The adhesiveness of metallized coating was determined by a tensile test method with reference to its absorbed energy.
The specimen consisted essentially of a shaft which was provided with a hole clear throngh its axis. A stud is fitted in this hole, with one end flush with the flat surface of the shaft which was one side of the sections.
Preparation was applied all over the flat surface of the shaft and hence to the end of the stud.
After bonding and spraying the stud was pulled out of the shaft in a testing machine.
It was found that the adhesiveness of metallized coating is given by W/π/4d²kg·m/cm², where W is absorbed energy by the specimen and its jig in kg·m and was determined by a load-elongation curve abtained by the testing machine, and d is a diameter of the end of the stud in cm.
The practical measurement performed by this method with d of 2.0, 1.0 and 0.5cm showed that the maximum value of the adhesiveness between a metallized coating of 13 Cr stainless steel (about 1.5mm thick) and the base metal of 0.2C mild steel prepared by spraying with molybdenum was about 0.8kg·m/cm², and mean value 0.33kg·m/cm² in any case of d.

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Micro-corrosion-o-scope is constructed for the purpose of observing the process of corrosion which occurs on the metal surface microscopically. This method is applied for such cases a water drop-metal surface system, gelatine drop-metal surface system, gelatine layer-metal surface system, etc. Treating the specimens electrographically, the corrosion proceeds rapidly. The initial anode position of mild steel surface prepared by dry polishing or that of crystal surface can be observed using pottasium ferricynide as an anodic indicator. The difference of adsorbing ability of crystals of mild steel surface is photographed too.

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Ferroxyl test has conventionally been adopted for testing electrodeposited nickel, but it is not always good method, because ferroxyl test solution disolves nickel. The mechanism of the ferroxyl test solution to dissolve plated nickel is not known. Therefore, many experiments to make the mechanism clear were carried out.
Result: As shown in the following equations, K₃Fe (CN)₆ acts as an oxidizing agent and under the presence of NaCl, dissolves the plated nickel to form the ferrocyanide and ferricyanide.
2Fe(CN)₆^---→2Fe(CN)₆⁼⁼
Ni →Ni⁺⁺
The oxidizing action of K₃Fe(CN)₆ in this case is more vigorous than dissolved oxygen in the testing solution.

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Electropolishing of carbon steel has little been used commercially due to the variation in composition and surface condition of heat-treatment. The author, therefore, as fundamental experiment for its industrial application, investigated the polishing effect of various carbon steels which heat-treated under various conditions, observing the anodic current density-bath voltage curves obtained in perchloric acid type, phosphoric acid-oxalic acid type and phosphoric acid-potassium dichromate type bathes.
As the exsistance of different potentials between ferrite and cementite deteriorates the polishing effect, the result is the worst for the steel of heterogeous structure such an pearite. The more homogeneous becomes the structure after cheat-treatment like martensite, the more effective is the electropolithing.

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Mechanism of gyro-finishing was investigated with a drum of 400mm diameter and less than 300r.p.m., in which cylinder-shaped steel, brass, and aluminium alloy were polished.
The result is as follows:
(1) The smaller the specific gravity of the media, the more uniform is the shape of the mass.
(2) The best polishing effect is obtained when 300c.c. of water is added to 1, 000c.c. of media.
(3) The lower the hardness of the metal is, the sooner is the polishing speed.
(4) Special space of the work is abrased more heavily by unbalance of the mass and side pressure of the drum wall.
(5) The polishing is done by the friction between media and the work, but not by collision of media with the work.

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Some significant factors for chemical corrosion of lead-covered telegraphic cable were studied experimentally from the viewpoint of electrochemistry. Corrosion and polarization potential of the lead which is immersed in manhole water or other various corrosive media were measured.
(1) The chemical species (especially anionic) contained in manhole water seem to have something to do with the potential behavioors, and some of them tend to form the protective films. Therefore, it seems more important that this factor should be considered chemically than electrolytically.
(2) The heterogeneous potential distribution on the surface, caused by the ununiformities in micro or macro structures and in their surface differential aerations, were observed. The maximum difference of potential caused by local cell was about 100mV, which was enough to induce the local current leading to anodic corrosion. For example, it appears between the fresh surface and oxidized film. But no anodic acceleration occurred at the contact of lead-cover with the steel pipe used for protection of cables.
(3) From the results above mentioned, some practical informations for preventing corrosion on the lead are proposed concerning the suitable conditions and materials of cable construction.

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