Rapid progress has been made lately in the techniques of atmosphere controlling and, the desire for operating bright quenching has become markedly extensive, and accordingly the necessity has arisen for investigation of such an oil named “bright quenching oil” that can be effective for working bright quenching.
Hence, the authors studied the properties or compositions of oil which are desired for bright quenching.
Fatty oil gives generally good brightness and solvent refined (Duo-Sol method) mineral oil also suitable for bright quenching giving good brightness. With incrreasing time of air blowing into oil by means of Indiana method, brightness decreases and is ultimately spoiled entirely due to the scorching of sludge on the surface of steel. Water and oxygen contained in oil are considerably harmful for brightness.

抄録全体を表示

We compared the corrosion resistance of aluminized steel with that of galvanized steel in acidic, neutral and alkaline solutions with pH value of 2-14 range at room temperature and 60°C.
At room temperature, aluminized steel has remarkably superior corrosion resistance in the neutral and acidic solutions with pH less than 8. Especially, this steel is not entirely attacked by immersion for more than one month in the solutions with pH 6-8, and maintains its initial metallic luster. But this steel is attacked remarkably by alkaline solutions with pH value of more than 8.5. Galvanized steel has rather superior corrosion resistance in alkaline solutions of narrow pH value range only from 11 to 13. The surface of this steel is easily attacked even by neutral solution and its color changes to black, of course, it is more easily attacked in the acidic solutions with pH value of less than 7.
At 60°C, aluminized steel shows the weight loss by corrosion as follows; 2g/m²/day in neutral solution, 20g/m²/day in pH 3 solution and 60g/m²/day in pH 2 solution. But the corrosion resistance of aluminized steel in neutral and acidic solution at 60°C is still more superior to that of galvanized steel in the same solutions than at room temperature. Galvanized steel shows at 60°C good resistance only in the solution with pH value of 12. When the pH value of the solution is over 12, with even its slight change, the corrosion resistance of this steel becomes worse remarkably, and the steel is severely attacked at the same temperature.

抄録全体を表示

We obtained good results of the chemical test on coatings of galvanized steel by antimony trichloride and copper sulphate, because zinc coatings by pickling of before treatment has the smoothest and most suitable adhesivity of zinc.
We investigated the properties of coatings of galvanized steel which were treated by shot-blasting and sand-blasting for descaling of steel.
Descaling by blasting methods are speedier and healthier than pickling, but zinc coatings after these treatment are not smooth and deposit metallic copper more quickly on the surface of steel when immersed in the copper sulphate solution, and also its microstructre are disorder and rough.
Therefore, we can't recommend these blasting methods for pretreatment on golvanizing.

抄録全体を表示

As the first step of researches on the mechanism of electro-deposit on anodic coatings on aluminum, aluminum-plates were treated in three different anodizing baths sulphuric acid, oxalic acid and phosphoric acid the effects of thus formed coatings on electro-deposit were investigated. The results were as follow:
The electro-deposit on the coating of sulphuric acid bath was inferior and that of oxalic acid bath in low voltage anodizing was rather good but became inferior as the voltage increased. The maximam deposit was attained on the coating of phosphoric acid bath and the deposit was of finer metal grains.

抄録全体を表示

The electro-plating of aluminum and its alloy has been so far considered to be hard. To get over this difficulty, the two studies were carried out, one of which was the treatment by conc. HNO₃, and the other zincate. In this study, after reviewing the above-mentioned methods, the author found out that the former was better when treated for a long time than for a short time, and the manganate processes, was also as good as in the case of chromate. The same result was also obtained by treating after the electro-polishing.

抄録全体を表示

We investigated the microphotographical figure, rate of reflecting power of light and corrosion registance of aluminium powder contained in aluminium paste (made in England, Germany and Japan), and the following results were obtained.
Small amount of massive particles were observed among the fine leaflike aluminium powder.
The ratio of reflection of “Alpaste” (made in England) was of highest value. By the corrosion test measuring dissolving rate of powder in 5% hydrochloric acid solution, the powder made in Japan was excellent next came that of Germany and then that of England. However, the effect of organic solvent existed in the paste and size of aluminium powder were out of consideration.

抄録全体を表示

Four Kinds of sample of paints pigmented with “Alpaste” have been prepared by the use of alkyd-resin varnish and Durabond varnish as vehicle, and the performance tests of adhesion, exterior durability, impact resistance and sea-water resistance of their films coated on metals have been carried out in order to examine how durable they are as corrosion-resistance coatings for metals.

抄録全体を表示