Double phase steel flange, as the name suggests is a double phase steel bar, ingot or plate and the like as raw materials produced by the flange, for short, double phase steel flange, flange is also called flange or flange. The parts that are connected to each other by pipes. Connect to tube end. Flanges have holes, can be threaded bolts, so that the two flanges close. Gasket between flanges. The flange connection consists of a pair of flanges, a gasket and a number of bolts and nuts. The gasket is placed between the sealing surface of two flanges. After the nut is tightened, the specific pressure on the surface of the gasket reaches a certain value and generates deformation, and fills the uneven place on the sealing surface, so that the connection is tight without leakage. Some pipe fittings and equipment have flanged, also belong to flange connection. Flange connection is an important connection mode in pipeline construction.

Duplex steel flanges use duplex steel as raw materials for production, the so-called duplex stainless steel is in the solution of its ferrite phase and austenite about half, the general amount of less phase content also need to reach 30%. When the content of C is low, the content of Cr and Ni ranges from 18% to 28% and 3% to 10% respectively. Some steels also contain alloying elements such as Mo, Cu, Nb, Ti and N. This kind of steel has the characteristics of austenite and ferritic stainless steel. Compared with ferritic steel, it has higher plasticity and toughness, no room temperature brittleness, and significantly improved intergranular corrosion resistance and welding performance. Meanwhile, it also has the characteristics of 475℃ brittleness, high thermal conductivity and superplasticity. Compared with austenitic stainless steel, its strength is higher and its resistance to intercrystalline corrosion and chloride stress corrosion is improved obviously. Duplex stainless steel has excellent corrosion resistance and is also a nickel - saving stainless steel.