This chapter discusses the factors that influence the load-deformation relationship at the heart of most metal forming operations. It describes the changes that occur in tensile test samples and the various ways test data can be plotted and analyzed, particularly for design purposes. It discusses the effect of normal and planar anisotropy, the development and use of flow stress curves, and how formability is usually measured and expressed. It explains how formability measurements serve as a guide for process and tool design engineers as well as others. It also discusses the development and use of forming limit curves and the extensive amount of information they provide.

Sheet metal forming operations consist of a large family of processes, ranging from simple bending to stamping and deep drawing of complex shapes. Because sheet forming operations are so diverse in type, extent, and rate, no single test provides an accurate indication of the formability of a material in all situations. However, as discussed in this chapter, the uniaxial tensile test is one of the most widely used tests for determining sheet metal formability. This chapter describes the effect of material properties and temperature on sheet metal formability. Information on the types of formability tests is also provided. The chapter discusses the processes involved in uniaxial and plane-strain tensile testing. Examples include the uniaxial tensile test and the plane-strain tensile test which are subsequently described.

This chapter describes the formability and forming characteristics of low-carbon sheet steels, coated sheet steels, stainless steels, and aluminum and magnesium alloys. It provides property data as well as flow stress curves for numerous grades of each material and explains how composition, microstructure, and processing methods influence forming behaviors.

This chapter is a brief account of the composition, microstructures, heat treatment, deformation mechanisms, mechanical properties, formability, and special attributes of austenitic stainless steels.

Transformation-induced plasticity (TRIP) steels are characterized by their excellent strength and high ductility, which allow the production of more complicated parts for lightweight automotive applications. This chapter provides an overview of the compositions, microstructures, processing, deformation mechanism, mechanical properties, hot forming, tempering, and special attributes of TRIP the steels.

This chapter summarizes the performance attributes of advanced high-strength steels, namely stiffness, strength, strain hardening, fatigue, crashworthiness, formability, toughness, and bake hardening.

Tube hydroforming is a material-forming process that uses pressurized fluid to plastically deform tubular materials into desired shapes. It is widely used in the automotive industry for making exhaust manifolds, catalytic converters, shock absorber housings, and other parts. This chapter discusses the basic methods of tube hydroforming and the underlying process mechanics. It explains how to determine if a material is a viable candidate and whether it can withstand preforming or bending operations. It describes critical process parameters, such as interface pressure, surface expansion and contraction, and sliding velocity, and how they influence friction, lubrication, and wear. The chapter also provides information on forming presses and tooling, tube hydropiercing, and the use of finite elements to determine optimal processing conditions and loading paths.

This chapter describes the effect of temperature and strain rate on the mechanical properties and forming characteristics of aluminum and magnesium sheet materials. It discusses the key differences between isothermal and nonisothermal warm forming processes, the factors that affect heat transfer, die heating techniques, and press systems. It also discusses the effect of forming temperature, punch velocity, blank size, and other parameters on deep drawing processes, making use of both experimental and simulated data.

This chapter covers the mechanics and tribology of sheet metalworking processes, including shearing, bending, spinning, stretching, deep drawing, ironing, and hydroforming. It explains how to determine friction, wear, and lubrication needs based on process forces, temperatures, and strains and the effects of strain hardening on workpiece materials. It presents test methods for evaluating process tribology, describes lubrication and wear control approaches, and discusses the factors, such as surface roughness, lubricant breakdown, and adhesion, that can lead to galling and other forms of wear. It also provides best practices for selecting, evaluating, and applying lubricants for specific materials, including steels, stainless steels, and aluminum and magnesium alloys.

Martensitic steels are produced by quenching carbon steel from the austenite phase into martensite. This chapter provides information on the composition, microstructures, processing, deformation mechanisms, mechanical properties, hot forming, tempering, and special attributes of martensitic steels.