BaTiO₃ powder was flame-sprayed onto iron substrate and physical, mechanical and electrical properties of the coatings were investigated.
As a result, the following conclusions were drawn.
(1) The crystal structure turned into cubic by flame-spraying. The bond strength of the coatings decreased with the increase of thickness and the strength abruptly decreased at the thickness of 80μ.
(2) The roughness of surface had a close relation to the distance of spraying. The minimum value of 1.7μ Ha was confirmed at 8cm.
(3) The maximum dielectric constant was 780. The other properties were almost similar to those of rod-sprayed coatings; in short, they were intermediate between those of ceramics and rod-sprayed coatings.

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The effects of chemical compositions of base steel on the thickness of hot dipped zinc coating was investigated on commercial galvanized materials. The following results were obtained.
(1) In short immersion time, the thickness of hot dipped zinc coating rather depended upon surface conditions of specimens or operations of galvanizing than chemical compositions of base steel. However, in long immersion time, the thickness mainly depended upon chemical compositions of base steel.
(2) Si content had the greatest effects on the thickness of coating. The thickness increased with the increase of Si content. The effects of other elements were not so evident as Si.
(3) Amount of diffused steel into the molten zinc had a close relation to the thickness of coating. Most of dispersed Fe in galvanized coating was present as Fe-Zn alloy layer, but a part of Fe was in the molten zinc bath.
(4) When the thickness of coating was required to increase on the steel material, Fe-Zn alloy layer was apt to appear on the surface of galvanized coating owing to the reaction of the alloy formation during the time from taking out of the bath to water quenching.

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Fe-Si alloys having various Si contents of 0-14% were prepared by sinter siliconizing and subsequent diffusion treatment according to the procedure described in the author's previous report. Anodic polarization behaviors of the prepared specimens in 2N H₂SO₄ were investigated by the potentiostatic method.
For the specimens having Si contents up to 6%, both of the maximum current density at the active state and the corresponding potential indicated each constant value, independent of Si content. At above 6% of Si content, however, the maximum current density decreased with the increase of Si content and the corresponding potential shifted to be less noble.
Effects of Si content on the passive current density were quite different from those of abovementioned. That is, the passive current density increased with the increase of Si content up to 6%, but decreased with the increase of Si content above 6%.
The anodic polarization was measured in 1 and 0.5N H₂SO₄ by using specimens having Si contents of 6 and 14%. The polarization for 6% Si specimen was only affected by concentration of H₂SO₄ and the potential range of the active state was extremely extended. In other words, 6% specimen was much less to be passive than other specimens when H₂SO₄ solution was diluted to 1 or 0.5N from 2N. It was confirmed by the author's another experiment that the above results mainly depended upon SO₄^-- concentration in H₂SO₄ solution.

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The effects of the type of current waves and addition agents on the number of electrodeposited nuclei were investigated on the buffed cold rolled steel plates from the bath containing 60g/l of stannous sulfate and 50g/l of sulfuric acid.
(1) The effects of the type of current waves:
The number of electrodeposited nuclei increased very slightly according to the change of pulsating current, and it also depended on interrupting time (T₂) when interrupted current was used. Maximum number of nuclei was obtained for T₂=1sec in 1A/dm², or it was the value as large as 2.5 times of that in linear current. In P.R. current, the number increased with the increase in ratio (Q) of the quantity of positive electricity (in coulomb) to that of negative one.
(2) The effects of addition agents:
The number of nuclei increased with the increase in the each addition amount of gelatine or β-naphtol. Gelatine was more effective than β-naphtol and the former gave the maximum number at the concentration of 0.5g/l. When the above two agents were used together, the number was 7 times as large as the case of no agents by synergistic effects. When cresol sulfonic acid was used as an agent, a peak appeared at 100g/l, as it had a different behavior from that of the above agents.

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