What are the Galvanizing Methods for Thick-walled Seamless Steel Pipes?

Thick-walled seamless steel pipe is a kind of seamless steel pipe. It is named mainly because of the thickness of the wall. It is widely used in pipeline installation to transport chemical liquids such as petroleum and water. Generally, the wall thickness is more than 20 mm. The following is the manufacturing process of the steel pipe: the raw material of the steel pipe is a steel pipe blank, which must be cut by a cutting machine into a blank of about 1 meter in length and sent to the furnace via a conveyor belt Internal heating. The billet is fed into the furnace and heated at a temperature of approximately 1200°C. The fuel is hydrogen or acetylene. During this period, galvanizing will be carried out. What are the common galvanizing methods for thick-walled seamless steel pipes?

There are two types of thick-walled seamless steel pipes: hot-dip galvanized and electro-galvanized. Hot-dip galvanizing includes wet method, dry method, lead-zinc method, redox method and so on.

The main difference between different hot-dip galvanizing methods is what method is used to activate the surface of the pipe body to improve the quality of galvanizing after the acid immersion cleaning of the steel pipe. Dry method and redox method are mainly used in production. The surface of the electro-galvanized zinc layer is very smooth and compact, with uniform structure; it has good mechanical properties and corrosion resistance; the zinc consumption is 60% to 75% lower than that of hot-dip galvanizing. Electro-galvanizing is technically complicated, but it must be used for single-sided coating, double-sided coatings with different inner and outer surface coating thicknesses, and thin-walled pipe galvanizing.

In addition, the mechanical and chemical properties of galvanized steel pipes are relatively stable, which is also the reason why they are vigorously promoted in various industries.

Tips: ASTM A53 covers seamless and welded steel pipe with nominal wall thickness. The surface condition is usually black and hot-dipped galvanized. ASTM A53 is produced mainly for pressure and mechanical applications, and is also used for transport of steam, water, gas line pipes. A53 ERW pipe is a typical carbon steel pipe (electric resistance welded).