Method for the identification of steel pipe
1 fake steel pipe prone to collapse.
Folding is a kind of broken line formed on the surface of steel pipe, which often runs through the whole product. Folding is due to shoddy manufacturers to pursue high efficiency, pressure amount slants big, produce Erzi, a rolling produced folding, folding products after bending will crack and the strength of steel big decline.
2 and the pipe surface often pitted phenomenon.
Ma is due to a defect of groove wear caused by irregular rugged steel surface. As a result of fake and shoddy steel pipe manufacturers to pursue profit, the most frequent rolling mill.
3 fake steel pipe surface easy generation scarring.
There are two reasons: (1) fake and shoddy steel pipe material is not uniform, more impurities. (2). Shoddy material manufacturers guide simple equipment, easy to stick steel, these impurities bite roll easily after produce scar.
4 fake wood surface easy to crack, the reason is that it is entirely adobe, adobe air, cooling in the adobe
In the process, due to the role of thermal stress, crack, after rolling there is a crack.
5 fake and inferior steel tube is easy to scratch, the reason is that the equipment is simple, easy to produce burr, scratch the surface of steel. Deep scratch to reduce the strength of steel.
6 fake steel pipe without metallic luster, reddish or similar iron color, there are two point two reasons, it is entirely adobe. 2, shoddy material rolling temperature is not standard, their steel temperature is through the visual, so can not according to the provisions of the austenite region rolling, the performance of steel natural cannot reach.
7 fake and shoddy steel tube thin and low, often appear to be full of dissatisfaction with the phenomenon, the reason is that manufacturers to achieve large negative tolerance, a few road before the finished product under the weight of large, iron type is small, the hole filling dissatisfaction.
8.False and inferior steel cross section oval. The reason is that manufacturers in order to save materials, finished and before the second pressure amount slants big, this kind of deformed steel bar intensity is greatly decreased and does not conform to the standard screw thread steel dimensions.
Source: Zhejiang Yaang Pipe Industry Co., Limited (www.yaang.com)