The means to introduce the reaction of C and O in the steel bath in order to let C display its role is performed by oring. That is, in the open hearth process, the protection of oxydation is attained by the vigorous boiling introduced with ore addition. Here is the unusual problem of decarbarisation reaction in steel making. This is analysed in detail in this report.

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On the acidpickling of the medium carbon low alloy steels by the dilute sulphuric acid solution saturated with FeS, we can always find the flake-like defects on the fracture of tensile and bending test piece. The experiments with this phenomenon are summerized as follows:
(1) The appearance of this defect is similar to the normal flake of the alloy steels but smaller than the latter.
(2) The tensile quantities vary with its heat treatment. If the test piece be quenched and tempered with comparatively high temperature, tha defects will appear during the tensile test, but if the test piece be quenched only or quenched and tempered with the low temperature, the defects must appear during the pickling.
(3) From the results of the bending test and the pickling of the quenched test piece it will be assumed that the defect may occure by the co-operation of the stress by the supersaturated hydrogen and the other tensile stress.
(4) The flake-like defects may occure at the definite point on the test piece, because we can recognize this point during the tension test before this test piece be broken and if the acid pickling be prolonged, this part will be corroded more strongly than the other part.

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Investigations have been made by the author on the relation between the machinability and the angles of chips of 18-4-1 standard high speed steel.
Influence of the yiscosity and cooling velocity of liquids for cutting metals on the abrasion and machinability of the standard high speed steel have been studied.

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Made studies on some conditions in heat treatment (heating velocity, heat retaining time and cooling velocity) on composition of white cast iron, and on the effect of special elements, to secure the perfect pearlitic structure. The results obtained were as follows:-
(1) The time of graphitization at 900°C being shortened by increasing Si contents;
(2) Impossible to produce perfect pearlitic structure by increasing Si contents;
(3) Heat retaining time, cooling and heating velocities conspicuously effect the production of perfect pearlitic structure;
(4) Obtained the diagram of relation betwen chemical composition and heat treatment condition;
(5) The size of temper carbon proved to be big when heating velocity increased;
(6) Justified the effects of special elements (Mn, S, Cr, Mo, V, Ni, Cu, Al etc);
(7) Mn 0·7-1·25% is most effective for elimination of free ferrite.

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Spiral carbon vacuum furnace have been completed, which will satisfy most of the conditions required as such in the vacuum fusion, one of the metlbods of gas analysis in steel. 2000° Cent., could be attained in it with the power of 2·4K. W.
The following are investigated with this vacuum furnace:
1. The effects on measured values of various elements, which evaporating in the oxygen analysis of test pieces and adhering to the inner walls of reccptacles.
2. The results of analyses of various kinds of graphite crucibles.
3. Tne rate of deoxidation due to temperatures of each oxide and test pieces containing the oxide, to determine the adaptability of the fractional vacuum extraction method.
4. The manufacture of rapid analysis apparatus to complete the analysis within 40 minutes after preparing samples from molten steel, which has proved possible.

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