CORROSION RESEARCH ROUND‐UP

GERMANY Thin sheet metal linings. In a recent German congress on chemical technology a report was included on the development and practical testing of a new method for the corrosion protection of technical apparatus, vats and tanks made of steel, concrete or masonry. A very thin high‐alloy sheet metal of 0.6 mm. thickness, 1 m. wide and 3 m. long is used as a protective lining. Before this method, which differs in several respects from all known methods of a similar kind, could be applied in practice several problems had to be solved. It was necessary to develop a welding technique which fulfilled all the requirements as to the flush, gas‐proof and liquid‐proof attachment of the lining to the base. For this purpose special automatically controlled spot welding equipment is used. The joints between the sheets are argon‐arc welded, with as little air gap as possible. In each case it is necessary to observe certain precautions in the preparation of the surface to be coated and of the welding seams. The protective linings thus produced have been tested for their mechanical and anti‐corrosive properties and were found to be well suited for the purpose of corrosion protection where plastic or ordinary rolled sheet linings could not be used for technical or economic reasons.— (P. Voigt, Werkstoffe & Korrosion, 1955, 6, 337.)