鍍鋅方管的鍍鋅分層以及彎曲強(qiáng)度：熱鍍鋅方管合金層與純鋅層、鋼管基體融為一體。故其耐腐蝕能力強(qiáng)。鋅層是電鍍層，鋅層與鋼管基體獨立分層。鋅層較薄，鋅層簡單附著在鋼管基體上， 鍍鋅方管容易脫落。故其耐腐蝕性能差。鍍鋅方管在新建住宅中，禁止使用冷鍍鋅鋼管作為給水管。

Galvanized layering and bending strength of galvanized square pipe: Hot-dipped galvanized square pipe alloy layer is integrated with pure zinc layer and steel pipe matrix. Therefore, it has strong corrosion resistance. Zinc layer is an electroplating layer, and zinc layer is separately stratified with the steel tube matrix. The zinc layer is thin, and the zinc layer is simply attached to the steel tube matrix. The galvanized square tube is easy to fall off. Therefore, its corrosion resistance is poor. Galvanized square pipes are prohibited to be used as water supply pipes in newly built residential buildings. 熱鍍鋅方管彎曲試驗公稱口徑不大于50mm的鍍鋅鋼管應(yīng)作冷彎曲試驗。彎曲角度為90°，彎曲半徑為外徑的8倍。

The bending test of galvanized square pipe with nominal diameter less than 50 mm should be carried out by cold bending test. The bending angle is 90 degrees and the bending radius is 8 times of the outer diameter.