Thermite welding (TW) is a fusion welding process in which two metals become bonded after being heated by superheated metal that has experienced an aluminothermic reaction. This article describes the thermite welding principles by presenting equations of the aluminothermic reaction that occurs in thermite welding. It provides information on the applications of thermite welding: rail welding, electrical connections, and railroad applications. The article concludes with a discussion on the associated safety aspects.

This article briefly reviews the analysis methods for spalling of striking tools with emphasis on field tests conducted by A.H. Burn and on the laboratory tests of H.O. McIntire and G.K. Manning and of J.W. Lodge. It focuses on the metallography and fractography of spalling. The macrostructure and microstructure of spall cavities are described, along with some aspects of the numerous specifications for striking/struck tools. The article also describes the availability of spall-resistant metals and the safety aspects of striking/struck tools in railway applications.

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.

Steel springs are made in many types, shapes, and sizes, ranging from delicate hairsprings for instrument meters to massive buffer springs for railroad equipment. The primary focus of this article is small steel springs that are cold wound from wire. Wire springs are of four types: compression springs (including die springs), extension springs, torsion springs, and wire forms. Chemical composition, mechanical properties, surface quality, availability, and cost are the principal factors to be considered in selecting steel for springs. Both carbon and alloy steels are used extensively. The three types of wire used in the greatest number of applications of cold formed springs are hard-drawn spring wire, oil tempered wire and music wire. Residual stresses can increase or decrease the strength of a spring material, depending on their direction. Steel springs are often electroplated with zinc or cadmium to protect them from corrosion and abrasion. Although some hot-wound springs are made of steels that are also used for cold-wound springs, hot-wound springs are usually much larger, which results in significant metallurgical differences. All spring design is based on Hooke’s law; charts and formulas are available to aid in the design of springs.

Hot-rolled steel bars and other hot-rolled steel shapes are produced from ingots, blooms, or billets converted from ingots or from strand cast blooms or billets and comprise a variety of sizes and cross sections. Most carbon steel and alloy steel hot-rolled bars and shapes contain surface imperfections with varying degrees of severity. Seams, laps, and slivers are probably the most common defects in hot-rolled bars and shapes. Another condition that could be considered a surface defect is decarburization. Hot-rolled steel bars and shapes can be produced to chemical composition ranges or limits, mechanical property requirements, or both. Hot-rolled carbon steel bars are produced to two primary quality levels: merchant quality and special quality. Merchant quality is the least restrictive descriptor for hot-rolled carbon steel bars. Special quality bars are employed when end use, method of fabrication, or subsequent processing treatment requires characteristics not available in merchant quality bars.

Because of the tough engineering environment of the railroad industry, fatigue is a primary mode of failure. The increased competitiveness in the industry has led to increased loads, reducing the safety factor with respect to fatigue life. Therefore, the existence of corrosion pitting and manufacturing defects has become more important. This article presents case histories that are intended as an overview of the unique types of failures encountered in the freight railroad industry. The discussion covers failures of axle journals, bearings, wheels, couplers, rails and rail welds, and track equipment.

Hadfield's austenitic manganese steel exhibits high toughness and ductility with high work-hardening capacity and, usually, good wear resistance. Beginning with an overview of the as-cast properties and composition of these class of steels, this article discusses the heat treatment methods used to improve their wear resistance, and the changes in the mechanical properties after heat treatment. Manganese steels are unequaled in their ability to work harden, exceeding even the metastable austenitic stainless steels in this feature.

This article discusses the processing, properties, and applications of various grades of lead and lead-base alloys with the aid of several tables and illustrations. It lists the Unified Numbering System (UNS) designations for various pure lead grades and lead-base alloys grouped according to nominal chemical composition. The properties of lead that make it useful in a wide variety of applications are also discussed. The largest usage of lead is in the lead acid storage batteries (in the grid plates, posts, and connector straps). Other applications include ammunition; cable sheathing; cast products such as type metals, terneplates, and foils; and building construction materials. Lead is also used as an alloying element in steel and in copper alloys to improve machinability and other characteristics. In many applications, lead is combined with stronger materials to make structures that have the best qualities of both materials such as the plumbum series.

This article first describes the two methods used in the 1998 U.S. corrosion cost study. In the first method, the cost was determined by summing the costs for corrosion control methods and contract services. In the second, the cost of corrosion was first determined for specific industry sectors and then extrapolated to calculate a national total corrosion cost. The article then reports the results and conclusions of the study. It concludes with information on corrosion prevention strategies.

This article provides a detailed discussion on the functions, applications, types, and selection criteria of exterior and interior rail coatings. It includes a discussion on the corrosivity, inspection/maintenance, and qualification of applicators/inspectors/facilities.

This datasheet provides information on key alloy metallurgy, and processing effects on physical and mechanical properties of extrusion alloy 6351.

This datasheet provides information on composition limits, product specifications, fabrication characteristics, processing effects on physical and mechanical properties, and applications of extrusion alloy 7003.

This article provides a background of friction-bearing failures due to overheating. The failures of locomotive axles caused by overheated traction-motor support bearings are discussed. The article also describes liquid-metal embrittlement (LME) in steel. It examines the results of various axle studies, with illustrations and concludes with information on the simulation of the LME mechanism.

This datasheet provides information on composition limits, heat treatment, processing effects on physical and mechanical properties, and applications of free-machining aluminum alloys 6033, 6040 and 6041.

Aluminum and its alloys are used in a broad range of applications. This article discusses the primary and secondary production of aluminum and the classification system for cast and wrought products. It describes some of the more common manufactured forms, including commercial wrought aluminum products, aluminum alloy engineered castings, powder metallurgy parts, and metal-matrix composites. The article also reviews fabrication characteristics such as machining, forming, forging, and joining. It concludes with a description of the major industrial applications of wrought and cast aluminum alloys.

This datasheet provides information on key alloy metallurgy, processing effects on physical and mechanical properties, and applications of Mg sand-casting alloy 520.0. Room-temperature aging characteristics for aluminum alloy 520.0-T4 are illustrated.

Ring rolling is a process for creating seamless ring shaped components using specialized equipment and forming processes. This article provides information on the applications of ring rolling. It discusses the types of machines used for ring rolling, namely, vertical rolling machines, radial-axial horizontal rolling machines, four-mandrel mechanical table mills, three-mandrel table mills, and automatic radial-axial multiple-mandrel ring mills. The article provides a discussion on the process control technology and ancillary operations of ring rolling. It describes the methods of producing ring blanks and the various types of blanking and rolling tools used in ring rolling process. The article concludes with a discussion on rolled ring tolerances and machining allowances.

This article summarizes some general alloy groupings by application or major characteristics. The groupings include cast rotor, general-purpose, elevated-temperature, wear-resistant, moderate-strength, high-strength, and high-integrity die casting alloys and cast aluminum alloys bearings. A table lists selected applications for aluminum casting alloys.

Alloys 6005 and 6105 were developed in the 1960s to be used in place of alloy 6061 in many applications. This datasheet provides information on chemical composition limits, fabrication characteristics, processing effects on physical and mechanical properties, and applications of medium-strength extrusion alloys 6005, 6005A, and 6105.

Thermal spray is a generic term for a group of coating processes used to apply metallic, ceramic, cermet, and some polymeric coatings for a broad range of applications. This article provides a brief description of commercially important thermal spray processes, namely, powder-fed flame spray, wire- or rod-fed flame spray, electric arc spray, plasma arc spray, vacuum plasma spray, high-velocity oxyfuel spray, detonation gun deposition, and cold spray, and their advantages. It provides details on the microstructural characteristics of thermal spray coatings. The article also presents information on a wide variety of materials that can be thermal sprayed, such as metals, ceramics, intermetallics, composites, cermets, polymers, and functionally gradient materials. Tables are included, which list the thermal spray processes and coating properties of importance for various industrial applications.