How to identify the quality of steel pipe is good or bad?

In the rapid development of steel at the same time, the market some of the fake steel pipe products have also appeared, then how to correctly and accurately identify the quality of steel is good or bad?

1, the appearance of counterfeit steel pipe often pimple phenomenon.

Ma face is due to the serious wear and tear caused by irregular steel surface uneven rugged defects. As the fake steel pipe manufacturers to pursue profits, often rolling rolling the most standard.

2, the cross-section of the counterfeit steel pipe is oval, because the manufacturers in order to save the material, the first roll of the product before the pressure is too large, the strength of this rebar greatly reduced, and does not meet the size of rebar The

3, the composition of high-quality steel uniform, cold shear high tonnage, cutting the end of smooth and tidy, and pseudo-poor material due to poor quality, cutting the end of the face often have the phenomenon of meat, that is uneven, and no metallic luster. And because the false product manufacturers cut off the small head, head and tail will appear big ears.

4, the size of fake steel pipe diameter fluctuations, because:1, steel temperature instability of the yin and yang face. 2, the composition of steel is not uniform. 3, due to poor equipment, low ground strength, rolling bounce large. There will be a greater change in the same week, so that the uneven force of steel tend to produce fracture.

5, fake steel pipe material containing impurities, steel density is too small, and the size of the ultra-serious, so in the absence of vernier caliper case, you can weigh it. For example, for rebar 20, the national standard specifies a maximum negative tolerance of 5%, the length of 9M when its single theoretical weight of 120 kg, its minimum weight should be: 120 X (l-5%) = 114 kg , Weighing out the actual weight of a single 114 kg smaller, it is counterfeit steel, because it is a negative tolerance of more than 5%. In general, the overall effect of weighing will be better, mainly taking into account the cumulative error and probability theory of this problem.

6, fake steel pipe easy to scratch, because the fake steel pipe manufacturers equipment simple, easy to produce burr, scratch the steel surface. Deep scratch to reduce the strength of steel.

7, fake steel pipe surface prone to scarring.

There are two reasons: (1) fake steel pipe material is not uniform, more impurities. (2) pseudo-poor material manufacturers guide equipment simple, easy to sticky steel, these impurities are easy to produce scar after the bite roll.

8, high-quality pipe trademarks and printing are more standardized.

9, fake steel rebar longitudinal steel often wavy.