鋼管具有性能好、強度高等優點,在工業生產中是非常常見的應用,為了充分發揮鋼管的良好性能，有時必須對鋼管進行鍍鋅維護，這樣才能提高他的使用年限。 鍍鋅管具有耐腐蝕和使用壽命長的雙重優點，且價格相對較低，因此目前其應用率越來越高， 特別是作為一種常用的運輸排水管。
Steel pipe has the advantages of high strength and good performance, which has been widely used in industrial production. In order to give full play to the good performance of steel pipe, sometimes the steel pipe must be galvanized for maintenance, so as to improve its service life Galvanized pipe has the double advantages of corrosion resistance and long service life, and the price is relatively low, so its application rate is more and more high, especially as a commonly used transportation drainage pipe.
At this time, someone will ask if the galvanized pipe used for water transportation will rust?
Because the corrosion of steel pipe must meet two conditions, one is moisture, the other is extremely important air （i.e. oxygen）。
Then as a water supply pipe, the steel pipe is always full of water under daily conditions, and it is not easy to rust under full water conditions.
That is to say, because the pipe is full of water, the dissolved oxygen in the water is limited, and the pipe wall also has galvanized anti-corrosion coating, these two reasons can greatly reduce the probability of galvanized pipe suffering from corrosion.
However, this does not mean that corrosion can be completely controlled,排水管就是個特例，排水管不會每日都是充滿的狀態，而且排水系統還將排放局部腐蝕性污水，鍍鋅管很快就會被腐蝕。
The drain pipe is a special case, the drain pipe will not be full every day, and the drainage system will also discharge local corrosive sewage, and the galvanized pipe will be corroded soon.
Some precautions for galvanizing process:
1. The premise of galvanized pipe galvanizing is to polish off the galvanized layer at the welding position, otherwise bubbles, sand holes, false welding, etc. will occur. It also makes the weld brittle and hard.
2. Zinc and iron can form intermetallic brittle compounds. These brittle phases reduce the plasticity of the weld metal and lead to cracks under tensile stress. If the weld fillet, especially the T-joint fillet, is most likely to have penetration cracks.
3. In the welding process of galvanized steel, the zinc layer on the surface and edge of the groove will generate oxidation, condensation and evaporation under the action of arc heat, which will make white smoke and steam volatilize and easily cause weld porosity.
4. Due to the evaporation of zinc, a lot of white smoke volatilizes, which is harmful to people. Therefore, it is necessary to polish and treat the galvanized layer at the welding position.
5 groove sizes near the left side and centralized groove of galvanized layer shall be handled carefully, without blunt edge, centralized control shall be stopped, and two-layer welding process shall be carried out to reduce the possibility of incomplete penetration.
6. Welding method: when welding the first layer of multi-layer welding, try to condense and evaporate the zinc layer to make it escape from the weld, which can greatly reduce the residual liquid zinc in the weld.