Search Results for atmospheric testing

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.

This article provides information on predesign surveys and the various testing procedures associated with wastewater treatment plants. These include soil testing, atmospheric testing, and hydrogen sulfide testing. The primary parameters that influence the production of sulfides within the piping system that transports the wastewater to the treatment facility are discussed. The article describes the corrosion performance of various materials in the soil, fluid, and atmospheric exposures. These include concrete, steel, ductile iron, aluminum, copper, brass, stainless steel, and coatings used for wastewater facilities.

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 provides information on the most frequently used atmospheres in commercial sintering of powder metallurgy iron and steel materials. These include endothermic, exothermic, dissociated ammonia, pure hydrogen, and nitrogen-base atmospheres. The article discusses sintering of iron and iron-graphite powder, iron-copper and iron-copper graphite, and alloy steels. The effects of various sinter conditions on the amount of combined carbon formed in the steel are also discussed. The article concludes with information on high-temperature sintering and sinter hardening.

This article focuses on the testing and typical corrosion behavior of coating-substrate systems in aqueous solutions and humid aggressive atmospheres. It includes a short review of the fundamentals of corrosion, followed by a discussion of specific system behavior, electrochemical and laboratory accelerated tests, and simulated service tests. The article also contains examples of different types of corrosion damage and presents guidelines for improving corrosion resistance.

Galvanic corrosion, although listed as one of the forms of corrosion, is considered as a type of corrosion mechanism that is evaluated by modifying the tests used for conventional forms of corrosion. This article focuses on component testing, computer and physical scale modeling, and laboratory testing methods of evaluating galvanic corrosion. The laboratory tests fall into two categories, namely, electrochemical tests and specimen exposures.

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 discusses the elements necessary for a galvanic cell operation. Detailed information on the possible corrosion reaction as a function of aqueous electrolyte concentration and pH, in the presence of certain ions, are provided using Pourbaix diagrams. A variety of atmospheric factors, climatic conditions, and air-chemical pollutants that determine the corrosiveness of the atmosphere and contribute to the metal corrosion process are discussed. The article reviews the phenomenon of precipitation runoff on the corroded metal surface and the corrosive microbial effect on metals. It describes the thermodynamics of atmospheric corrosion and models for predicting the corrosion damage of metals. The article concludes with information on the various trends in atmospheric corrosion research and methods for the corrosion processes.

This article, primarily focusing on atmospheric corrosion of carbon and low-alloy steels, describes the factors that must be considered by alloy casting users in material selection. It presents compositions of cast steels tested in atmospheric corrosion in a tabular form. The article graphically presents the results of a research program that compared the corrosion resistance of nine cast steels in marine and industrial atmospheres. It provides a comparison of corrosion rates of cast steels, malleable cast iron, and wrought steel after three years of exposure in two atmospheres. Conclusions drawn from these tests are also presented.

Weathering steels contain deliberate additions of alloying elements intended to increase the atmospheric corrosion resistance of steel. This article provides an overview of atmospheric corrosion testing. It describes the estimation of the atmospheric corrosion behavior of weathering steels by two methods such as short-term exposure tests and calculation of a corrosion index based on the steel composition. The article highlights some generalities about corrosion mechanisms. Based on the mechanism of atmospheric corrosion resistance of weathering steel, working rules for creating the protective oxide film have evolved. The article also provides case histories that illustrate both the violations of these rules and suggestions on how to avoid certain maintenance problems that may be encountered with weathering steels.