Preface

Quenching is one of the most important processes involved in a successful heat treatment. Not only is the quenchant selection critical, but equally so is the quenchant process itself. A successful quenching process is of vital importance in achieving the target hardness in microstructure of the workpiece, but equally, if not more importantly, is doing so while minimizing undesirable distortion and excessive residual stresses.

The Handbook of Quenchants and Quenching Technology, co-edited by G.E. Totten, C.E. Bates, and N.A. Clinton, was first published by ASM International in 1993. The book successfully provided a well-referenced, broad overview of quenching media in general use internationally at the time and also integrated factors involved in successful design of the quenching process. Although the book continues to enjoy broad use as an authoritative general text, there has been an enormous amount of new insightful information published over the intervening 30 years since it was originally published. This book, ASM Handbook, Volume 4F: Quenchants and Quenching Technology, was developed as a well-referenced major handbook to address these increasingly important gaps in the original 1993 text on this topic.

Volume 4F addresses quenchant selection, quenchant use, and quenching technology (process and design); these topic areas are addressed in four divisions and 24 rigorous, well-referenced articles, including:

Metallurgical Fundamentals of Quenching: A general understanding of the impact of the chemical composition, metallurgical transformations, and their general microstructures is provided. The development and use of phase diagrams is also described.

Hardenability of Steels and Cast Irons: A thorough understanding of the ability to harden (hardenability) iron and steel compositions is necessary in the appropriate selection of various quenchants and quench processes.

Heat Transfer during Quenching Processes: Quenchants are essentially heat-transfer agents. They are selected based on their general ability to control the cooling pathway necessary to achieve optimal physical and metallurgical properties while simultaneously achieving the minimal distortion and optimal residual stresses of the material being heat treated.

Cooling Curve Analysis: This article describes the electronic equipment, probe, thermocouples, data analysis software, and computational methodology necessary to conduct proper cooling curve analysis.

Acoustical Characterization: This quenchant characterization methodology provides useful complementary quench cooling characteristics to the more commonly used cooling curve analysis. Details of the acoustical characterization equipment and analysis process are also described.

Flow Visualization in Quenching: Flow visualization is an important characterization process to not only understand uniformity of the interfacial cooling mechanisms but also to characterize the overall impact of agitation on the uniformity of the overall cooling process.

Salt Solutions as Quenchants: This article describes situations necessitating the use of salt solutions as quenchants. It also provides an overview of various aqueous salt quenchants encountered and the impact of their selection and use on the overall cooling process.

Petroleum Oil Quenchants: This article discusses the differences between different oil quenching media (they are not all the same), their composition, cooling properties, selection, and use.

Polymer Quenchants: This article is an extensive overview of the more commonly encountered water-soluble polymers used in quenching applications, in addition to their different interfacial and bulk cooling behavior.

Vegetable and Animal Oil Quenchants: Although various vegetable and animal oils and their blends have fallen out of common use with the development and use of petroleum oil quenchants, they are now being used increasingly as an alternative quenchant in view of their relatively low environmental impact and toxicity properties; this is discussed in detail, in addition to vegetable oil composition and use.

Nanofluid Quench Media for Industrial Heat Treatment: This article contains various references to the use of nanofluids as steel quenchants. Their composition, preparation, and general use are also discussed.

Quench System Design: A detailed overview of various equipment options in process design is discussed in detail. Of particular importance is the use of computational methods to facilitate optimal design to ensure quench uniformity. An extensive overview of both equipment and design is also provided.

Agitator and Fluid Mixing Fundamentals for Quench Tank Applications: This article reviews options for propeller size, selection, and placement in various quench tank designs.

Advanced Industrial Quench System Design—Fluid Dynamics Analysis: This article details the use of computational fluid dynamics methodology in the design of an industrial quenching system, including model development, experimental validation, model simulations, and process design and optimization.

Martempering and Austempering: This article provides a detailed discussion of both the martempering and austempering processes and the similarity and differences between these processes. The discussion includes suitable steel compositions and hardenability, component part geometry, target design properties, mechanical handling, quenchant media selection, agitation, and bath temperatures.

Intensive Quenching Processes: A review of intensive quench system design and processing is provided, including numerical design criteria, steel selection, quenchants, and properties (especially optimal residual-stress profiles). A number of specific applications of intensive quenching are also provided.

Induction Quenching: One of the oldest methods of component heat treatment is induction heating and quenching; a thorough update on induction quenching and use is provided.

Spray Quenching: Spray quenching is an important alternative quenching process that includes both open and submerged sprays, in addition to the use of various quenching media. Details of the spray quenching process and its successful use are provided.

Gas Quenching Fundamentals: This article provides a detailed discussion of both the gas and gas mixtures involved and the different high-pressure equipment used. An overview of the gas quenching process is discussed, in addition to equipment and process safety.

Other Quenchants and Quenching Processes: Various important—but less frequently used—quenchants and quenching processes are discussed, including air, water, molten salt, fluidized beds, hot isostatic pressing quenching, ausbay quenching, ultrasonic quenching, and quenching in electric and magnetic fields. Newer quenching technologies, such as different computerized timed quenching processes, are also discussed.

Residual Stress: This article presents the theoretical background, formation mechanisms, tempering effects, and cryogenic cooling on residual-stress formation in quenched and case-hardened steels.

Quenching and Distortion: This article provides the basics of overall quench process distortion, the influence of quench distortion generation using numerous examples, and the potential for distortion compensation during the quenching process.

Industrial Applications of Analytics and Modeling for Carburizing and Quenching Processes: This article illustrates the use of process modeling and simulation through several relevant industrial case studies.

Steel Heat Treatment Failures due to Quenching: This article provides an overview of the fundamental material- and process-related parameters of quenching on residual stress, distortion control, and cracking. This overview is followed by various selected case histories of failures attributed to the quenching process.

Finally, the editors acknowledge that the production of this ASM Handbook with extensive coverage of quenchants and quench processes is the result of the outstanding expertise provided by the internationally renowned contributing authors. Without their outstanding contributions, this book would not have been possible.