The object of this examination was to find the possibility that the phosphate frit melting at a low temperature might be glazed on the aluminized steel plates. Tests were made especially on the pre-treatment of aluminized steel plates, adjustment of expansion coefficients, and adherence of the frit.
1) It was made clear that the sodium perborate method (T. Yamada and S. Tomino, J. Ceram. Assoc. Japan, 67 (1) 88 (1959)) was as excellent for the surface treatment of aluminized steel plates as for the pre-treatment of aluminized plates in aluminum enamelling.
2) When it was glazed on the steel plate, the frit was cracked on the surface. It was clear that it arose from the fact that the expansion coefficient of the frit was larger than that of the aluminized steel plate. Adjustment of this coefficient was effected by adding bentonite, TiO₂, SnO₂, and Al₂O₃. Optimum amount of addition was 0.1% bentonite, over 1% TiO₂, 0.5-1% SnO₂, or 2-3% Al₂O₃ respectively.
3) Good adherence of the adjusted frit to the aluminized steel plate was ascertained by the bending test.

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The corrosion rate (C. R.) of some metallic and nonmetallic materials dipped in the condensed phosphoric acid (CPA) which contains 72-85% of P₂O₅, with and without agitation were observed. The results obtained are as follows:
1) The C. R. of silica glass is small in the law temperature range, but obviously increases above 200°C.
2) The impervious graphites in which organic resins are permeated, show unstable C. R, . sometimes they show the negative C. R.
3) The C. R. of Hastelloy B dipped in CPA for a long time is smaller than that in the initial time.
4) The C. R. of Ta is the smallest of all materials, and its allowable temperature is 200°C. Its anticorrosivity is not influenced by the agitation of corrosive media.
Therefore it was confirmed that Ta is the most useful constraction material for the CPA plant.

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Effect of the dispersing agent to bright acid stannous sulfate bath containing reaction products of aldehyde and amine, cresolsulfonic acid and formaldehyde was studied by Hull cell test and cathode polarization measurment.
In the case of using the sodiume n-octyl sulfate in the bath, immediate effect was negligible, but after aging brightening actions were observed.
On the other hand, when polyethylen glycol nonylphenyl ether or polyethylen glycol iso-octyl ether, which have suitable HLB, were used in the bath, a clean bright deposit over most of its length of Hull cell panel at 1A was obtained without aging.
The ether type nonionic surface activating agents, easily procurable from the free market, are stable in the solution that can advantageously be used immediately without aging. This might be accounted for the fact that the activating agents of this type seem to form stable micells immediately with brightener and to act as good carrier of it.
Cresolsulfonic acid and formaldehyde were effective to widen bright deposit area. The highest orientation of crystals of tin was observed by X-ray diffraction in the bright deposit from these bath, compared with those from other baths. These type activating agents could not be used with wood tar, because they broke up unnecessary components of the wood tar and dispersed it in the bath.

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