Galvanizing of seamless steel pipes

A seamless steel pipe is produced from a solid round steel billet that is first heated and then pushed or pulled over a mold, shaping the steel into a hollow tube. This process results in a pipe without any seams or joints, distinguishing it from welded pipes. The absence of seams gives seamless pipes superior strength and reliability, particularly under demanding conditions such as high pressure, high temperature, and corrosive environments, making them ideal for critical applications in industries like oil and gas, power generation, and chemical processing.

Galvanizing Seamless Steel Pipes

- Characteristics:

Zinc, when exposed to dry air, remains relatively stable, maintaining its appearance without significant discoloration. In water or humid conditions, zinc reacts with oxygen or carbon dioxide to form a protective layer of oxide or alkaline zinc carbonate. This film acts as a barrier, preventing further oxidation of the zinc and thereby protecting the underlying steel from corrosion. However, zinc is vulnerable to corrosion in the presence of acids, alkalis, and sulfides. To counter this, the galvanized layer typically undergoes passivation treatment, which enhances its corrosion resistance. During passivation, the galvanized surface is treated with chromic acid or a chromate solution, forming a passivation film that is less reactive with moisture, significantly boosting its durability in corrosive environments.

For specific applications, such as spring parts, thin-walled components with a wall thickness of less than 0.5mm, and steel parts that demand high mechanical strength, it is crucial to remove hydrogen from the metal after galvanizing to prevent hydrogen embrittlement. However, copper and copper alloy parts do not require this dehydrogenation process. The galvanizing process is not only cost-effective but also straightforward, making it a widely used method for protecting steel.

- Application:

Galvanizing is particularly well-suited for use in environments where atmospheric exposure is a concern, providing long-lasting protection against rust and corrosion. However, it is important to note that galvanizing is not recommended for parts subjected to constant friction, as the zinc coating can wear off under such conditions, diminishing its protective benefits. This makes galvanizing ideal for structural components and other non-frictional applications where long-term durability and resistance to environmental factors are critical.