The corrosion of metals and alloys, especially, iron and Steel have been much studied during past years. However, the investigations on galvanic corrosion or contact corrosion of iron and steel have been carried out comparatively in small circles and very few reports were published. The auther has investigated the influences of chemical composition and micro-structure upon the galvanic corrosion of cast iron specimens, which were immersed in 3% NaCl solution touching with each other. By these contact corrosion tests very small differences of electrolytic solution pressure of cast iron have been recognized clearly, i, e.T.C and Si, by their graphitizing influences, increase solution pressure, while Mn, Cr, Ni, or Cu, decrease it.
High-grade cast iron (low carbon, low silicon and high manganese, furthermore, containing Ni, or Cr, ) therefore, will be retarded its corrosion speed by the contact of common cast iron, (higher carbon and silicon). After the completion of graphitic corrosion of common cast iron, however, both corrosion speeds change rapidly, for example, increasing galvanic corrosion of high grade cast iron. The amounts of graphitic corrosion of cast iron specimen will differ by its composition and micro-structure, therefore, by the ingenious selection of these factors, galvanic corrosion of main parts of marine engine will be much more retarded.
The investigations of such a practical application will nextly be reported.

View full abstract

The writer investigated the viscosity change of acid and basic open-hearth slags during the refining period, with measuring apparatus for viscosity based on the rotating cylinder method.
In the oxidation period the viscosity of the slag is small because of the addition of metallic oxides, such as iron ore, scale, and fluorspar. But in the equilibrium period the viscosity of the slag becomes gradually thicker by increasing the concentration of acidity or basicity, the acid or basic contents being absorbed from furnace banks.

View full abstract

Railway rolling stocks have been recently much increased in volume, weight and speed. These result to render severe service to the materials used in this field, and many papers referring to these materials, esfecially to steels, have been published in and abroad. But it seems to be less progressive, because the railway rolling stocks have the proper object of the safety and economical transferring Steels for this object must be anti-corrosive and anti-abrasive, and have easy workability, weldability, and moreover special properties. In this paper, constructural steels copperbearing steels, steels for boilers, spring steels and othar steels are explained.

View full abstract

The best molding sands available have usually been found only by a lengthy process of trial and error, but rarely by any scientific, espcially geological basis.
Of course the desiderata in prospecting for molding sands available is firstly to investigate the properties of them, i.e., the granularity of sands and the properties of bonding part as well as sand part which the writer has already looked into in the previous reports.
In this report, the geological origin and mode of occurence of molding sands of Japan were investigated by the mineral composition and the geological literature of the region of the product.
Then, an attempt was made to acquire the following desiderata in prospecting for molding sands in Japan by the collected data in this time:
(1) The most part of molding sand deposits in Japan are terrase deposits in the lower reaches of river (along present or abandoned lines of drainage) or marine deposits.
(2) They are, also, of diluvial or older alluvial age.
(3) The original rocks which are deemed to have furnished the best molding sands are: (a) quartz diorite, (b) plagio-liparite, (c) granite (in this case the acidic feldspar is required to be almost kaolinized), (d) sandstone (its mineral composition must be special and suitable for molding sands.)

View full abstract