Product details table:

Physical and chemical properties:

Physical properties

Appearance:

Galvanized steel pipes usually present a metallic silver-gray color with a smooth and bright surface due to the zinc coating. The zinc layer provides excellent corrosion resistance and can be further enhanced through different surface treatment processes, such as hot-dip galvanizing or electro-galvanizing.

Density:

The density of galvanized steel pipes is generally around 7.85g/cm³, which is similar to that of carbon steel. However, the additional zinc coating slightly increases the overall weight compared to non-galvanized steel pipes.

Melting point:

The melting point of the base steel material is relatively high, typically around 1425-1540℃. However, the zinc coating has a much lower melting point (about 420℃), so care must be taken in high-temperature environments to avoid damaging the zinc layer.

Coefficient of thermal expansion:

The coefficient of thermal expansion for steel is relatively low, typically around 11.7×10⁻⁶/℃. This feature ensures that galvanized steel pipes maintain good dimensional stability under temperature fluctuations, making them suitable for various environmental conditions.

Thermal conductivity:

The thermal conductivity of steel is moderate, with a coefficient of about 45-55W/(m・K). While the zinc coating slightly reduces the thermal conductivity, it still performs well in applications where heat transfer is required.

Electrical conductivity:

Galvanized steel pipes have relatively low electrical conductivity compared to pure metals like copper. The electrical conductivity of steel is about 10⁶ S/m, but the zinc coating may further reduce its efficiency in electrical applications.

Chemical properties

Corrosion resistance:

One of the most important features of galvanized steel pipes is their excellent corrosion resistance. The zinc coating acts as a sacrificial anode, protecting the underlying steel from rust and oxidation. For example, in outdoor or humid environments, galvanized steel pipes exhibit superior durability compared to non-galvanized steel pipes. The thicker the zinc layer, the longer the pipe can resist corrosion.

Antioxidation:

The zinc coating on galvanized steel pipes provides good oxidation resistance at room temperature and in mildly elevated temperature environments. However, in extremely high-temperature conditions, the zinc layer may oxidize, reducing its protective properties.

Chemical stability:

In general chemical environments, galvanized steel pipes exhibit high chemical stability and are resistant to mild acids, alkalis, and water exposure. However, in highly corrosive environments, such as those containing strong acids (e.g., sulfuric acid) or alkalis, the zinc layer may degrade over time, affecting the pipe’s longevity.

Passivation:

Although galvanized steel pipes do not undergo traditional passivation like stainless steel, the zinc coating itself forms a protective oxide layer when exposed to air. This layer enhances the pipe’s resistance to corrosion and oxidation. In some cases, additional treatments, such as chromate conversion coatings, can be applied to further improve the zinc layer’s durability.

Application:

Galvanized steel pipes are widely used in various industries due to their excellent corrosion resistance, strength, and affordability. In the construction industry, they are commonly used for water supply, drainage systems, and scaffolding due to their durability and ease of installation. In agriculture, they are used for irrigation systems and greenhouse structures. In the energy sector, galvanized steel pipes are employed in oil and gas pipelines, as well as in electrical conduit systems. Additionally, they are used in automotive manufacturing, furniture production, and infrastructure projects where long-term performance in harsh environments is required.