The friction property of metal composite pipes with plastic-plating was measured and compared with that of zinc-plating and polypropylene pipes of the same size.
测定了金塑复合管的阻力性能，并与同一规格的镀锌管、聚丙烯管进行比较。
2
Zincplating chromic acid salt after the passivation, corrosion resistance can improve 6 to 8 times.
锌镀层经铬酸盐钝化之后，耐蚀性可提高6 ~ 8倍。
3
This step is the main, first to control the temperature, time and liquid zincplating steel plate is removed from the liquid zinc in speed.