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The electrochemical approach to corrosion problems has been stressed before, but here the author dwells more on the thermodynamic aspects since comparatively small changes in energy, and hence in chemical activity, which are caused by stress may result in very marked changes in the damaging effects of corrosion. Part 1 of the article opens with a thermodynamic approach covering borderline corrosion and the corrosion of crystals, and then deals with the effect of stress on chemical attack. Following this is a comprehensive survey of types of metal deformation (e.g. slip, cleavage and grain boundary movement) and concludes with data regarding the properties of grain boundaries and the effect of temperature and rate of loading. Stress corrosion is the major subject to be covered next month.

The two previous parts of this article dealt with such subjects as borderline corrosion, the corrosion of crystals, the effect of stress on chemical attack, and stress corrosion. In this final instalment the author' considers the effect of fatigue and alternating stresses on the corrosion process, and concludes by surveying the effects of fretting corrosion, and those of cavitation and impingement attack.

Part I of this article, published last month, was concerned chiefly with a thermodynamic approach to the subject, and covered such aspects as borderline corrosion, the corrosion of crystals, and the effect of stress on chemical attack. Also included was a survey of types of metal deformation, and data regarding the properties of grain boundaries and the effects of temperature and rate of loading. Now, in Part 2, the author considers the subject of stress corrosion, including the development of stress by the corrosion product.

THE Fulmer Research Institute was founded in 1947 to undertake confidential sponsored research for industry and/or government, British and/or foreign. Its founder, the late Col. Devereux, had been impressed by the work of sponsored research organisations such as Battelle, Armour, Stanford and others in the United States, and he believed that a similar organisation should have a role to play in the research effort of this Country. In 1947 this was a far‐sighted belief, for it seems probable that in those early post‐war years research and development were not recognised to the extent they are today, as essential parts of the processes of economic growth.

Introduction Before any metal is immersed, it is usually exposed for some time to the atmosphere. During this period the metal normally reacts with the oxygen present in the air and forms an oxide film. It may also combine with any moisture and dissolved gases in the atmosphere to produce surface films. The presence of these surface layers affects the rate, and possibly the distribution, of any subsequent corrosion. Hence the formation of surface films in the atmosphere is discussed before the corrosion of immersed lead.

ZIRCONIUM Corrosion in hot water and steam. Metallic zirconium and its alloys have assumed much importance as construction and protection material in nuclear reactors cooled with water or heavy water. Among the properties favouring this application are low neutron absorption, favourable mechanical characteristics, and a high corrosion resistance to water and steam. This corrosion resistance can be further improved by using suitable zirconium alloys. Even so, there are still certain undesirable corrosion phenomena which cause trouble. These have been made the subject of further research, e.g. in the metal laboratory of the Metallgesellschaft A.G., Frankfurt‐am‐Main. In this connection, a distinction must be made between two phenomena which occur simultaneously but are, as far as it's known at present, basically independent of each other, viz. oxidation and hydrogen absorption. But the extent to which the hydrogen freed in the course of the oxidation process can be absorbed by the zirconium and thereby cause brittleness depends not only on the external conditions but also on the type and quantity of the alloying components. During oxidation, the slow formation of a thin, bluish oxide film is liable to be followed by a more rapid ‘breakaway’ corrosion process in which a white oxide is formed that will soon peel off. There is, as yet, no satisfactory theory which would appear to provide a full explanation of all the phenomena encountered. The author discusses the research methods, the corrosion phenomena as such, the influence of certain alloying constituents on these phenomena and the various attempts at interpreting them.—(H. W. Schleicher, Metalloberfläche, 1961, 15 (8), 234–240.)

Certain classes of organic chemicals that can behave like carbon black in protecting polythene from thermal degredation have recently been developed at Bell Telephone laboratories in the U.S.A. Mrs. A. Worthington and Dr. W. L. Hawkins described their discovery at a recent meeting of the American Chemical Society in New York. They demonstrated that a number of compounds containing alternating unsaturated bonds provide excellent thermal anti‐oxidant properties in combination with previously reported sulphur‐bearing compounds.

MAGNESIUM AND ALUMINIUM Effect of RH of air on hydrogen peroxide formation in atmospheric corrosion. Means are described for maintaining a constant relative humidity of the air by providing at the bottom of the containers in which the tests are made NaOH solutions of definite concentration, in connection with which graphs were constructed showing relation between r.h. and NaOH concentrations, e.g. with r.h. of 15, 30, 45, 60, 75 and 90%. The photographic method was used for determining the relation between amount of metal removed or separating in atmospheric corrosion through hydrogen peroxide and r.h. Spectroscopically pure Al was used for test (Si 0.0016, Fe 0.0016, Cu 0.001%); also Mg (Fe 0.004, Si 0.009, Mn 0.0021%), in an atmosphere to which no aggressive media were added. Iso‐orthochromatic reproducing supercontrasting photographic plate was used of 1.4 sensitivity (Russian standard, G.O.S.T.). It had been found in earlier Russian work (I. L. Roikh, etc., Dokl. A.N., 1953–54) that the photographic response of metals is associated with the separation of H2O2 in atmospheric corrosion. Subsequent research revealed an actual linear relation between weight and thickness of the oxide film and separating H2O2 in the atmospheric corrosion of Al and Mg. With variation in r.h. from 0 to 90% there was linear relation between this content and separation of H2O2 in the atmosphere. The kinetics of separation of H2O2 by Mg and Al was studied during the first 6 hr. of atmospheric oxidation with r.h. of 0 to 60%. Fifteen references.—(I. L. Roikh and D. M. Rafalovich, Zh. prikl. Khim, 1961, (4), 864–870.)

The above Congress, being held at the Imperial College of Science and Technology, London, from April 10–15, has been described as likely to be the corrosion event of the decade. Size alone is no criterion, though over 80 papers are being presented, but the standing of many of the corrosionists associated with the Congress is, perhaps, the best indication of the truth of this statement. Summaries and abstracts of some of the papers appear in the following pages. More will be published in next month's issue.

The aluminium alloy BS. 1476 — HE.15, by virture of its high strength and low density, finds application in the form of bars or sections for cranes, bridges and other items of plant where a reduction in dead weight load and inertia stresses is advantageous. The basic composition of the alloy is as follows: