Boronization of iron was studied by X-ray diffraction when it was dipped in a hot salt bath containing ferroboron and any one salt of NaCl, KCl, BaCl₂, Na₂CO₃, and borax.
The results obtained were summarized as follows:
1) The main reaction for the formation of boronized layer seemed to be the reaction between iron and boron which has been produced by the reduction of borax with aluminum contained as an impurity in ferroboron; and the secondary reaction would be the reaction between iron and boron contained in ferroboron which has been dissolved in any one salt of NaCl, KCl, BaCl₂, and Na₂CO₃.
2) The dissolution of boron (contained in ferroboron) in any one of the four salts was deboronization of ferroboron expressed by the following two equations:
2FeB→Fe₂B+B……(1)
Fe₂B→2Fe+B……(2)
3) It was confirmed by X-ray diffraction that boron in Fe formed an interstitial solid solution.
4) Boronization of iron or steel would be possible by means of the reduction of borax with any one substance of ferroaluminum, aluminum, magnesium, and calcium.

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Corrosion tests and measurements of anodic and cathodic polarization curves of aluminum were conducted in hydrochloric, sulfuric, nitric, and oxalic acids at pH=0 and 1. The results obtained were as follows:
1) The values of corrosion rate at pH=0 in the acids used were as follows:
In hydrochloric acid 77.1mdd (mg/dm²/day)
In nitric acid 24.1mdd (mg/dm²/day
In sulfuric acid 12.4mdd (mg/dm²/day
In oxalic acid 6.2mdd (mg/dm²/day
2) The values at pH=1 in the acids used were as follows:
In hydrochloric acid 11.7mdd (mg/dm²/day)
In nitric acid 7.0mdd (mg/dm²/day
In sulfuric acid 7.0mdd (mg/dm²/day
In oxalic acid 6.7mdd (mg/dm²/day
3) The anodic polarization curve of aluminum in hydrochloric acid showed little polarization. The current was produced at a potential slightly nobler than the spontaneous electrode potential. Pitting corrosion was produced on the electrode.
4) Limiting current appeared in the anodic polarization curves in the acids other than hydrochloric acid. It was due to the formation of oxide film on the surface of aluminum.
5) Cathodic polarization curves were varied according to the quality of aluminum and kind of acids. The reason would be due to the electronic conductivity of the films on the surface of cathode.
6) The corrosion current determined from the intersecting point of Tafel lines of anodic and cathodic polarization curves fairly corresponded with that calculated by the weight loss.

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This paper describes investigations concerning the effects of thiourea on various copper anodes in 0.5mol H₂SO₄ at 25°C.
The results obtained were as follows:
1) The anodic reaction of rolled and annealed coppers was more active than that of electrolytic and refined coppers when no thiourea was added. It was found that the cold rolling of copper was effective in preventing passivation.
2) The addition of thiourea promoted reaction in anodic polarization. However, thiourea acted as an inhibitor of anodic reaction in galvanostatic or potentiostatic electrolysis to promote passivation effect.
3) Cu and Cu-S-compounds were observed in slime in the active zone, but Cu and Cu₂O were observed in slime in the boundary zone by X-ray diffraction method.

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The formation and morphology of galvanically substituted Ag films, which had been deposited on Cu single-and poly-crystals from a solution containing silver cyanide and sodium cyanide, were examined by electron microscopy.
The results obtained were as follows:
1) In the early plating stage, the density of Ag micro-particles was about 1.5×10¹²cm^-2.
2) The primarily deposited Ag micro-particles cohered one another or individually grew up into insular crystals, which were further linked together to form network plate crystals.
3) No coherency was observed between the primary Ag microparticles and Cu planes. However, the difference in orientation between the both was gradually decreased with the increase of the plate crystals, and a stable coherency was observed when the crystals were completely grown up into network structure.
4) The coherency was as follows:
(001) Cu//(001) Ag [100]Cu//[100]Ag}……(1)
(110) Cu//(110)Ag [110]Cu//[110]Ag}……(2)
(111) Cu//(111)Ag [110]Cu//[110]Ag}……(3)
5) In the Ag plate crystals, there were found many micro-twins and stacking faults, which contributed to the relaxation of stress due to the misfit between the Ag films and Cu substrate.
6) When Cu was dipped in the B-2 solution (AgCN 7.5g/l, NaCN 30g/l) for a long time, there were observed particles of 0.5-2μ in size on the Ag Plate crystals. Some of the particles cohered one another to make up spheroidal crystals.

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Studies were made of the effects of copper and iron as impurities contained in cyanide baths for silver plating.
Measurements of cathodic polarization curves, absorption spectra, and electric conductivity revealed that copper and iron produced high stable cyan complex by the reaction with free potassium cyanate in the bath, by which the deposition potential of silver was made less noble.
The results of studies on electrodeposited silver by X-ray diffraction method and electron microscopy showed change in leveling degree and formation of coarser crystal particles with the increase of copper density.
Uneven brightness was produced by iron of lower than 0.1g/l in density; but, iron gave no orientation of crystals, and formation of coarse crystal particles and change in leveling degree were also observed with the change of iron density.

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