Corrosion Hazard Research Articles

Assessment of Workplace Safety Symbols

Written signs are commonly used in industrial sites to provide hazard warnings and safety information. The use of safety symbols and pictorials may increase the effectiveness of safety communication, however, because such signs are language-free, and because they can be recognized more rapidly and accurately even under some conditions of interference and distraction. The effectiveness of safety symbols critically depends upon the selection of symbolic images which are readily understandable to the intended audience. A three-phase evaluation of a set of selected workplace symbols is described in the following paragraphs. First, thirty-three messages (referents) important to workplace safety were selected, based upon industrial site visits, sign catalogue review, and safety standard examination. These messages were divided into five categories: hazards; protective gear; first aid and emergency equipment; prohibited actions; and egress. Secondly, two to forty symbolic images were collected for each of the thirty-three referents. These images were rank-ordered according to their appropriateness for a given referent by thirty participants drawn from the graphics and safety communities. Three to five images for each referent (for a total of ninety-one images) were selected from the preference rankings for further experimentation, except for five messages where nationally standardized images already exist. These include laser, biohazard, radiation, fire extinguisher, and standpipe. The final set of images for each referent represented a range of abstraction, complexity, activity, and use of the human figure. (It was hypothesized that less abstract figures engaging in activity might be better understood.) The final phase consisted of two portions: determination of understandability and preference ranking. In the first portion, participants from industrial sites in three disparate geographical locations provided a short definition of the meaning of each image. The images were shown one at a time in a random order. Subjects saw only one symbolic image for each referent. Secondly, all the images for each referent were presented along with the meaning, and participants selected the image that best conveyed the intended meaning and indicated any reasons for the preference. Similar data were obtained from a pilot group of participants who were not familiar with workplace hazards, so that the effects of workplace experience on symbol understandability could be examined. Symbol understandability, in terms of percentage of correct responses and confusions, varied widely for the thirty-three referents and for the images tested for each referent. Despite standardized use for a number of years, the radiation, biohazard, and laser symbols were frequently mis-identified. Symbols for protective gear, first aid and emergency equipment were generally correctly identified. The different images selected for various hazards show the greatest range in understandability, with versions for entanglement, electricity, corrosion, and overhead hazard being quite different. Referent messages for which all symbolic versions received less than 85% correct responses included radiation, laser, biohazard, general warning, poison, combustible, eyewash, exit, no entrance and no exit. The first four referents do particularly poorly for both informed and naive participants. The preference data generally supported the understandability data, with the most correctly identified image usually being the most preferred image. Participants also provided insightful comments about the reasons for their choices, including ideas about the visibility, representativeness, and effectiveness of the images proposed for each referent.

Chemical Safety in Clinical Laboratories

Chemical safety topics that are widely applicable in clinical laboratory practice are reviewed, with emphasis on flammable, corrosive, poisonous and pressurized chemical hazards. The United Nations hazards classes are discussed, and precautionary labeling that should be used to identify these classes and their members is described. Fire, fire safety, corrosives, prevention of chemical burns of eyes and skin, protection from and detection of poisons, the hazards of compressed gases and cryogenic liquids, safe storage of incompatible chemicals, and management and disposal of hazardous and chemical wastes in compliance with emergent enforcement of the Resources Conservation and Recovery Act (RCRA) are among the topics discussed. Selected references that have been used in teaching chemical safety in the chemical industry and allied products and processes industries are also included.

Soil survey for urban development

As an aid to urban planning, a detailed soil survey is underway in the new Mill Woods district, City of Edmonton. Five soil associations — Ellerslie, Mill Woods, Argyll, Hercules, and Beaumont — are being mapped in the area. These soils represent the Chernozemic, Solonetzic, and Gleysolic Orders in the Canadian System of Soil Classification. Ellerslie and Beaumont soils are a good topsoil source and will support plant growth well. Argyll soils have poor surface drainage and being saline may present problems in lawn establishment and trafficability. The Mill Woods soils are intermediate between Ellerslie, Beaumont and Argyll associations. Hercules soils are poorly drained and may be saline; their suitability for landscaping purposes is limited. From an engineering or construction standpoint, the soils in the Mill Woods area may present some problems related to shrink—swell potential and concrete corrosion. The Argyll, Mill Woods and Hercules soil associations are characterized by a relatively high sulfate content which represents a potential concrete corrosion hazard in the area. The soil map also indicates areas of poorly drained soils which will require special engineering practices before development can be initiated.

Microbial Corrosion Hazard in Fuel Storage Tanks in the Presence of Corrosion Inhibitors

AbstractTests were carried out in five light fuel oil storage tanks placed outdoors in the vicinity of Stockholm, Sweden, to study the effectiveness of some commercially available corrosion inhibitors in the presence of certain micro-organisms. Corrosion in the aqueous phase caused by Desulphovibrio desulphuricans, Thiobacillus ferro-oxidans and Cladosporium resinae was effectively stopped by the addition of a sodium nitrite-sodium tetraborate mixture, but was enhanced by each of three commercial oil-soluble inhibitors. In some cases the corrosion rate exceeded 3 mm/year. The results are of a preliminary nature, but give cause for alarm and suggest the need for further investigation.

Reliability and corrosion

THE reliability of ships' structures and machinery is of utmost concern to activities in a marine environment. Corrosion can have a major effect on this reliability. A number of practical examples will be discussed to illustrate the corrosion hazards that appear between design office and field execution, the weaknesses inherent in some commonly used metals, and how an understanding of corrosion can be of major significance in ensuring reliability.

Successful Recovery Boiler Combustion Safeguard Systems

Numerous auxiliary fuel explosions in recovery boiler furnaces have caused heavy losses of life and property. Combustion safeguard systems involve a complex, exacting assemblage of electronic safety interlock control systems. Success demands the involvement of qualified electrical and electronics engineers in their development, application, testing, and maintenance. Environmental moisture, corrosion, vibration, and mechanical hazards make special electrical applications necessary. A successful safeguard system will take shutdown action without fail when monitored conditions deviate from preestablished safe limits, but high-quality systems for reliability are essential because competitive operation cannot tolerate frequent nuisance outages.

The Utilisation of Reinforced Plastics in the Wessex Helicopter to Prevent Corrosion

MAGNESIUM metal with its low density high strength and stiffness properties is a material which is used extensively in the Wessex helicopter for castings, forgings, and in sheet form in the skin stringer constructed fuselage. Extensive utilisation of these aircraft has shown that a corrosion hazard is present with this material in the fuselage application. Accidental damage, mis‐use and normal wear and tear removes the carefully applied organic protection permitting moisture to come into contact with the non‐protected metal, with the result that corrosive conditions are generated and it is found that in the non‐accessible areas, intensive corrosion damage occurs and it is not discovered in time for remedial action and the efficiency of the structure and airframe is impaired.

Recognition of Corrosion Hazards to Metals in Building

This paper outlines some of the conditions which affect durability at discontinuities in metals used in the building industry. The application of metals for lightweight cladding and the specific problems arising at crevices, dissimilar metal contacts, in run-off waters and chemical solutions and by stress corrosion are briefly considered. While individual problems of corrosion are not generally costly to rectify, collectively they Impose a heavy maintenance burden on the building industry. In this context it is argued that the faults Which occur could have been prevented by due recognition of the corrosion hazards.

Corrosion and Stress Corrosion of 5000-Series Al Alloys in Marine Environments

Abstract The 5000 series nonheat-treatable aluminum magnesium alloys are recognized as superior to other high-strength aluminum alloys for marine applications. However, a potential corrosion and stress corrosion hazard exists in these alloys from inter-granular precipitation of a magnesium-aluminum compound. This paper summarizes results of several long-term investigations of the effect of material condition on relative corrosion and stress corrosion behavior of representative alloys. Studies involving sea water exposure were conducted with plain and welded samples of Alloys 5083, 5086, 5154, 5356 and 5456. Several tempers and sheet gages were included, with exposure times up to five years for stressed and seven years for unstressed samples. General corrosion damage was mild, characterized by scattered shallow pitting. No stress corrosion cracking was encountered in standard mill tempers. However, sensitization of materials by holding one week at 212 F (100 C) to simulate long-time natural aging did resul...

Corrosion Notebook

Long life on the Dead Sea. The Dead Sea Scrolls Expedition faced severe corrosion hazards in addition to their literary‐archaeological problems when the metal surfaces and electrical circuits of their outboard motors were exposed to local conditions of extreme salinity and heavy condensation. The solution (to corrosion) was found in a silicone grease material Ambersil MS4, which was applied by aerosol to the metal surfaces and electrical circuits and succeeded in preserving these for the duration of the expedition.

Corrosion in POWER STATION CONDENSERS

At the end of the second world war the electricity generating capacity of this country lagged seriously behind the consumer demand. In order to rectify this deficit two standard sizes of generating set were adopted. These were the 30 and 60 megawatts (MW) generators. Since then, to improve the Rankine cycle efficiency, set sizes have steadily increased and today 200‐MW sets are accepted practice and 550‐MW machines are being designed. The increase in turbo‐alternator size has had repercussions on condenser design, some aspects of which may increase the corrosion hazard. This has stimulated interest in the development of effective countermeasures, especially the application of cathodic protection.

Electrodeposition of Iron from Aqueous Solutions Onto an Aluminum Alloy

Abstract Heavy metal contaminants such as copper, nickel and cobalt have long been recognized as corrosion hazards in aqueous solutions because their reduction is a comparatively common electrochemical corrosion reaction. It has been known for many years that Fe (III) is corrosive to various metals if the ferric salt is soluble, that is, if the solution is sufficiently acid to maintain the Fe (III) ion in solution. Metals such as aluminum, zinc, cadmium, iron, etc., reduce Fe (III) to Fe (II). Furthermore, if dissolved oxygen is available, more corrosive conditions can result by the oxidation of Fe (II) to soluble Fe (III). Recently a service situation was encountered where ferrous iron in solution was reduced to metallic iron as the result of electrochemical action in an aluminum alloy pipe handling a brine solution. This article describes the laboratory studies conducted to define the mechanism of iron electrodeposition on certain metal alloys from aqueous solutions. Methods to control or prevent such reduction are discussed.

History and Development of Some Problems Associated with CONTRACT CHEMICAL CLEANING

Abstract Author believes little more attention is being paid to corrosion control in chemical cleaning operations than was common in 1957 when the first NACE committee on the subject was organized. History of chemical cleaning is reviewed, with references to the literature dealing with the use of petroleum products, potatoes and other materials. First use of acids is described and some engineers’ comments on use of acids are reported. Following the introduction of inhibited acids for cleaning, the growth of contract cleaning is described. Some laboratory and field experience with cleaning by inhibited acid is described, and some of the corrosion and safety hazards examined. In considering the contract cleaning of plants with acids, the author cites the difficulties faced in attempting to establish specifications for the work in advance of contract letting. He deplores the practice of letting acid cleaning on the lowest bid without a full understanding between the parties of what is to be done. Writer suggests that the nature of the acid cleaning process is such, the potential hazards to persons and equipment so serious that industry would be advised to seek professional type services rather than let work on low bids. Some mention is made of cleaning agents other than hydrochloric acids and why contractors so far have shown little interest in them. 49 references. 5.9.2

CORROSION COMMENTARY

LIGHTING FOR INDUSTRY. Lighting equipment may be a particular source of danger under some industrial conditions, due to abnormal corrosion, or to the risk of explosion or fire. The corrosion and fire hazards include flammable liquids, vapours and dusts and some means of protection should, of course, be adopted to ensure safety in normal operation and also under faulty conditions. Precautions should also be taken against any chemical agents present in the atmosphere, perhaps accentuated by weather or heat.

Cathodic Protection of Lead Cable Sheath In the Presence of Alkali from Deicing Salts★

Abstract It had been shown previously that complete protection of sheath could be effected in a constant current system even in the presence of high salt content and pH. The relationship of protective potentials to pH and salt concentration has now been established for commercial lead sheath alloy composition and is shown to be substantially the same as given in the Pourbaix diagram for pure lead. The use of a potential gradient for lead cathodes was developed to provide simulated duct tests. The data from the gradient tests provided information on the effects of salt concentration, pH and potential on the corrosion behaviorism of lead when fully immersed and partially immersed. The criteria for effective cathodic protection are shown to be different for the portions of the lead cathode below, at and above the water line. The most severe corrosion conditions at the air-solution interface require a more negative voltage for protection than below the interface. The distribution of potential along the gradient as a function of salt content, type of salt and current input to the cell shows some important aspects to be considered in the field as possible regions of corrosion hazard. 7.7

Intrinsic Protection of Water Mains

Abstract Inherent protection against corrosion hazards is essential in water supply systems. External corrosion is reduced by the use of cement coatings and separation of heterogeneous line sections. Internal galvanic action, especially in prestressed concrete structures, is eliminated by separation or matching of materials. A complete solution of the problem is attained only by electrically nonconducting pipe. Internal corrosion and blocking of pipes can be prevented by water treatment. Investigations on an irrigation system confirm that bare or bituminous coated steel components are anodic to cement coated lines. Irrigation outlets during the dry season also usually are anodic to the trunk line. In anodic areas a chemical absorption process takes place in the cement coating, which intrinsically increases its protective value. The presence of an adequate layer of pure cement over the steel surface is essential for this protective effect. 7.2

The Lighting of Hazardous and Corrosive Locations in Industrial Plants

At the twelfth session of the C.I.E. a committee was formed to study the lighting of hazardous and corrosive locations. This paper, by reviewing British practice in some detail, amplifies the report prepared by Great Britain as secretariat country. The nature of lire, explosion and corrosion hazards in industry are discussed in relation to lighting practice, the regulations are summarised and examples are given of modern practice.

CORROSION COMMENTARY

CORROSION HAZARDS IN SURGERY. AN elegant experiment with radioactive isotopes has revealed the cause of corrosion of metal plates used in surgery for repairing broken bones. It had been thought that the reason for this corrosion was the transfer of traces of foreign metal from the screwdriver to the screws used to fix the plates. This has been confirmed by scientists of the Royal Infirmary, Bradford, and the Department of Physical Chemistry, Cambridge, who incorporated radio‐chromium in a surgical screwdriver and measured the amount of radio‐activity transferred to the screws. The two metals in contact may set up an electric cell which can cause the serious condition which prevents healing known as electrolytic inflammation. The experiment was described in a paper presented at the 2nd Radio‐Isotope Conference held in Oxford recently.

CORROSION COMMENTARY

CAR CORROSION HAZARDS. IN this issue we present the first of a series of three articles on corrosion in the motor car by a scientist of the Motor Industry Research Association. In this first article he discusses corrosive wear of piston rings and cylinders. Other aspects, including corrosion of the cooling system, will be dealt with later. The size of the cooling system problem may be gauged from the fact that in the U.S. something like 700,000 radiators have to be replaced each year owing to corrosion damage caused by antifreeze chemicals. In addition, an even greater number of cooling system ancillaries such as thermostats and water pumps have to be replaced. The best makes of antifreeze contain a corrosion inhibitor. In practice, however, minerals in the water, corrosive exhaust gases from a leaky cylinder‐head gasket and even air seeping into the cooling system eventually destroy the inhibitor's effectiveness. Frequent replacement of antifreeze is advisable until more effective corrosion‐prevention methods are devised.

Mercury and Its Compounds—A Corrosion Hazard

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation M. H. BROWN, W. W. BINGER, R. H. BROWN; Mercury and Its Compounds—A Corrosion Hazard. CORROSION 1 May 1952; 8 (5): 155–164. doi: https://doi.org/10.5006/0010-9312-8.5.155 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest Search