This article discusses the specimen preparation techniques for zinc and its alloys and zinc-coated specimens, namely, sectioning, mounting, grinding and polishing, and etching. It describes the characteristics of lead, cadmium, iron, copper, titanium, aluminum, magnesium, and tin, which are present in the microstructure of zinc alloys. The article also provides information on microexamination that helps to determine the dendrite arm spacing, as well as the grain size, grain boundaries, and grain counts.

This article describes the specimen preparation steps for tin and tin alloys, and for harder base metals which are coated with these materials with illustrations. The steps discussed include sectioning, mounting, grinding, polishing, and etching. The article provides information on etchants for tin and tin alloys in tabular form. It presents the procedure recommended for electron microscopy to determine the nature of the intermetallic compound formed by the reaction between tin or tin-lead coatings on various substrates. The article concludes with an illustration of the microstructures of tin-copper, tin-lead, tin-lead-cadmium, tin-antimony, tin-antimony-copper, tin-antimony-copper-lead, tin-silver, tin-indium, tin-zinc, and tin-zinc-copper systems.

This article reviews various phases and constituents found in the microstructures of low-carbon and coated steels. It provides information on the criteria for selecting proper metallographic procedures. Techniques used to prepare metallographic specimens of low-carbon steels and coated steels, such as sectioning, mounting, grinding, polishing, and etching, are discussed. The article also reviews the simple and proven manual sample preparation techniques of coated steel specimens.

From the standpoint of corrosion protection of iron and steel, metallic coatings can be classified into two types: noble coatings and sacrificial coatings. This article focuses on hotdipped zinc, aluminum, zinc-aluminum alloy and aluminum-zinc alloy coatings. It discusses the Sendzimir process and the Cook-Norteman process, which are the two commercial processes that are used for almost all hot-dip galvanized sheet steel in the United States. The article provides a discussion on the aqueous corrosion and atmospheric corrosion of galvanized steel and aluminized steel, as well as the intergranular corrosion of galvanized steel.

This article describes the zinc and zinc alloys for decorative and functional applications. It focuses on the types of zinc coatings, namely, hot dip galvanizing, electrogalvanizing, metallizing, and mechanical galvanizing. The article covers the uses of zinc alloy castings, including pressure die castings, and gravity castings. It details the wrought products of zinc and zinc alloys, including flat-rolled products, wire-drawn products, extruded products, and forged products. The article also describes various properties of zinc alloys, including mechanical, thermal, electrical, chemical, and magnetic properties. The listing for each alloy includes chemical compositions, relevant specifications, mass characteristics, and fabrication characteristics.

A sacrificial coating applied to a steel substrate can add 20 years or more of life to the substrate, depending on its thickness and composition. Different techniques to apply sacrificial coatings offer various characteristics that contribute to corrosion resistance. This article discusses thermal spray, hotdipping, and electroplating processes used to apply coatings in steel structures. It describes the corrosion attributes of the resulting coatings and discusses the methods of protecting steel from corrosion using aluminum and zinc coatings.

Environmental and worker health regulations have increased the costs associated with cadmium coating application and cadmium-beating waste disposal, thus creating economic incentives for industrial users to seek cadmium plating replacements. This article presents a cadmium replacement identification matrix that includes information on the specifications, corrosion control performance, environment-assisted cracking, coating lubricity, environmental and worker health regulations, and cost and performance factors for various replacement processes.

Several factors contribute to marine-atmospheric corrosion with the local environment being the single most important factor. Therefore, assessing a local environment, which is essential to reduce the gross expenditure, is assisted by modeling of the local environment and by a set of corrosion standards proposed by the International Standards Organization (ISO). This article focuses on the important variables associated with atmospheric corrosion in marine atmospheres, namely, moisture, temperature, winds, airborne contaminants, alloy content, location, and biological organisms along with their corresponding assessing methods. It also examines the ISO CORRAG program for modeling the corrosion rate of atmospheric corrosion that is represented as equations modeling.

This article is a brief guide to information sources on thermal spray technology. The sources provided by ASM International and the Thermal Spray Society (TSS) include magazines and journals as well as reference books, including the ASM Handbook series, conference proceedings, newsletters, education courses, and videos. The article provides information on the specifications, standards, and quality control for coatings.

Surface coatings are essential in all facilities that process nuclear materials or use nuclear fission for power generation. This article describes the coatings used in two basic types of Generation 3 nuclear reactor designs in the United States and their containment size. These reactors are the boiling water reactor (BWR) and pressurized water reactor (PWR). The article provides information on the loss-of-coolant accident (LOCA) identified as the design basis accident (DBA), which can rapidly de-water the core of an operating nuclear reactor. To avoid LOCA, both the BWR and the PWR include emergency core cooling systems. The article describes a DBA test and other coating performance parameters necessary for safety-related coating systems. It provides a detailed account of the selection criteria of coating types in a nuclear plant. The article concludes by highlighting protective coating strategies in Generation 3 Plants.

Independent verification of coating system performance can be based on laboratory testing and/or field exposure. Qualification testing is a critical component to coating system selection. This article focuses on performance evaluations that are used to prequalify coating systems, namely, facility-specific, industry-specific, coating-type-specific, or a combination of these. It describes the standard laboratory tests used to generate performance data, namely, physical, compositional, chemical exposure, and application characteristics tests. The pros and cons of using manufacturer-generated data versus independently generated data are discussed. The article provides information on accelerated corrosion/weathering testing and nuclear level 1/level 2 service coatings qualification. It also describes the procedures for establishing minimum performance requirements and for determining when requalification testing may be required.

Simulated service testing is the most reliable predictor of corrosion behavior that is important for specific objectives. These include materials selection, predicting the probable service life of a product or structure, evaluating new commercial alloys and processes, and calibrating laboratory corrosion tests in short of in-plant tests and actual service experience. This article provides a detailed discussion on the types of atmospheres used in simulated service testing. It describes the specifics of atmospheric-corrosion test that include equipment, test arrangement, and test specimen; factors affecting atmospheric corrosion; and evaluation of exposed atmospheric-corrosion panels. The article concludes with a discussion on the empirical model used for analyzing the atmospheric-corrosion measurements for estimating the service life of the part being evaluated.

Aluminum and its alloys are highly corrosion resistant, protected by a self-healing oxide film that effectively passivates the underlying surface. This article examines the various processes by which the protective layer can be breached and the types of corrosion that can occur. It describes pitting, galvanic, and atmospheric corrosion as well as stress-corrosion cracking, corrosion fatigue, and erosion corrosion. It also covers intergranular, exfoliation, filiform, deposition, and crevice corrosion and special cases of corrosion in soils, seawater, and automotive coolant systems. The article provides an extensive amount of data as well as information on coatings, claddings, and cathodic protection methods; the effects of composition, microstructure, and surface treatments; and the compatibility of aluminum with food and various household and industrial chemicals.

Steel sheet is often coated in coil form prior to fabrication to save time, reduce production costs, and streamline operations. This article examines the most common precoating methods and provides a metallurgical understanding of how they impact the manufacturability, performance, and service life of the host material. The article covers metallic coatings, including zinc, aluminum, zinc-aluminum alloys, tin, and terne; pretreatment or phosphate coatings; and preprimed and painted finishes based on organic coatings.

Liquid metal induced embrittlement (LMIE) is the reduction of the fracture resistance of a solid material during exposure to a liquid metal. This article discusses the mechanisms and occurrence condition of LMIE and describes the effects of metallurgical factors, such as grain size, temperature and strain rate, stress, inert carriers, and fatigue, on LMIE. It provides a detailed discussion on LMIE in ferrous and nonferrous metals and their alloys. In addition, the article highlights the ways of preventing embrittlement in metals and alloys.

This article discusses the generic situation of steel reacting with the environments found in structures. Two environments are specifically discussed: atmospheric and cementitious. The article describes the utility of different corrosion protection methods for atmospheric corrosion and cementitious systems. It presents examples of problems that have arisen in the corrosion performance of steel.

Corrosion of metals is defined as deterioration caused by chemical or electrochemical reaction of the metal with its environment. This article provides information on corrosion of iron and steel by aqueous and nonaqueous media. It discusses the corrosive environments of carbon and alloy steels, namely atmospheric corrosion, soil corrosion, corrosion in fresh water and seawater. The article describes the corrosion process in concrete, which tends to create conditions that increase the rate of attack. The focus is on the stress-corrosion cracking of steels; an environmentally induced crack propagation that results from the combined interaction of mechanical stress and corrosion reactions. The article tabulates a guide on corrosion prevention for carbon steels in various environments. It also discusses protection methods of steel from corrosion, including coatings, such as temporary protection, cleaning, hot dip coating, electroplating, thermal spray coatings, conversion coatings, thin organic coatings, and inhibitors.

This article focuses on the various forms of corrosion that occur in the passive range of aluminum and its alloys. It discusses pitting corrosion, galvanic corrosion, deposition corrosion, intergranular corrosion, stress-corrosion cracking, exfoliation corrosion, corrosion fatigue, erosion-corrosion, atmospheric corrosion, filiform corrosion, and corrosion in water and soils. The article describes the effects of composition, microstructure, stress-intensity factor, and nonmetallic building materials on the corrosion behavior of aluminum and its alloys. It also provides information on the corrosion resistance of anodized aluminum in contact with foods, pharmaceuticals, and chemicals.

This article summarizes the fatigue and fracture resistance of selected magnesium alloys. It reviews the effects of surface condition and test variables on fatigue strength. The article also provides an overview of the fatigue crack growth, fracture toughness, and stress-corrosion cracking of magnesium alloys.

This article aims to survey the factors controlling the weldability of carbon and low-alloy steels in arc welding. It discusses the influence of operational parameters, thermal cycles, and metallurgical factors on weld metal transformations and the susceptibility to hot and cold cracking. The article addresses the basic principles that affect the weldability of carbon and low-alloy steels. It outlines the characteristic features of welds and the metallurgical factors that affect weldability. It describes the common tests to determine steel weldability. There are various types of tests for determining the susceptibility of the weld joint to different types of cracking during fabrication, including restraint tests, externally loaded tests, underbead cracking tests, and lamellar tearing tests. Weldability tests are conducted to provide information on the service and performance of welds. The major tests that are discussed in this article are weld tension test, bend test, the drop-weight test, the Charpy V-notch test, the crack tip opening displacement test, and stress-corrosion cracking test.