Novel type composite galvanized pipe and processing method thereof

The invention discloses a novel type composite galvanized pipe and a processing method thereof. The novel type composite galvanized pipe comprises a steel pipe (1), a zinc-iron alloy layer (2) wrappedon the steel pipe (1), a pure zinc layer (3) wrapped outside the zinc-iron alloy layer (2), and a passivation layer (4) wrapped outside the pure zinc layer (3). The novel type composite galvanized pipe is composed of the steel pipe, the zinc-iron alloy layer, the pure zinc layer and the passivation layer, the layers of the pipe are connected tightly, the zinc-iron alloy layer has a fine, uniformand flat structure and has no bending wrinkles, the passivation layer is free of delamination, weather resistance and corrosion resistance are excellent, and the composite galvanized steel pipe for refrigeration is resistant to a neutral salt spray test for 120 h or above. 本发明公开了种新式复合镀锌管：包括钢管（1）、包覆于钢管（1）的锌铁合金层（2）、锌铁合金层（2）外包覆的纯锌层（3）；纯锌层（3）外包覆钝化层（4）。及其加工方法。本新式复合镀锌管由钢管、锌铁合金层、纯锌层和钝化层组成，该管各层之间联结紧密，锌铁合金层组织细致、均匀、平整，弯曲无褶皱、钝化层无脱层，具