ASTM A789 /A790 Duplex Steel Pipes 2205 S31803 S22053 6 Meter DIN1.4462 Seamless Tubing

Duplex stainless steels are a family of stainless steels. These are called duplex (or austenitic-ferritic) grades because their metallurgical structure consists of two phases, austenite (face-centered cubic lattice) and ferrite (body centered cubic lattice) in roughly equal proportions. They are designed to provide better corrosion resistance, particularly chloride stress corrosion and chloride pitting corrosion, and higher strength than standard austenitic stainless steels such as type A2/304 or A4/316. The main differences in composition, when compared with an austenitic stainless steel is that the duplex steels have a higher chromium content, 20-28%; higher molybdenum, up to 5%; lower nickel, up to 9% and 0.05-0.50% nitrogen. Both the low nickel content and the high strength (enabling thinner sections to be used) give significant cost benefits. They are therefore used extensively in the offshore oil and gas industry for pipework systems, manifolds, risers, etc. and in the petrochemical industry in the form of pipelines and pressure vessels. In addition to the improved corrosion resistance compared with the 300 series duplex stainless steels also have higher strength. For example, a Type 304 stainless steel has a 0.2% proof strength in the region of 280 MPa (41 ksi), a 22%Cr duplex stainless steel a minimum 0.2% proof strength of some 450 MPa (65 ksi) and a superduplex grade a minimum of 550 MPa (80 ksi).

1. Are you a manufacturer or a trading company?
   We are a manufacturer for most sizes listed and can assist with the entire project package if in need.
2. Where are your plants located in China?
   By 2012, we have a stainless  steel pipe in Wuxi  City and a stainless steel plant in Lishui City, with details available on our website.
3. Do you have a certified quality assurance system?
   Yes, we boasts ISO 9001:2015 certified factories.
4. Can I visit your plant before placing an order?
   Of course, we welcome and respect all clients' plant visits.
5. What is the market percentage for domestic and international sales?
   Our domestic market share is approximately 70%, with international sales accounting for less than 30% over the past 5 years.