High Temperature Tube ASTM A312 TP309cb Schedule 40 SS Seamless Pipe

Characteristic

309Cb belongs to the Austenitic series stainless steel, containing niobium element, which can resist high-temperature oxidation, corrosion and deformation caused by thermal cycling. It has good weldability and machinability.

309Cb is widely used in petrochemical, electric power, pharmaceutical and other industries under high temperature conditions. It is often used in the manufacture of high temperature stoves, petroleum equipment and chemical equipment.

Chemical Composition

Mechanical Properties

Physical Properties

To improve the corrosion resistance of steel, the following measures can be taken:

(1) to form a stable passivation film on the surface of the steel. Passivation is due to the action of metal and medium to produce a thin protective film, the existence of the protective film hinders the anode process, thus improving the chemical stability of the metal. After chromium is contained in the steel, chromium is also contained in the passivation film. The higher the chromium content in the steel, the higher the chromium content in the TP309cb stainless steel tube film, which will increase the stability of the film, and its thickness is above 1nm. Therefore, the corrosion resistance of stainless steel is mainly caused by a chromium-rich oxide film with a thickness of about 1nm or more. The type of medium and other elements in the steel will affect the stability of the passivation film.

(2) The steel obtains a single solid solution structure. For example, 18Cr-8Ni austenitic stainless steel has high corrosion resistance only after solution treatment to obtain a single uniform austenitic structure

(3) Increase the electrode potential of the solid solution. The corrosion resistance of the metal is closely related to the type, concentration, temperature, pressure and other conditions of the medium, and the oxidation capacity of the medium has the greatest impact.

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