抄録
In the last paper, the author reported a new method of iron electrolytic refining, using an electrolytic bath which contained a small amount of surface-active-agent. In the present paper, some investigations on the electrodeposits obtained by this new method, are described with refe-rences to the deposits by traditional methods. Microscopic and veisual observations, the hardness tests and examinations on the throwing power were carried out. The following facts had been observed as the effects of surface-active-agents which were added to electrolytic baths.
1) The fibrous structure which was found in the metallographic structures of almost every electrodeposited metal, tended to be a meshy structure.
2) The hardness numbers were various according to the addition amounts of surface-active-agents. A little lower number was found in the case of the addition of a small amount than in the case of no addition. But a little higher number was found in the case of the addition of an excessive amount, which might be caused by includig the molecules of surface-active-agents to the crystal structure and this might be subjected to internal stress.
3) The operation ranges of current-density, temperature and concentration of hydrogen ions, in which such defects as pits, crocks and uneveness appeared on the surfaces of electrodeposits, were reduced. The operation range in which the pitless surface appeared, extended especially.
4) The throwing power seemed to be increased.
Therefore, the new method of iron electrolytic refining which had been mentioned in the last paper, should be suitable for practical use.
