During the use of a shaving blade, there are two main processes which cause the deterioration of the original condition, these are:                Oxidation, and        Wear.        
Oxidation or corrosion is understood to be the destruction or deterioration of a material due to the reaction with the environment. Chemically, oxidation consists of substances in a suitable oxidating atmosphere accepting an electron and they are reduced. The electron comes from atoms of the metal or from other items in the oxidating atmosphere. As the process of oxidation continues, the metal or item is degraded to the point that it can no longer be used for its original purpose.
To cease the process of corrosion, it is fundamental to stop the metal atoms loss of electrons from other atoms or ions. Corrosion is an electrochemical process, in as much as the chemical destruction accompanies the circulation of electricity.
The corrosive process, specifically as it relates to iron, is described by the reaction opposite to the one of reduction, in which we have following half reaction:Fe2+→2e−Fe.The value of the potential of reduction (E0) for this half reaction is:E0=−0.44 volts.
The one that can be carried out towards the left if it is connected with another one whose value of potential of reduction of average cell is greater. This happens frequently in environmental conditions, since two of these reactions are those of reduction of protons and oxygen, to produce water and hydroxyl ion, respectively.
According to this we have the following half reactions with its respective values of potential of reduction:O2+4H+4e−2H2O E0 reduction=1.23 volts2H2O+2e−H2+2OH−E0 reduction=−0.42 volts.
Both reactions connected with those of iron spontaneously give rise to the oxidation of the metal. In this way, when there is enough water, oxygen and acid, a saline atmosphere will cause the iron objects to oxidize little by little. In this way, the iron oxidation and oxygen is reduced. The standard potential for the cell is:E0 cell=+0.44 volts+1.23 volts=1.067 volts.The process is spontaneous. The complete reaction is:Fe+O2+4H+Fe2++2H2O.
Some suggest that the definition of corrosion should be restricted to metals. Nevertheless, corrosion engineers should frequently consider metals and non metals for the solution of a given problem. To illustrate, deterioration of a painting by the action of ultra-violet rays, chemically is fusion of the internal coatings, and the attack of a solid metal by another fused material is considered a phenomenon of corrosion.
On the other hand, it is known that all the metals and alloys are susceptible to corrosion. Nevertheless, all the materials are not corroded by effect of such elements. For example, gold is corroded in mercury at room temperature, iron is not corroded as well by mercury, but it oxidizes in environmental conditions, as we have already seen.
The processes of corrosion is classified depending on the means in which they are developed or its morphology, for example, it depends on the environment or atmosphere can be classified as:
A. Chemically: one studies under this denomination those cases wherein the metal reacts with non ionic means (for example: oxidation in air at high temperature)
B. Electrochemically: from the point of view of the metallic ion partition, all the processes of corrosion are electrochemical. Nevertheless, it is usual to designate corrosion as electrochemical as it implies a simultaneous transport of electricity through an electrolyte. To this important group belongs corrosion in saline solution and seawater, atmospheric corrosion, ground corrosion and the like.
Whereas the classification of the processes of corrosion depends on the form and is useful when the attack mechanisms are studied, it is very advisable when it is wanted to evaluate the damage produced by corrosion.
On the other hand, corrosion can cause diverse loss for industry, direct or indirect that is translated in replacement of corroded equipment, redesign of equipment in agreement with the type of corrosion, preventive maintenance, shutdown of equipment, product contamination, loss of product, loss of effectiveness, security, health, cost of the natural resources and appearance.
Due to these important consequences, many different means have been created to prevent it. In effect, the first methods consisted of applying a covering, for example, a painting to the metal object that is desired to be protected. In this way, the metal is protected from contact with the oxidant atmosphere preventing this form of corrosion. Nevertheless, after a time, this covering wears out and the process of corrosion begins. Therefore, the only way to prevent this corrosion from beginning again was to apply this covering again. This process has the disadvantage of being relatively expensive and impracticable, for example, in the case of manufacture of automobiles the covering would have to be applied to each part of separately and, once assembled, touched up. In the case of submarine pipes, the touch up process is not possible. This method is not viable.
Another process to prevent oxidation includes a cathodic system of protection. Where the protected metal objects are changed into cathodes of a electric circuit, the cathode or metal that is desired to be protected and an anode connects to a electric energy source, and the circuit is completed with a watery solution. Where the electric energy provides electrons, in such a way that the electron donation of the metal is reduced to protect the metal.
U.S. Pat. No. 3,242,064 discloses the cathodic protection through pulses of current applied to the surface of the metal, where the pulses are activated by variations in the water that surrounds the metal that is desired to be protected. U.S. Pat. No. 3,692,650 describes a cathode protection system useful to apply to pipes buried in the ground. The system uses pulses of DC voltage.
U.S. Pat. No. 4,767,512 discloses a method to prevent corrosion with objects without the necessity of submerging them in a conductive medium. An electronic current is forced within the metal object since the metal is treated like a negative plate of a condenser. This is reached by connecting the condenser between the metal object and the medium to provide energy pulses. In one embodiment, Cowatch describes a device in which a voltage of 5,000 to 6,000 volts DC is applied to the positive plate of the condenser.
That invention presents security problems since applying a voltage of that magnitude to a plate that possibly can make contact with humans or animals can cause important health consequences.