The object of the work was to look into the behavior of the stress corrosion cracking of straight brass containing Zinc 20 to 50%, and the influence of stress upon the electrode potential of 70/30 brass in aqua ammonia.
It was demonstrated that the alloys containing Zinc 35 to 40% had the lowest resistance in aqua ammonia cracking, and that the alloys containing until Zn 26% were intergranular cracking, while the brass over Zn 30% transcrystalline cracking.
There was the following relation between the rupture time (P) and the magnitude of stress (σ), σ=CPⁿ, and the same for the concentration of NH₃, too.
The potential-time curves of stressed brass, compared with the non-stressed specimen, have shown the less noble value immediately after the corrosive agent was added, and then, however, the potential have rapidly changed to more noble in aqua ammonia.
The electrode potential of stressed brass, as expected, was less noble value, compared with the nonstressed specimen in 3% NaCl solution.

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Secondary-amine-type inhibitors, prepared by reacting 1mol secondary-amine with 1mol corresponding acid at elevated temp., were tested. When dully dispersed in corrosive media, they can be more rapidly adsorbed onto metal surfaces than those primary-amine-type inhibitors described in our prior essays. In severely corrosive media, we can get better inhibition with them. Among C₈-C₁₈ amine-type inhibitors higher ones are more protective, when their harder dispersion are released.

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