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Protected Ducking Rollers. Ducking rollers used in the pickling of continuous steel strip can now be fully protected against chemical corrosion. This development by Tanks & Linings Ltd. provides a roller with a plasticised PVC outer skin.

Inorganic oxide addition can be synergistically beneficial in organic coatings if it can impart anti-corrosion properties and also act as an additive to enhance physical and/or chemical properties. The aim of this study was to evaluate the anti-corrosion benefits of nano nickel zinc ferrite (NZF) in the polymer film.

The time-dependent anti-corrosion ability of NZF (0.12-1.0 per cent w/w NZF/binder), applied on API 5L X-80 carbon steel, was characterized by electrochemical techniques such as open circuit potential, electrochemical impedance spectroscopy, linear polarization resistance and potentiodynamic. Characterization of corrosion layer was done by removing coatings after 216 h of immersion in 3.5 per cent w/v NaCl. Optical microscopy, field emission scanning electron microscopy and X-ray diffraction techniques were used to characterize the corroded surface.

Corrosion measurements confirm the electrochemical activity by metallic cations on the steel surface during corrosion process which results in improvement of anti-corrosion properties of steel. Moreover, surface techniques show compact corrosion layer coatings and presence of different metallic oxide phases for nanocomposite coatings.

The suggested protection mechanism was explained by the leaching and precipitation of metallic ion on the corroded surface which in turn slowed down the corrosion activity. Furthermore, improvement in barrier properties of rubber-based coatings was confirmed by the enhanced pore resistance. This work indicates that along with a wide range of applications of NZF, anti-corrosion properties can be taken as an addition.

The purpose of this paper is to study the patterns of formation of anti-corrosion properties, the development of compositions for pigments by using the method of co-precipitation and subsequent heat treatment.

To obtain co-precipitated hydroxides, aqueous solutions of salts were used. The conditions of synthesis varied according to the following parameters: the nature of the starting salts of metals; and the ratio of metal cations. The anticorrosive activity of the pigments was evaluated by the potentiodynamic method, by comparing the anodic and cathodic polarization curves, and calculated potentials and corrosion currents on the basis of regions of Tafel on curves. Polarization curves were obtained by using Potentiostat/Galvanostat/ZRA Gamry, which connected to the PC, and by using the program Gamry Framework. The measurement results were processed by using the method of simplex-lattice planning. X-ray diffractograms of pigments were recorded on a DRON – 2.0 diffractometer (monochromatic copper radiation with a nickel filter).

The paper deals with the results of research the dependence of colour characteristics and anticorrosion properties of synthesized compositions on their nature and composition. The presence of aluminium cations leads to the formation of solid solutions of ferrum and aluminium oxyhydroxides.

The main technological properties of pigments are determined by the anionic and cationic composition. Colour characteristics are determined by the cation-chromophore. The anti-corrosive properties of non-calcined pigments are determined to a greater extent by the presence of the formed hydroxyl ions and the composition of the compounds. The greatest protective effect is observed when using double compounds of metals, the dissociation constants of which differ significantly. The protective effect is mainly determined by the slowdown of the anode process. Anions containing aluminium atoms accelerate the corrosion processes.

The increase in automobile corrosion problems stems largely from greater use of salts for ice and snow removal. Chemicals and water trapped in hidden cracks and crevices can continue to cause corrosion for long periods. This article, originally published in the December 1966 issue of ‘Materials in Design Engineering’, USA, describes what US automobile engineers are doing to beat the problem.

Among lubrication processes for cold forging of steel, phosphating is the most common. Depending on contact between piece and phosphating solution, the success of this treatment depends on steel surface preparation. Despite this obvious fact, the influence of cleaning pretreatments such as degreasing and acid pickling are seldom considered from a mechanical point of view and specially from a tribological one. Through a tribological test, the preparation of the surface of steel billets to be zinc phosphated and soaped was studied. Having shown the importance of degreasing, this study tries to connect the parameters of warm acid pickling, such as bath composition and dipping time to the tribological performances of the coated part.

METAL IN WOOD Corrosion of metal in wooden casings. Certain woods (e.g. beech and oak) contain up to 5% combined acid, mainly acetic acid. During furnace drying and steam treatment, a considerable quantity of acetic acid is released which, being volatile, is liable to promote corrosion through the gaseous phase. The dependence of this acid separation on the external conditions and the escape of the acid from the wood during storage have been investigated.

UNSOLVED CORROSION PROBLEMS. IF large numbers of stressed specimens of a specific metal or alloy are exposed simultaneously, why do some specimens fail by stress corrosion cracking while similar specimens do not?

CORROSION TESTS WITH ULTRASONICS ? IT is well known that the corrosion of iron, zinc, aluminium, magnesium, etc., is slower in moving water than in water at rest. This has been explained by the protective oxide film theory, i.e. the supply of oxygen to the metal surface is more adequate in moving water for the formation of complete films than in water at rest. When ultrasonic waves are used to stir the corroding solution in which the metal is immersed, the wet corrosion may be explained by a colloid science argument rather than by oxide film theory.

This paper reviews technologies used for the prevention of electromagnetic interference in current portable electronic products. It studies the need for future advanced products and some of the technologies likely to be available. The focus is on housing technologies and the products available for giving greatest electromagnetic compatibility with the latest European and other emission and susceptibility standards. It is concluded that new or improved approaches which are better able to ensure long‐term reliability will be essential for the 100 MHz clock speed equipment likely to be in production within the coming five years.

For some years now the dominant techniques for coating thickness have been based on electronic instrumentation. As such they have been subject to the same rigid progress which has been seen in the electronics industry. Components have become smaller and more complex and the microprocessor is pushing into more and more areas of control and measurement. Development of the various techniques has increased the range of coating‐substrate combinations that are measurable and improvements to stability have extended the measurement range. Statistical evaluation of results has been added to all but the simplest instruments. Describes the principal instrument types and in conclusion sees their intelligent use and the implementation of statistical process control as making the life of the organic finisher easier and more profitable.