Corrosion resistance of stainless steel
Are you interested in the corrosion resistance of stainless steels from the supplier AvecGlob? Here you will find the necessary information on this topic.
Basics of corrosion resistance of stainless steels
Carbon steel suffer from «general» corrosion, when large areas of the surface are affected. Stainless steel in the passive state is usually protected from this form of attack, however, local forms of attack can occur and lead to corrosion problems.
Therefore, the evaluation of corrosion resistance in any particular medium is usually associated with consideration of specific corrosion mechanisms. These mechanisms are as follows:
Surface corrosion;
Pitting corrosion;
Intergranular (or intergranular) corrosion;
Corrosion of mechanical stress;
Electrochemical (galvanic) corrosion.
In the course of corrosion processes, an erosion mechanism arises that is accompanied by fatigue of the material: with repeated but non-critical loads, the load-bearing capacity of the metal structure gradually decreases.
Localized corrosion is often associated with chloride ions in aqueous media. Acidic conditions (low pH) and increased temperature contribute to localized mechanisms of cleavage and pitting. The addition of tensile stresses, regardless of whether their loading is applied externally, or from internal residual stresses, provides conditions for stress corrosion cracking.
All these mechanisms are associated with localized destruction of the surface protective layer of the metal. Good oxygen supply to all steel surfaces is necessary to maintain the passive layer, but higher levels of chromium, nickel, molybdenum and nitrogen help in their individual ways of preventing these forms of attack.
Supplier — AvekGlob company — offers to buy a range of rolled metal products, made of different grades of stainless steels. Products can be bought at a price formed on the basis of European and world standards. Implementation is possible in bulk and retail, for regular customers, a flexible system of discounts operates.
Stability of stainless steels to local corrosion forms
As a rule, the increased corrosion resistance can be evaluated depending on the class of stainless steel. Increasing the chromium content from 11 to 17% by adding nickel to the chemical composition, it is possible to modify the passive layer and give it additional resistance to external corrosion effects.
Additional doping with molybdenum reduces the effectiveness of chloride ions when the passive layer is localized. With the combined action of chromium, nickel and molybdenum, the complex surface protection against corrosion is provided.
Even greater corrosion resistance has duplex stainless steels. They are specially designed to combat surface corrosion by «balancing» the structure to increase its strength, but the combined effect of bound nitrogen and molybdenum also increases the resistance of pitting and stress cracking.
Supplier — AvekGlob Company — offers various types of rolled products from stainless steel of domestic and foreign production. The products are offered at affordable prices from the manufacturer. The supplier guarantees the timely delivery of products to any address specified by the consumer.