Characteristics and types of stainless steel

By definition, stainless steels are capable of containing more than 12% of Cr (chromium). With these characteristics, stainless steels are more resistant than other steels to oxidation and chemical corrosion. When we talk about stainless steel, we are therefore referring to alloys based on iron, chromium, carbon, and also other elements such as nickel, molybdenum, silicon, titanium.

 

Among the sectors of greatest use of stainless steel, we remember the chemical industries, construction and furniture, food and pharmaceutical companies.

 

The types of stainless steels

The search for companies that deal with the trade and sale of stainless steel can be done online, where you will find many alloy steel seamless pipe suppliers in India, ready to offer you the best services. If you are looking for precision, you can rely on the P5 Pipe suppliers who produce and sell precision drawn tubes, with special welds such as the TIG technique. Cutting-edge companies also have a tube cutting department, equipped with modern equipment able to satisfy every request.

 

Among the products offered, precision tubes are the most requested. If you are looking for the absolute best quality, you will surely find P91 Pipe suppliers able to provide you with the required material. Relying on professionals in the sector means relying on true experts in the processing of stainless steel pipes, carefully followed in all its phases, from design to product resistance tests to marketing.

 

AISI 304 - AISI 316 stainless steel is divided into:

  •            Electronic
  •            brushed surface finish (standard)
  •            Satin surface finish
  •            Glossy surface finish
  •            Seamless
  •            Perforated bars (mechanical tube)

All products must be supplied with specific certification, which reports all the technical characteristics. We remind you that among the most common standard finishes for rolling, there is the finish for hot-rolled sheets and the passing finish. This process involves cold rolling with a thickness reduction of about 20% compared to the hot one. The surface layer is of considerable importance, especially for the purposes of resistance to atmospheric agents and, therefore, to corrosion.

 

Duplex steel

It is hybrid chromium steel: the chromium content ranges from 18 to 26% and that of nickel from 4.5 to 6.5%. This product has insufficient quantities to determine a totally austenitic microcrystalline structure (which therefore remains partly ferritic). Almost all of its variants contain between 2.5 and 3% molybdenum.

 

There are also forms of Duplex, which do not contain Molybdenum and have nickel contents lower than 4.5%.

The fundamental properties are:

  •            Peculiar microcrystalline structure known as a duplex, austenitic and ferritic, which gives more resistance to stress corrosion cracking;
  •            Greater degree of passivation due to the higher chromium content (and the presence of Molybdenum) and therefore better resistance to pitting than steel 18-8;
  •            Good weldability and formability;
  •            High tensile strength and yield strength.

The most common uses of IS 1239 Pipe are in heat exchangers, materials handling machines, and tanks for liquids with a high concentration of chlorine.