Coverage on heat treating in the ASM Handbook series is being expanded into several volumes, and ASM Handbook, Volume 4A,Steel Heat Treating Fundamentals and Processesis the first of multiple volumes on heat treating. Volume 4A interoduces the basics of steel heat treating and provides in-depth coverage of the many steel heat treating processes. Coverage includes:Physical metallurgy of steel heat treatmentFundamentals of steel hardness and hardenabilityPractical aspects of hardenability as a key criterion in the selection of steelHardenability calculations and the use of hardenability dataFundamentals and practical aspects of steel quenchingExpanded coverage on quenching processesUpdates and expansion on annealing, tempering, austempering and martemperingNew articles on cleaning, subcritical annealing, austenitizing, and quench partitioning of steel heat treatmentSignificant expansion on the fundamental and applied aspects of surface hardening by applied energy, carburizing, carbonitriding, nitriding, and diffusion coatings.