Abstract-By the measurement of weight changes with time, the extents of corrosion on specimens of mild steel, medium carbon steel, brass and aluminum exposed to the laboratory atmosphere and 0.1M solutions of sodium chloride, ammonium hydroxide and hydrochloric acid were obtained. These solutions, respectively, represent salt, basic and acid environments that are usually encountered by the test metals in actual service. Corrosion -time graphs were then drawn for each exposure environment to facilitate the assessment of the relative aggressiveness of each environment on the test metals. A graphical illustration was further made to show the relative aggressiveness of the environments on any particular metal.Index Terms-Laboratory environments, mild steel, medium carbon steel, brass, aluminum.
I. INTRODUCTIONIn selecting a metal for a specific application, it is necessary to have a prior knowledge of its corrosion behavior in the particular environment. In some other circumstances, it may also be required to have a knowledge of the relative aggressiveness of different environments on a particular service metal; or of the relative aggressiveness of a particular environment on different metals. Such knowledge is important, for instance, in a situation where alternative metal containers are being contemplated to hold a particular corrosive liquid.In nearly neutral aqueous environments, the corrosion of metals is a result of the oxidation of the metal by a reaction which in its simplest form may be written as [1].Assuming the metal to be bivalent as in the case of iron, copper and zinc; or as in the case of a trivalent metal such as aluminum.It is well known that the susceptibility of a metal to electrochemical corrosion, to a large extent, depends on the metal's position in the electrochemical series; and when metals and their alloys are in service their relative corrosion behavior is usually predictable by recourse to the galvanic series relevant to the service environment. There is, thus, the While the galvanic series are useful in predicting the corrosion behavior of unprotected metals, several other factors come into play in determining actual corrosion patterns. Such factors include the metal's exact composition; its dimensional properties such as surface area, shape, and surface roughness index; and its surface temperature. The actual relative aggressiveness of different service environments on metals would therefore be known only through controlled experiments.In this paper, the relative extent of corrosion, after any given time of exposure of specimens of mild steel, medium carbon steel, brass and aluminum, in particular laboratory environments are assessed. The environments utilized are the laboratory atmosphere and 0.1M solutions of sodium chloride, ammonium hydroxide and hydrochloric acid. These solutions respectively represent salt, basic and acid environments that are usually encountered by the test materials in actual service.For the sake of achieving the desired control in experimentation, factors which...