Gap and galvanic corrosion of stainless steel

You are interested in crevice and galvanic corrosion of stainless steels from the company — supplier Alekhlas? Here you will find the necessary information on the topic.

The essence of the phenomenon

When two different metal or alloy are immersed in a corrosive solution, each will develop a corrosion potential. If there are conditions for galvanic corrosion, the more noble metal will become the cathode and the more active metal anode. Between the anode and cathode can flow current. The corrosion rate of the anode in the working environment will be increased and the rate of corrosion of the cathode will decrease. Increased corrosion of the anode is called galvanic corrosion.

Galvanic corrosion is not always harmful, and is sometimes used to extend the lifetime of materials (i.e. zinc coatings on carbon steel and zinc anodes in water heaters).

Flow conditions of galvanic corrosion

For the occurrence of galvanic corrosion requires two metals with different corrosion potential and a conductive electrolyte solution. The electrolyte creates a conductive bridge. This can occur when there is constant immersion, condensation, rain, fog effects, or other sources of moisture connecting the two metals. If any of these elements is missing, galvanic corrosion does not occur.

When two different metals are joined together in the atmosphere or water, the likelihood of galvanic corrosion can be predicted, which is used in specialized applications, for example, when concrete is embedded dissimilar metals.

Supplier — the company Alekhlas — offers to purchase assortimente metal, made of different grades of stainless steels. Products can be purchased at a price formed on the basis of European and world standards. Possible, wholesale and retail, for regular customers a flexible system of discounts.

The resistance of stainless steels to crevice and galvanic corrosion

For stainless steels is important not only to their composition and type, but also the profile of the rental. In most applications, which combine dissimilar metals, to determine the position of the stainless steel should be used for passive (solid) core.

The effect of relative surface area

If the area of the cathode (noble metal) is very large, and the anode (active metal) is very small, the generated current will be very high and the anode will corrode quickly. For example, if the window frame is made of stainless steel and attached with screws carbon steel, the fasteners will corrode at an accelerated rate. On the contrary, if the window frame is made of carbon steel and fastened by stainless steel screws, galvanic corrosion is characterized by a very low intensity. A relatively small surface area of the fastener of stainless steel means that these items do not have a galvanic effect on the corrosion rate of the element of carbon steel.

You should avoid combinations of dissimilar metals in areas where moisture can accumulate and remain for a long time. When painted carbon steel and stainless steel are welded together, the welded joint should be painted.

Not all environments produce the same galvanic results. Studies have shown, in particular, that galvanic and crevice corrosion are not a problem between the stainless and carbon steel in concrete.

Supplier — the company Avecho offers various types of stainless steel domestic and foreign production. Products are offered at affordable prices from the manufacturer. Supplier guaranteed timely delivery at any address specified by the consumer.