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Sprayed metal coatings have a characteristic structure which greatly influences their behaviour in corrosion processes. The coatings are built up from tiny particles of metal, of the order of 20 microns diameter, produced by atomising molten metal in a stream of compressed air. The metal is supplied to the spraying pistol either as a wire or a powder and is melted in an oxygen‐fuel gas flame. The metals of low melting point, including zinc and aluminium, are also applied by a pistol which receives molten metal from a heated reservoir.

The technique of atomizing molten particles of metal by a stream of compressed air has been established for many years. It is the principle used in all metal spraying where the atomized particles are directed at a target so as to produce a coating. Almost all metals and alloys and indeed many non‐metallic materials, can be deposited in this way but by far the most important is zinc. Minor uses of sprayed zinc include the production of moulds, or the provision of metallic conductors on non‐metallic surfaces, but the amount used for these purposes is insignificant when compared with the use of sprayed zinc coatings to prevent corrosion of steel. Several hundred tons of zinc have been deposited on very large structures such as the Forth or Severn road bridges.

In the first part of this article in our last issue P. L. HURRICKS considered the wear resistance of sprayed coatings when subjected to adhesive and abrasive action. In this part he is concerned with the friction of sprayed coatings on bearing and journal surfaces.

Plasticised wood. Wooden components as strong as those made of metal are said to have been obtained by Latvian chemists, who state that wood has been made stronger by a factor of 3½ following treatment with a 25% solution of ammonia and drying with high frequency currents. It will be used as a substitute for costly metals and plastics. A bearing bushing made of wood is claimed to be 10 to 15 times cheaper than one of bronze, and not inferior in quality. Arrangements are now in hand for a small pilot plant to produce 500 tons of such treated wood a year.

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.

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 high‐temperature corrosion tester described in this article has been used to establish the characteristics of the cooling water source to be used at English Steel Corporation's new Tinsley, Sheffield, project, and will also be used at Shell Chemical Co.'s establishment at Partington, nr. Manchester.

In September, The Corrosion Group of the S.C.I., The Institution of Gas Engineers, and The Birmingham College of Advanced Technology, held a joint symposium on the above subject in Birmingham. Certain well‐known authorities contributed papers on their own particular field as it affected the gas industry. Below are abstracts from some of the papers.

Independent Research There are three rational ways a firm may spend money on research in the U.K. Firstly there are the university or technical colleges in which the results are, or should be, available to all the world; then there are the co‐operative research associations when the results are available to competitors in the U.K. (and possibly abroad); and lastly there are the private or ‘captive’ laboratories set up by the firm itself which usually has complete control of the results. This latter method uses by far the largest share of total research allocation and is at worst reduced to carrying out routine laboratory production control and trouble‐shooting.

FAILURE of stainless steel in chloride solutions has been the subject of several investigations, and a recent communication has commented upon similar failures arising in alkaline conditions where heat transfer occurs. Although it is generally stated that cracking due to chlorides is invariably transcrystalline, and that due to alkalis is intercrystalline, Wanklyn and Jones have reported that both forms of failure occur in alkaline solutions.