The effect of ammonium salt, sulfate, potassium salt, and sodium salt on the electrodeposition of the tungsten alloys from tartrate and citrate plating bath was studied.
The cathode current efficiency and the tungsten content of the deposits from sodium tartrate bath were similar to those of the deposition from sodium citrate bath.
It was found that, with the addition of ammonium salt to the tartrate bath, the current efficiency was increased remarkably as compared with the results in the case of citrate bath, and the highest current efficiency was obtained at the molar ratio of the ammonium salt to the tartrate was 1:1.
However, any effect of sulfate, potassium and sodium salts on the electrodeposition of tungsten alloys in the tartrate plating bath was not found.
When the hydrazine sulfate was added to the tartrate bath, as in the case of ammonium salt addition, the current efficiency was increased remarkably as compared with those in citrate bath.

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It is difficult to find out such a suitable rod for either gas or electric welding of two “Alumers (hot-dipped aluminum coated steel)”, as not to cause any cut-off defect in the Al-Fe alloy layer around the welded border line.
Therefore, V-shape cut off is usually made first along the welding line of two Alumers, which, then, can be welded with ordinary welding rod, and this welded line is finished, if necessary, by covering with thin layer of special steel welding rod. In Fig. 1, the cut-off defect can clearly be seen in the Al-Fe alloy layer, which has been one of the gravest defects of Alumer, unsolved since it turned up in the Japanese industry.
A series of experiments, therefore, was carried out to find out a suitable rod especially for electric welding of “Alumer”, and the result was as follows:
(1) By using the suitable flux, it is possible to weld Alumers together with the Al or Al-alloy welding rod, and stable Al-Fe alloy layer can be obtained.
(2) With the fluxes of main ingredients of KCl, NaCl, and AlE₃, and addition of small amount of K₂SO₄ and NH₄Cl as ionization medium, the weldability is much improved.
(3) With the rods of Al-Si (Si 11%) alloy as core metal, more stable layer is obtained, and the weldability also becomes better.
(4) It is necessary to use D. C. welding of reversed polarity arc.
(5) Comparing high temperature oxidation resistivity, the welding with Al-Si rod is superior to that with the stainless steel rod.

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Resistivity to oxidation and growth of hot-dipped aluminium coated cast iron (gray and white) of various compositions and structures were investigated with specimens heated at 900°C for 3 hours.
The result was as follows:
1) The resistivity to oxidation and growth at high temperature of hot-dipped aluminium coated gray cast iron was much improved as compared with the uncoated mother metal.
2) Those of gray cast iron was effective in inverse proportion to C and Si contents in the mother metal.
3) Those of white cast iron was remarkably improved.
The smaller the amount of C and Si contents in mother metal, the better.

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The relation between the nickel plating speed and the concentration of ammonia in ammoniacal electroless nickel plating solution containing 0.1M nickel chloride was studied and the highest plating speed was obtained at the ammonia concentration of 0.2-0.3M or at the pH of 8.3-8.5.
On the other hand, a curve of nickel deposition potentials at various pH values of the same plating solution was plotted, and it was revealed that a maximum point appeared on the curve when the nickel was in the state of diammino-citrato-nickel complex ion [Ni(Cit)(OH₂)(NH₃)₂]^-.

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