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Sorts of Steel

Almost all of our produce is made out of steel. Based on the customer's choice we use carbon steel with various anti-corrosion coatings or stainless steel.

On average, 10% of our products are made of carbon steel and 90% of stainless steel. These numbers are shaped by the requirements of modern technological industrial processes. For instance, food and chemical industries use stainless steel only. Microelectronics, oil processing and car manufacture industries all have technological lines fully made of stainless steel for the following reasons. Stainless steel is resistive to high temperatures, corrosive mediums and severe mechanical wearing. Stainless steel is absolutely irreplaceable in a large variety of technological processes.

Combinations of additives give stainless steels various chemical and physical properties. The number of brands of stainless steels is vast! The main brands of stainless steel that PMP Ventilacia uses for manufacturing products are presented below.

AISI-304 (08Х18Н10) - Austenitic steel with low carbon content, acid-resistant, can withstand short-term heating up to 900 ° C. It is the most versatile and used steel. It is used to produce chimneys and air ducts, equipment for chemical, food, pharmaceutical and cryogenic industries, cutlery and dishes, equipment for yachts and ships. It is also used to create equipment for production, storage and transportation of milk, beer, wine and other beverages, as well as various chemical solutions. It is used to make pipes for various purposes, architectural elements and decorations or other metal structures.

AISI-321 (12Х18Н10Т) - Austenitic, corrosion-resistant, heat-resistant. Details made of it are work at temperatures in a range from -196 ºС to 600 ºС. In diluted acids and corrosive environments it resists temperatures up to +350 ºС. This steel also allows work in solutions of salts and bases. It is used to produce equipment for chemical, food, pharmaceutical and cryogenic industries. It is also used to create equipment for  production, storage and transportation of food products, as well as chemical reagents. This steel is very useful for details of stove fittings, heat exchangers and muffles.

AISI-316 (08Х17Н14М2) - Austenitic steel. This brand is an improved version of AISI-304 with a molybdenum additive. It has increased resistance to corrosive media, which gives it high resistance to corrosion in areas near the weld. It is used to produce containers for corrosive liquids storage. It is also widely used to create specialized industrial equipment in chemical, food, paper-cellulose, mining, pharmaceutical and petrochemical industries. This steel also serves well in architectural parts located in highly corrosive environments.

The main additive in stainless steel is chromium (Cr). Reacting with oxygen, a thin (130 angstroms), but very strong layer of chromium oxide (CrO) is formed on the surface of the steel. This natural chromium oxide coating is the key component that makes this stainless steel resistive to corrosion. The greater the percentage of chromium alloy is, the more resistant the steel is to oxidants.

For instance, if the percent composition of chrome is 12%, then the stainless steel is only resistant to weathering. If the percent composition of chrome is 17%, then the stainless steel is also resistant to nitric acid. For extra resistance to stronger oxidants, parts of nickel (Ni), molybdenum (Mo), copper (Cu) and titan (Ti) are added to the alloy.

The name of each stainless steel is given in two styles most widely used in Russia. The first one is in the AISI (American Iron and Steel Institute) format, while the second one is in Russian standard GOST 5632-72 (State Standard).

The same stainless steel according to the AISI and GOST aren't exactly the same - their chemical compositions differ slightly.