve fluid-film lubrication in upset forging processes and examines the cause of barreling, defect formation, and folding in the upsetting of cylinders, rings, and slabs. It also explains how to evaluate lubricants, friction, and wear under hot, cold, and warm forging conditions and how to extend die life and reduce defects when processing different materials.

This article presents six case studies of failures with steel forgings. The case studies covered are crankshaft underfill; tube bending; spade bit; trim tear; upset forging; and avoidance of flow through, lap, and crack. The case studies illustrate difficulties encountered in either cold forging or hot forging in terms of preforge factors and/or discontinuities generated by the forging process. Supporting topics that are discussed in the case studies include validity checks for buster and blocker design, lubrication and wear, mechanical surface phenomenon, forging process design, and forging tolerances. Wear, plastic deformation processes, and laws of friction are introduced as a group of subjects that have been considered in the case studies.

This chapter discusses the effects of hot working on the structure and properties of steel. It explains how working steels at high temperatures promotes diffusion, which helps close cavities and pores, and how it changes the shape and distribution of segregates, offsetting their effect. It describes the effect of hot working on nonmetallic inclusions and the many properties influenced by them. It discusses the recrystallization mechanism by which hot working produces microstructural changes and explains how to control it by adjusting temperature, degree of reduction, and cooling rates. It describes special cases of segregation, including banding and why it occurs, and the application of closed die forging. The chapter also presents several examples of hot working defects, including forging laps, cracks, and overheated or burned steel.

There are numerous approximate methods, both analytical and numerical, for analyzing forging processes. None are perfect because of the assumptions made to simplify the mathematical approach, but all have merit. This chapter discusses the slab, upperbound, and finite element methods, covering basic principles, implementation, and advantages and disadvantages in various applications.

In forgings of both ferrous and nonferrous metals, the flaws that most often occur are caused by conditions that exist in the ingot, by subsequent hot working of the ingot or the billet, and by hot or cold working during forging. The inspection methods most commonly used to detect these flaws include visual, magnetic particle, liquid penetrant, ultrasonic, eddy current, and radiographic inspection. This chapter provides a detailed discussion on the characteristics, process steps, applications, advantages, and limitations of these methods. It also describes the flaws caused by the forging operation and the principal factors that influence the selection of a nondestructive inspection method for forgings.

This chapter discusses the equipment and processes used to convert titanium billet and bar into useful shapes or more refined product forms. These secondary working operations include open-die, closed-die, hot-die and isothermal forging as well as ring rolling and extruding. The chapter describes each method in detail and how it affects the microstructure and mechanical properties of various titanium alloys. It also discusses the propensity of titanium to react with oxygen and hydrogen when heated and explains how to mitigate the effects.

This chapter discusses the use of finite-element methods for modeling cold forging processes. The discussion covers process modeling inputs, such as geometric parameters, material properties, and interface conditions, and includes several application examples.