| Abstract: | The electrode behaviour of zinc and iron in calcium hydroxide solutions and in mortar The behaviour of zinc (fine zinc and metallurgical zinc) and of unalloyed steel in a saturated calcium hydroxide solution and in mortar has been the subject of electrode-kinetic investigations. The observations showed that the behaviour of fine zinc, metallurgical zinc and galvanized steel is more or less identical, and that even the mortar coating has little effect on the electrode behaviour. It is found that - (a) zinc is passivated by a zinc oxide layer;
- (b) the potential of a short-circuit cell consisting passive zinc and iron becomes so negative that hydrogen is developed at the iron at an appreciable rate;
- (c) the passivity Of the zinc in a solution containing chloride is removed at a much higher chloride concentration than that of steel.
In the case of a galvanized electrode with an electrolytically dissolved layer of pure zinc, the current/potential characteristic was similar to that of the passive iron. |
