DUPLEX STEEL PIPE/TUBE

The microstructure of duplex seamless pipe is approximately 50% ferrite (body-
centered cubic structure) and 50% austenite (face-centered cubic structure)
crystal structure. The two phases coexist as a stable mixture, but this is
different from two-phase alloys, where one of the two phases appears as a
precipitate. The alloying elements in duplex stainless steel tubes are ferritic
(eg chromium, silicon, molybdenum) or austenitic (eg carbon, nickel, nitrogen),
which means that they favor the formation of the ferritic and austenitic
phases, respectively. As a professional duplex stainless steel pipe
manufacturer in China, Yuhong Group provides quality super duplex tubing
solutions.

DIFFERENT TYPES OF DUPLEX STEEL PIPE
Duplex stainless pipe are part of the stainless steel family. Duplex(
austenitic-ferritic) means their metallurgical structure consists of two
phases. Compare with the normal 304 316 stainless steel, they can provide
better corrosion resistance, particularly chloride stress corrosion and
chloride pitting corrosion, and higher strength. And it has higher Chromium
20%-28%, and lower nickel, up to 9% and 0.05-0.50% than austenitic stainless
steel, which gives good cost benefits.

DUPLEX STAINLESS STEEL PIPE GRADES

The most widely used is ASTM ASTM (American Society for Testing and Materials
International), and ASME(American Society of Mechanical Engineers). And the
general standard for the duplex stainless steel seamless or welded tube or pipe
can be ASTM A789/ASME SA789, ASTM A790/ASME SA790, ASTM A928/ASME SA928. They
give very detailed requirements on the material, test, and others.

DUPLEX SS SEAMLESS PIPE APPLICATIONS
Pipe duplex is known for its excellent combination of good mechanical
properties and high corrosion resistance. The wide range of advantages means
that it can be used in many different applications: for example, chemical
processing, transport, and storage in the industrial sector, such as seawater
heat exchange for high chloride environments and production of chemical
containers. The SS duplex pipe can also be applied to pipelines for oil and gas
production and transportation, such as oil and gas exploration and offshore
drilling platforms.

Nickel alloys are the most outstanding and useful materials in the manufacture
of pipes and tubes for industrial applications. Their inherent properties make
them versatile. Nickel alloys are particularly resistant to corrosion and can
be used in high-temperature environments. Because nickel alloys are highly
ductile, they can be processed very efficiently into pipes and tubes while
maintaining the corresponding strength. This makes them ideal for heat
exchangers in chemical processing. Nickel-based tubing is also used in steam
generators, aircraft systems, and oil and gas extraction.

DUPLEX STEEL PROPERTIES
At elevated temperatures, mechanical properties such as strength and toughness,
as well as corrosion resistance, of dual-phase steels are reduced. This
phenomenon is called embrittlement. The worst temperature at which
embrittlement occurs is 475 °C; however, the formation of α' phases can begin
to occur at temperatures as low as 300 °C, which limits the maximum service
temperature for dual-phase steels.

Typical duplex pipe material has higher yield strengths than typical
martensitic, austenitic, and ferritic stainless steels. However, since
intermetallics begin to precipitate above 300 °C and become brittle near
cryogenic temperatures, their operating temperature range is narrow.

There are many ss pipe suppliers, but we are one of the best choices for you.

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