Acid-resistant and corrosion-resistant steels

• 14.10.2019
• 6112

Main advantage of stainless steel is the resistance against the corrosion. In view of this feature, the alloys are used in different fields. Corrosion-resistant steels are able to be seen in the manufacturing household appliances and tools, medical equipment and tools, in car manufacturing and ship building, construction and other fields. For the first time, the steel was considered in 1913; and there has been great demand for stainless rolled metal products up to date.

Alloy characteristics

Corrosion-resistant or stainless alloys are the metal products that are resistant against the influence of negative environmental factors. They are based on the iron the features of which are changed by means of the carbon. Alloy is able to be additionally enriched with valuable elements, for example, with chromium that increase the resistance against the moisture influence. Only 10,5% is enough for the improvement of some features:

• the processing by cold moulding method is simplified;
• the durability is increased;
• shelf life of the products, made of corrosion-resistant steels is increased;
• more reliable junctures are formed when the elements are jointed by the welding;
• the metal features are saved even during intensive use;
• aesthetic attraction is not lost.

By means of the chromium in the alloy, oxide coating is formed on the surface. Namely this coating prevents intercrystallite corrosion. Let us consider this process in details.

Corrosion: how to prevent the failure of metal

The iron is influenced by the environment. Moisture and aggressive environments facilitate the removing intercrystallite grid. Surface failures is called corrosion. In order to stop or avoid in common this process, the oxide coating is formed on external layer. However, there is no enough of this coating, that is why intercrystallite corrosion of stainless steels occurs very intensively.

Chemical influence of the environment is able to be stopped by means of the additives, which increase the resistance of the alloy. Application of special elements in the steel rapidly improves the features of the substance. Such alloys are influenced by the moisture in the air, aggressive acids, slats and alkalis fewer.

Details of the types of stainless steel

There are more than 250 stainless steel grades. Their main differences are the absence in the crystal grid of the elements determining main features. In addition to chromium, such additives as Ni, Mo, Co, Ti, No etc. are used. Difference in features and fields of use depends not only on the additive name, but on its percentage. In addition to iron and auxiliary elements, there is the carbon in stainless metals. It provides high strength and durability for finished metal.

Let us consider main types in details. All the types of stainless steel are able to be divided into several groups:

• chrome steel. This is the alloys containing the chromium in amount of more than 20%. The metals with ferrite structure became widespread in heavy industry. They are used for the manufacturing heating and other big equipment. The alloys with high chromium content are differ in high resistance against corrosion and magnetizing ability;
• grades austenitic internal structure.  This is the alloys containing the chromium and nickel. Their amount is no less than 33%. These metals are in high demand in all the fields. They differ in corrosion resistance and attractive appearance;
• metals with martensite and ferrite-martensite structure or corrosion-resistant steel. It has the carbon in high amount that increase the wear resistance of the alloy. Such a content provides maximum durability and long life. In view of this acid-resistant steel is used not only in the fields of national economy; it is able to contact with aggressive environments; the equipment made of this metal is used in high temperatures;
• stainless steel with combined structure. This is the metals with austenitic-ferrite or austenitic-martensite structure. Innovative solution that combines the advantages of other types.

Acid-resistant stainless steel and other grades has excellent composition. Namely this feature determines technical and exploitation features of the metals. All of them are successfully used in modern industry. One of the main suppliers of high-quality alloys is "Orinnoks" company. It is the leader among the metal traders in the RF. You can order the product and get details about the metals on the website.