No abstract

No abstract

The degree of corrosive destruction of m e c h a n i c a l equipment depends primarily on whether it is immersed in water, in a zone of variable water level, or in air. In the first case the chemical composition of the water, its oxygen content, and the development of microorganisms are very important. Corrosion of mechanical equipment in water is electrochemical, therefore, its activity is affected by electrical currents both of a galvanic origin and those arising from direct-current external sources. The designs of individual components of mechanical equipment which were developed without consideration of the need for corrosion protection, and, urtfortunately, such practices are still found, hamper the accomplishment of needed protective measures and sometimes even accelerate corrosion. The assertion is quite valid that corrosion protection of metal structures begins on the drawing board. This is especially true for mechanical equip~nent operating in water, the rate of corrosion processes in which is many times greater than in air. The sum of the indicated factors causes uneven corrosion in the form of conical growths on the machinery surface, under which are pits several millimeters deep.