This article discusses the properties of threaded fasteners made from carbon and low-alloy steels containing a maximum of 0.55% carbon. It provides guidelines for the selection of steels for bolts, studs, and nuts intended for use at temperatures between -50 and 370 deg C. The article also discusses steels rated for service above 370 deg C and describes internationally recognized grade designations. The specifications provided can be used to outline fastener requirements, control manufacturing processes, and establish functional or performance standards. The most commonly used protective metal coatings for ferrous metal fasteners; zinc, cadmium, and aluminum; are described as well.

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.

Porcelain enamels are glass coatings applied primarily to products or parts made of sheet steel, cast iron, and aluminum to improve appearance and to protect the metal surface. This article describes the types of porcelain enamels, and details enamel frits for these materials. It provides a list of steels suitable for porcelain enameling and discusses the most important factors considered in the selection of steel for porcelain enameling. The article briefly presents the preparation methods of these materials for porcelain enameling and covers the methods, and furnaces of porcelain enameling. It examines the role of coating thickness, firing time and temperature, metal substrate, and color on the performance of enameled surfaces. The article concludes with a discussion on the properties of enameled surfaces, factors considered in process control, and test procedures for evaluating the quality of enameled surfaces.

The selection of materials for welded construction applications involves a number of considerations, including design codes and specifications. Mobile structures have quite different materials requirements for weight, durability, and safety than stationary structures, which are built to last for many years. This article provides an overview of the service conditions. It offers guidance for material selection applications, including bridges and buildings, pressure vessels and piping, shipbuilding and offshore structures, aerospace systems, machinery and equipment, automobiles, railroad systems, and sheet metal. Material properties and welding processes that may be significant in meeting design goals are also described.

Cold-finished steel bars are carbon and alloy steel bar products (round, square, hexagonal, flat, or special shapes) that are produced by cold finishing previous hot-wrought bars. by means of cold drawing, cold forming, turning, grinding, or polishing (singly or in combination) to yield straight lengths or coils that are uniform throughout their length. Cold-finished bars fall into five classifications: cold-drawn bars; turned and polished bars; cold-drawn, ground, and polished bars; turned, ground, and polished bars; cold-drawn, turned, ground, and polished bars. Different size tolerances are applicable to cold-finished products, depending on shape, carbon content, and heat treatment. When used to identify cold-finished steel bars, the various quality descriptors are indicative of many characteristics, such as degree of internal soundness, relative uniformity of chemical composition, and relative freedom from detrimental surface imperfections. Cold drawing significantly increases machinability, tensile and yield strengths of steel bars. Two special die-drawing processes have been developed to give improved properties over those offered by standard drawing practices. These processes are cold drawing using heavier-than-normal drafts, followed by stress relieving; and drawing at elevated temperatures.

Quenching and partitioning (Q&P) steel is a term used to describe a series of C-Si-Mn, C-Si-Mn-Al, or other steels subjected to the quenching and partitioning heat treatment process. This article discusses the Q&P steel's chemical compositions and mechanical properties, and provides an overview of the important background and product characteristics with a focus on the automotive sheet steel application. It schematically represents the continuous annealing process, consequent phase-transformation behaviors, and forming-limit curves of Q&P steels. The article describes the parameters associated with resistance spot welding, laser welding, and metal active gas welding. It also provides useful information of retained austenite volume fraction measured by x-ray diffraction and electron backscatter diffraction. The article also examines microstructure evolution during tensile testing at different strain levels using electron backscatter diffraction.

Quenching is one of the most important heat treating processes, because it is so closely related to dimensional control requirements and control of residual stresses. 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.

Metallic alloys that are typically used for medical purposes include stainless steels, Ti-6Al-4V, and Co-Cr-Mo. This article discusses the relative merits of each of these alloys. The utilization of stainless steels in the biomedical industry, especially in relation to the additive manufacturing (AM) process, is the main focus of this article. The characteristics of various stainless steels are described subsequently, and the categories that are of relevance to the biomedical industry are identified. The types of stainless steels covered are austenitic, ferritic, martensitic, duplex, and precipitation-hardened stainless steels. The article discusses the potential benefits of AM for biomedical devices. It describes the types of AM processes for stainless steels, namely binder jet, directed-energy deposition, and laser powder-bed fusion. The article reviews the AM of austenitic, martensitic, and PH stainless steels for biomedical applications. In addition, the challenges and obstacles to the clinical use of AM parts are covered.

This article discusses tubular products made from wrought carbon or alloy constructional steels, particularly pipe, specialty tubing, and oil country tubular goods. The article covers product classifications, available specifications, chemical compositions, sizes, and other dimensional attributes. Some of the common types of pipe are standard pipe, conduit pipe, piling pipe, pipe for nipples, transmission or line pipe, water main and water well pipe, and pressure pipe. Pipe in suitable sizes and most products classified as tubing, both seamless and welded, may be cold finished. Pressure tubes, a separate classification, include double-wall brazed tubing, structural tubing, welded mechanical tubing, continuous-welded cold-finished mechanical tubing, and seamless mechanical tubing.

Maintenance coating is an important part of any meaningful asset-preservation strategy in facilities producing pulp and paper and other chemicals. This article discusses maintenance coating for carbon steel structures and process equipment exposed to normal external pulp and paper mill atmospheric conditions. The important requirements and standards for surface preparation are emphasized and common issues encountered in maintenance coating projects are described.

This article characterizes the physical differences between powder metallurgy (PM) and wrought or cast materials, as they apply to joining. It discusses acceptable joining procedures and techniques, including welding and brazing and solid-state methods. Information on the weldability of various PM materials is presented. The article also describes the effects of porosity on several important properties that affect the welding characteristics.

Low-temperature surface hardening is mostly applied to austenitic stainless steels when a combination of excellent corrosion performance and wear performance is required. This article provides a brief history of low-temperature surface hardening of stainless steel, followed by a discussion on physical metallurgy, including crystallographic identity, thermal stability and decomposition, nitrogen and carbon solubility in expanded austenite, and diffusion kinetics of interstitials. It provides a description of low-temperature nitriding and nitrocarburizing processes for primarily austenitic and, to a lesser extent, other types of stainless steels along with practical examples and industrial applications of these steels.

This article contains a table that presents information on cross-references to standard SAE carbon and low-alloy steel grades to selected chemically similar steels.

This article is a compilation of tables that present information on cross-referencing of steel designations that are followed in France, Germany, Italy, Japan, Sweden, and Britain to AISI/SAE.

Hardness conversions are empirical relationships that are defined by conversion tables limited to specific categories of materials. This article is a comprehensive collection of tables that list hardness conversion formulas. Approximate Rockwell B and C hardness conversion numbers for nonaustenitic steels, and approximate equivalent hardness numbers for Brinell and Vickers (diamond pyramid) hardness numbers for steels are provided.

This article provides an overview of steel gear heat treating processes and brings out the nuances of the various important heat treating considerations for steel gear applications. The heat treatment processes covered are annealing, carburizing, hardening, low-pressure carburizing, induction hardening, through hardening, and nitriding. In view of the emerging use of mathematical modeling and optimization, a brief overview of its application for process and design optimization is also provided.

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 presents an overview of common heat treating problems arising due to poor part design, material incapabilities, difficult engineering requirements, incorrect heat treatment practice, and nonuniform quenching with emphasis on distortion and cracking of quenched and tempered steels. It provides useful information on selection of steels for heat treatment, and discusses the causes of residual stresses, distortion (size and shape), and size changes due to hardening and tempering. The article elucidates the control techniques for such distortions. It describes the importance of decarburizing, and discusses the problems caused by heating, cracking, quenching, typical steel grades, and design.

Successful hardening depends on the hardenability of steel composition, the geometry of parts, the quenching system, and on the heat treating process used. This article provides a brief overview of the computation and use of quench factor analysis (QFA) to quantify as-quenched hardness for carbon and low-alloy steels. As a single-value parameter alternative to Grossmann H-values, QFA is a potential method to qualify a quenching medium or process or to effectively monitor variation of quench severity due to either the quenchant or the system. The article describes the procedures for experimentally determining the quench factors by using a type 304 austenitic stainless steel probe. Typical examples of the utilization of QFA for quenchant characterization are provided. The article also describes the methods for experimentally generating time-temperature-property curves.

This article focuses on the mechanisms, models, prevention, correction, and effects associated with decarburization inherited from semi-finished product processing prior to induction heating. It discusses the diffusion of carbon in austenitic iron, which has a face-centered cubic crystal structure that provides an interstitial path for the migration of the relatively small carbon atoms. The article describes the evolution of steel microstructure with progressive decarburization (in air) to a steady-state carbon gradient using an iron-iron carbide phase diagram. It provides useful information on the impact of alloying on vulnerability to decarburization, and the impact of decarburization on the mechanical properties of steels and cast irons. The article also describes the technological operations that potentially cause decarburization and the practical implications for induction hardening.