The Method of Identifying Fake and Shoddy Thick Wall Seamless Pipe
1. Fake thick-walled Seamless Pipe is prone to folding. Folding is a thick line of Seamless Pipe surface formed a variety of polylines, this defect often runs through the entire product longitudinal. The reason for the folding is due to the pursuit of high efficiency of the manufacturers, the amount of pressure is too large, resulting in the ear, the next rolling to produce folding, folding products will crack after bending, thick-walled Seamless Pipe strength The
2. The appearance of counterfeit thick-walled Seamless Pipe is often pimple. Ma face is due to the serious wear and tear caused by thick groove Seamless Pipe surface irregular rugged defects. As the shoddy thick-walled Seamless Pipe manufacturers to pursue profits, often rolling rolling the most standard.
3. Fake thick wall Seamless Pipe surface prone to scarring. There are two reasons: 1. Fake thick-walled Seamless Pipe material is not uniform, more impurities. 2. Pseudo-poor material manufacturers guide the equipment is simple, easy to stick steel, these impurities are easy to produce a scar after bite.
4. Fake surface is easy to produce cracks, because it is the blank is the adobe, adobe pores and more adobe in the cooling process due to the role of thermal stress, resulting in cracks, after rolling there are cracks.
5. Shameless thick-walled Seamless Pipe is easy to scratch, because the pseudo-defective equipment manufacturers simple, easy to produce burr, scratch thick-walled Seamless Pipe surface. Deep scratching reduces the strength of thick - walled seamless steel tubes.
6. Shameless thick-walled Seamless Pipe without metallic luster, pale or similar to the color of pig iron, there are two reasons, its blank is adobe. 2, pseudo-poor material rolling temperature is not standard, their steel temperature is through the visual, so can not according to the provisions of the austenitic area rolling, thick-walled Seamless Pipe performance naturally can not meet the standard.
7. Shallow thick and thick steel Seamless Pipe is thin and low, often appear full of dissatisfaction with the phenomenon, because the manufacturers to achieve a large negative tolerance, the number of products before the reduction of the amount of large, iron type small, dissatisfied.
8. Shallow thick-walled Seamless Pipe cross-section was oval, because the manufacturers in order to save the material, finished roll two before the pressure is too large, the strength of this rebar greatly reduced, and does not meet the rebar Dimensions of the standard.
9. High-quality thick-walled Seamless Pipe composition evenly, cold shear high tonnage, cutting the end of the surface smooth and tidy, and pseudo-poor material due to poor quality, cut 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.
10. Shameless thick-walled Seamless Pipe material containing impurities, steel density is too small, and the size of the ultra-serious, so in the absence of vernier caliper, it can be weighed check. 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 shoddy thick-walled Seamless Pipe, because it is more than 5% of the negative tolerance. In general, the overall effect of weighing will be better, mainly taking into account the cumulative error and probability theory of this problem.