Corrosion environmental effects

Compared with ferritic carbon and low-alloy steels, relatively little information is available in the literature concerning stainless steels or nickel-base alloys. From the preceding section concerning low-alloy steels in high temperature aqueous environments, where environmental effects depend critically on water chemistry and dissolution and repassivation kinetics when protective oxide films are ruptured, it can be anticipated that this factor would be of even more importance for more highly alloyed corrosion-resistant materials. 

In a previous section it has already been observed that high-strength 2000 and 7000 series alloys are sensitive to the presence of water vapour in corrosion fatigue tests. Stress-corrosion susceptibilities of these alloys in low temperature aqueous solutions and the effect of composition and heat treatment have been widely investigated . It is not surprising therefore that when subjected to corrosion fatigue in similar environments, substantial environmental effects can be observed particularly at low frequencies of less than 1 Hz and AA values above These environmental effects tend to be... 

Whilst careful design and informed forethought can often minimise or even prevent corrosion at little extra cost where the environmental conditions or the conditions of service are severe (as in most forms of marine and offshore engineering) reliable, secure and cost-effective corrosion control cannot be effectively achieved without considerable expense, although even in these circumstances good design can help to significantly reduce this. In... 

A list of danger categories is given in Table 14.2. Note that chemicals may possess several hazards, e.g. nitric acid is classed as both an oxidizer and a corrosive. If a chemical is not in one of these categories it is not generally considered to be dangerous. If the hazards of a new chemical have not been established it should be labelled Caution - substance not yet fully tested . Mixtures can be classified either from results from tests on the preparation, or by calculation to predict the health effects of the product based on the properties of individual components and their concentration in the mixture. Preparations need to be classified for both physico-chemical and health effects but, to date, not for environmental effects. 

Some of the most dramatic environmental effects of acid deposition have involved buildings, statues, monuments, and other structures made of metal and stone. The explanation of this kind of damage is obvious Acids in acid deposition react with metals and with many of the compounds of which rock and other building material are made. For example, corrosion occurs when metals such as iron are exposed to hydrogen ions in the presence of oxygen ... 

Waste oil, although contaminated, has a high energy value, and burning as a fuel is a major outlet for used oil. Unfortunately, used oil contains high concentrations of metallic contaminants, and its combustion can cause adverse environmental effects. Some of the metallic materials in used motor oils are introduced during use. Typically, the metals introduced by means of wear or corrosion are aluminum, copper. 

This development was further accelerated when, in the late 1970s and early 1980s, chromates began to fall out of favor (for both environmental and occupational health reasons), and thus the need arose to find suitable (organic) alternatives for use as effective corrosion inhibitors. Various stabilized phosphate and zinc/organic programs were developed at this time... 

R. C. Tennyson and W. D. Morison, Atomic-Oxygen Effects on Spacecraft Materials, Materials Degradation in Low Earth Orbit Proceedings of a Symposium Sponsored by the TSM-ASM Joint Corrosion and Environmental Effects Committee, held at the 119th Annual Meeting of the Minerals, Metals and Materials Society in Anaheim, CA, 17-22 February 1990, Eds. V. Srinivasan eind B. A. Banks (Minerals, Metails cind MateriaJs Society, Warrendale, PA, 1990) pp. 59-75. 

Corrosion, the degradation of a material s properties or mass over time because of environmental effects, is a costly reality that effects every industry. A study issued by the Federal Highway Administration (FHWA) in 2002 conservatively estimates the annual direct cost of corrosion in all U.S. industry sectors at US 276 billion. Costs associated with corrosion include cathodic/anodic protection coatings inhibitors corrosion-resistant alloys and materials and maintenance, repair, and depreciation of equipment. Indirect costs, such as lost productivity, environmental or product contamination, planning and design, and lost opportunities, can easily outpace direct costs by factors of two or more. 

Environmental Effects on Metallic Corrosion Products Formed in Short-Term Atmospheric Exposures... 

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