This article provides useful information on the selection of steels for heat treatment in order to achieve the required hardness. It discusses the effects of alloying elements on hardenability using the Grossmann's concept, and presents a discussion on the effects of alloying elements in hot-worked and cold-drawn steels. The article focuses on the selection of carbon and alloy steels based on the function of the alloying elements, and discusses the specific effects of alloying elements in steel in a tabulated form. The depth and degree of hardening (percentage of martensite) are dictated by the engineering stress analysis. Mechanical properties of quenched and tempered steels develop similar tensile properties for all practical purposes for all compositions with the same hardness. The article also provides information on the selection of steels to meet the required hardness, and elucidates the concept of hardenability for wear resistance with the help of graphs.

This article provides a detailed discussion on the factors involved in the selection of steels for austempering, including section thickness limitations of steel parts and modifications of austempering practice. The selection of steel for an austempered component is based on the processing characteristics of the heat treating equipment employed. It is also based on the hardenability and transformation characteristics of the steel alloy as indicated by time-temperature-transformation and isothermal-transformation diagrams. The article contains tables that compare the dimensional changes that occur in stabilizer bars as a result of oil quenching and tempering with those that resulted from austempering. It also discusses the production applications of austempering and the problems encountered in austempering together with their solutions.

This article provides an overview of the different classification and designation systems of wrought carbon steel and alloy steel product forms with total alloying element contents not exceeding 5″. It lists the quality descriptors, chemical compositions, cast or heat composition ranges, and product analysis tolerances of carbon and alloy steels. The major designation systems discussed include the Society of Automotive Engineers (SAE)-American Iron and Steel Institute (AISI) designations, Unified Numbering System (UNS) designations, American Society for Testing and Materials (ASTM) designations, Aerospace Material Specification (AMS), and other international designations and specifications.

This article addresses classifications and designations for carbon steels and low-alloy steels, particularly high-strength low-alloy (HSLA) steels, based on chemical composition, manufacturing methods, finishing method, product form, deoxidation practice, microstructure, required strength level, heat treatment and quality descriptors. It describes the effects of alloying elements on the properties and characteristics of steels. The article provides extensive tabular data pertaining to domestic and international designations of steels.

This article addresses classifications and designations for carbon and low-alloy steel sheet and strip product forms based on composition, quality descriptors, mechanical properties, and other factors. Carbon steel sheet and strip are available as hot-rolled and as cold-rolled products. Low-alloy steel sheet and strip are used primarily for applications that require the mechanical properties normally obtained by heat treatment. The descriptors of quality used for hot-rolled plain carbon steel sheet and strip and cold-rolled plain carbon steel sheet include structural quality, commercial quality, drawing quality, and drawing quality, special killed. The surface texture of low-carbon cold-rolled steel sheet and strip can be varied between rather wide limits. The modified low-carbon steel grades discussed in the article are designed to provide sheet and strip products having increased strength, formability, and/or corrosion resistance. The article also summarizes the key operations involved in the three alternative direct casting processes: thin slab, thin strip, and spray casting.

This article discusses different types of mechanical fasteners, including threaded fasteners, rivets, blind fasteners, pin fasteners, special-purpose fasteners, and fasteners used with composite materials. It describes the origins and causes of fastener failures and with illustrative examples. Fatigue fracture in threaded fasteners and fretting in bolted machine parts are also discussed. The article provides a description of the different types of corrosion, such as atmospheric corrosion and liquid-immersion corrosion, in threaded fasteners. It also provides information on stress-corrosion cracking, hydrogen embrittlement, and liquid-metal embrittlement of bolts and nuts. The article explains the most commonly used protective metal coatings for ferrous metal fasteners. Zinc, cadmium, and aluminum are commonly used for such coatings. The article also illustrates the performance of the fasteners at elevated temperatures and concludes with a discussion on fastener failures in composites.

This article first provides an overview of the types of mechanical fasteners. This is followed by sections providing information on fastener quality and counterfeit fasteners, as well as fastener loads. Then, the article discusses common causes of fastener failures, namely environmental effects, manufacturing discrepancies, improper use, or incorrect installation. Next, it describes fastener failure origins and fretting. Types of corrosion in threaded fasteners and their preventive measures are then covered. The performance of fasteners at elevated temperatures is addressed. Further, the article discusses the types of rivet, blind fastener, and pin fastener failures. Finally, it provides information on the mechanism of fastener failures in composites.

This article provides an overview of common quenching media, the factors involved in the mechanism of quenching, and process variables, namely, surface condition, mass and section size of the workpiece, and flow rate of the quenching liquid. It describes the methods of quenchant characterization using hardening-power and cooling-power tests. The article discusses the fundamentals involved in heat-transfer coefficient and heat flux of quenching processes. This discussion is followed by various actual examples of applications of these methods using simplified equations. Quenchant evaluation, classification, selection, and maintenance are reviewed in detail. The article addresses the various reasons for quench oil variability and complications due to aging and contamination.