This chapter presents the composition, microstructure, processing, deformation mechanism, mechanical properties, formability, and attributes of transformation-induced plasticity 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.

Alloy steels are alloys of iron with the addition of carbon and one or more of the following elements: manganese, chromium, nickel, molybdenum, niobium, titanium, tungsten, cobalt, copper, vanadium, silicon, aluminum, and boron. Alloy steels exhibit superior mechanical properties compared to plain carbonsteels as a result of alloying additions. This chapter describes the beneficial effects of these alloying elements in steels. It discusses the mechanical properties, nominal compositions, advantages, and engineering applications of various classes of alloy steels. They are low-alloy structural steels, SAE/AISI alloy steels, high-fracture-toughness steels, maraging steels, austenitic manganese steels, high-strength low-alloy steels, dual-phase steels, and transformation-induced plasticity steels.

This chapter discusses the properties and behaviors of advanced high-strength steels used in the automotive industry, including dual- and complex-phase steels, transformation-induced plasticity steels, ferritic-bainitic steels, and quenched and partitioned steels. It explains how different manufacturing processes, including coating, affect the grain size, microstructure, and formability of these important steels.

This chapter discusses various alloying and processing approaches to increase the strength of low-carbon steels. It describes hot-rolled low-carbon steels, cold-rolled and annealed low-carbon steels, interstitial-free or ultra-low carbon steels, high-strength, low-alloy (HSLA) steels, dual-phase (DP) steels, transformation-induced plasticity (TRIP) steels, and martensitic low-carbon steels. It also discusses twinning-induced plasticity (TWIP) steels along with quenched and partitioned (Q&P) steels.

Martensitic (MS) steel is produced by quenching carbon steel from the austenitic phase into martensite. This chapter presents the compositions, microstructures, processing, deformation mechanism, mechanical properties, hot forming process, and attributes of MS steels.

This chapter presents the nomenclature, generations, thermomechanical processing, microstructure development, and mechanical properties of advanced high-strength steels.