The microstructure of duplex stainless steel 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.
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.
Pipe duplex is known for its excellent combination of good mechanical properties and high corrosion resistance. The wide range of advantages means that duplex SS pipe 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.
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.
|Specification||Material of Duplex Available|
|ASTM A790/ASME SA790||UNS S31803, S32205,S32750,S32760,S32304,S32900|
|For Seamless and Welded Pipe|
|ASTM A789/ASME SA789||UNS S31803, S32205,S32750,S32760,S32304,S32900|
|For Seamless and Welded Tube, U-Bending Available|
|ASTM A928/ASME SA928||UNS S31803, S32205,S32750,S32760,S32304|
|For Electric Fusion Welded with Addition of Fill Metal|
Yuhong Group focus on duplex stainless steel pipe for more than 15 years. Our duplex stainless steel tubes have been exported to more than 55 countries in the world. Over 90% of our clients will place repeat orders because of our good quality and service. For YUHONG, quality is the very first importance. As a reliable duplex stainless steel pipe manufacturer, we always aim to provide the best quality product to our clients. If you are looking for good quality duplex stainless steel seamless or welded pipe. YUHONG will be your best choice. YUHONG provide varied duplex stainless steel pipe choices with different grades and specifications. From 6.35mm-219m in seamless type, and 6.35mm-3600mm in welded type. Believe you can always find the suitable one for your project. Customization is also available. YUHONG is always your good partner in China.
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