PRODUCT DESCRIPTION

Zirconium tube rod is an alloy tubular material made of metallic zirconium and other metals. Due to the excellent nuclear properties and corrosion resistance of zirconium, zirconium alloy tube rods are often used in the nuclear fuel components and internal structures of water-cooled reactors and are important nuclear materials. Pure zirconium tube rods are mainly used to manufacture chemical equipment, because they are expensive and are not used in large quantities. The chemical composition and uses of commonly used zirconium tube rods are shown in the table, among which zirconium-tin alloy tube rods are used in larger amounts.

PROCESS CHARACTERISTICS

(1) Zirconium has a strong affinity with gas. It starts to react with oxygen, hydrogen, and nitrogen at about 200, 300, and 400°C respectively. The reaction is rapid at higher temperatures, so casting and heat treatment must be performed in a vacuum furnace. When performing thermal processing in the atmosphere, proper protective measures should be taken and the operating time at high temperatures should be shortened.

(2) The friction coefficient between zirconium and the mold is high and it is easy to adhere to the surface of the mold; the thermal effect of plastic deformation is significant, and good lubrication conditions are required during processing.

(3) Processing specifications have a sensitive impact on product performance. Particular attention should be paid to controlling the cold working and heat treatment processes before finished products to meet usage requirements.

(4) The dimensional accuracy and surface quality of pipes and bars are very demanding. Therefore, process equipment should have good accuracy, and tool and mold design and production should be advanced and reasonable.

HEAT TREATMENT

The final intermediate annealing of zirconium-tin alloy is changed to rapid cooling in the high-temperature zone of β phase or α phase, and then the finished pipe is obtained by final cold working and finished product heat treatment. The corrosion resistance is better. The reason may be that the metallographic structure of the finished pipe The second phase is finely dispersed and increases the solid solution content of alloy elements in the α-Zr matrix.

Zirconium-niobium alloy is a heat treatment-strengthened alloy, and quenching and cold working aging treatment can also improve corrosion resistance.