Hebei Yehui Metal Materials Co., Ltd.

Detailed explanation of the production process of galvanized pipe

1. Raw material preparation
The base material of the galvanized pipe is a black pipe (ordinary steel pipe). Steel that meets national standards (such as GB/T 3091) must be selected to ensure that its chemical composition and mechanical properties meet the standards.

2. Pretreatment (cleaning and pickling)
Alkaline washing: remove oil and organic matter on the surface of the steel pipe3.
Pickling: Use hydrochloric acid to remove iron oxide to make the surface of the steel pipe clean.
Rinse: Clean the residual acid to prevent affecting the quality of subsequent galvanizing.

3. Hot-dip galvanizing
The steel pipe is immersed in molten zinc liquid (about 450℃) to combine the zinc layer with the steel pipe matrix to form a uniform and dense anti-corrosion layer. The hot-dip galvanizing process is more durable than cold galvanizing and is the current mainstream method.

4. Post-treatment
Cooling: Water cooling or natural cooling to solidify the zinc layer.
Internal and external blowing: Use high-pressure air or steam to remove excess zinc liquid in the pipe to ensure a smooth inner wall.
Passivation treatment: Enhance the corrosion resistance of the zinc layer and extend its service life.

5. Quality inspection and packaging
Coating inspection: Copper sulfate test verifies the uniformity of the zinc layer.
Mechanical properties test: Ensure that the strength and bending performance of the steel pipe meet the standards.
Packaging: Warehouse after rust-proof treatment to prevent transportation damage