抄録
The surfacial state of the lead coated steel by hot dipping and its coating mechanism are investigated. The author thought that it was an effective method both theoretically and practically to estimate the surfacial state of the specimen by measuring the electrode potential, however, it seemed to be much influenced by many factors. The results obtained are as follows:
1). The steel specimen is coated very nicely when dipped into the lead melt of a bit higher temperature than the melting point.
2). According to dipping time, the coating mechanism was found to be divided into two steps, namely the primary coating and the secondary coating, the former being made chiefly by the reaction of the used flux. The flux used works effectively at the beginning of coating reaction and the primary coating ends in two minutes. The thicker the specimen, the more excellently it is coated in the primary coating. The latter is made by direct intermetallic reaction requiring rather long dipping time, e. g., about five minutes.
3). If the flux is used in solution of SbCl3, the specimen had better be immersed into it for a short time at room temperature, but in that of ZnCl2, SnCl2 or NH4Cl at raised temperature, for which the treatment time is little responsible.
