Electrodeposition of tin and tin-lead alloys from seven kinds of baths of alkanolsulfonic acids (carbon number: 2-6) was studied to obtain bright deposits. It was found that alkanolsulfonic acids having a short carbon chain as well as a hydroxy group bonded to a carbon near the sulfonic acid group can be used to give smooth and bright deposits. Throwing power and cathode current efficiency of these baths were nearly the same as those of phenolsulfonate bath. In the case of electrodeposition from 2-propanolsulfonate bath the lead percentage of the deposit was independent of current density.

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Auger electron and infrared reflectance spectra have been measured for the tantalum oxide films anodized in phosphoric acid solution to investigate the film structure. Regardless of the types of dissociated species, only phosphate was detected up to a half of the films formed in 0.1M phosphoric acid solution. When tantalum was anodized in phosphoric acid after anodization in nitric acid two different types of behavior were observed, depending on whether the second anodizing voltage was higher or lower. At higher voltage, phosphate was detected in the film, whereas at lower voltage no phosphate was detected. Thus it was found that phosphate was incorporated in the films only when the new anodic film was formed. In view of the results of IRRS of tantalum anodic oxide films, surface of which was removed by Vermilyea's acid, 1, 110cm^-1 band would be assigned to be PO₄. Relative value of 925cm^-1 and 850-860cm^-1 bands changed to some extent with increasing etching time. This phenomenon will result from the plural layer structure. The film consists of tantalum oxide with or without phosphate and tantalum excess oxide. From these results the mechanism of film growth explaining the phosphate distribution is discussed.

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Attempts have been made to find out the causes for contaminations and their influence on the surface reactivity of cold rolled steel sheets. Under annealing atmosphers, equilibrium of iron oxidation and that of carbon deposition have been investigated by measuring atomic pressures of oxygen, hydrogen, carbon, and nitrogen at each annealing temperature. DX gas produced an oxide film consisting of (FeMn) O⋅Fe₂O₃, which was identified by means of electron diffraction, and also deposited a carbon layer, whose concentration on the surface was measured quantitatively by electrolysis extraction method. Rolling oil produced residual carbon as well. It was revealed that these contaminants caused anomalous growth and foreign bonding of phosphate crystals on the steel surface, which resulted in a marked deterioration of corrosion resistance of painted steel. The extent of the deterioration could be estimated previously by the method of Photo-Volt electric comparametory on the nital etched annealed sheets.

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The chemical structure of the conversion coated film formed on zinc plated sheet by cathodic electrolysis of aluminum biphosphate solution was studied. The structure of the conversion film was determined by using X-ray diffraction, EPMA, chemical analysis, infra-red spectroscopy, TGA, and DSC. As a result of X-ray diffraction it was found that the film had an amorphous structure. The constituents of the film were determined to be P, Al and O by EPMA and chemical analysis; the amounts of Al and P were estimated 13.9% and 17.2%, respectivelly. Infra-red analysis indicated that the chemical structure of the conversion film was hydrated aluminum phosphate, and the amount of bound water was determined to be 12.3% by TGA and DSC. From these data it can be shown that the conversion film is actually an inorganic polymer consisting of a three-dimensional network of polymerized aluminum phosphate bonded with an OH bridge.

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