The effect of hydrogen on general corrosion of pure iron and ferritic steels, Si-Mn alloy and Mn-Mo alloy, was investigated in acid solutions. Hydrogenation was carried out in 10-280atm hydrogen at 450°C for 16hr. Corrosion loss of ferritic steels containing hydrogen was markedly greater than that of hydrogen-free specimens, and increased with increasing hydrogen content. Anodic polarization curves of pure iron and Si-Mn alloy steel containing hydrogen in 1N-H₂SO₄ solution exhibited an increase of current density in the passive region in agreement with corrosion data. These anomalous corrosion was partly recovered by dehydrogenation heating at 300-950°C. Deformation increased the occluded hydrogen content and anomalous corrosion loss. The anomalous corrosion was only responsible for the residual hydrogen content independent of the structure. It is suggested that the anomalous behavior is caused by activated internal microdeffects formed by hydrogen trapping.

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Combination chloride-selective microelectrode which is based on silver-silver chloride has been developed for the corrosion study. The assembly of the combination chloride-selective microelectrode with double-junction type consists of microcapillary tip of 1μm in diameter for the reference microelectrode and 150μm for the chloride-selective microelectrode. The body of the microelectrode is supported with acrylic tube. The microelectrode potentials were stable within±1mV for 8 days. The response of the microelectrode potential was very rapid even in the test solution of low chloride concentration, and the potentials (EMF) were steadily reproducible. Concentration range for practical use was 1.5-10^-4M in sodium chloride solution. The potential did not change over the range of pH 1-12. The selectivity ratios were as follows. K_{C1 Br}=4.4, K_{C1 I}=1×10^-2 (pI^->5), K_{C1 NO3}=6×10^-3. Accumulation of chloride ions in the crevice of stainless steel (SUS 304) were measured as a function of time.

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The international system of units (SI) is rapidly gaining global acceptance. The use of SI and changing from gravitational system of metric units to SI are described.

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This paper describes inorganic coating materials including spraying, PVD, CVD, oxide coated electrode and glasslining.
Descriptions are made of plasma jet spraying in spraying section; vacuum evaporation, spattering and ion plating in PVD section; TiC coating in CVD section; DSA in oxide-coated electrode section and coating characteristics in glasslining section.

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