How to dinstinguish camouflage thick wall steel tube
1. camouflage thick wall steel tube folding is seen. Fold is formed on the surface of the thick wall steel pipe line, this kind of defect often throughout the entire product longitudinal. Causes of fo...
1. camouflage thick wall steel tube folding is seen. Fold is formed on the surface of the thick wall steel pipe line, this kind of defect often throughout the entire product longitudinal. Causes of fold is due to the pursuit of the false and inferior, high efficiency, large reduction, handle, when the next rolling produce folding, folding products will be cracking after bending, strength of steel.
(2) camouflage thick wall steel pipe appearance often have pitted surface phenomenon. Pits was caused by worn groove steel irregular uneven defects. Due to the false and inferior thick wall steel pipe manufacturer to pursuit of profit, often appear groove rolling the overweight.
(3) camouflage thick-walled steel pipe surface are prone to scarring. There are two reasons: (1). And inferior steel pipe material uneven, impurities. (2). And inferior material manufacturer guide equipment simple, easy to stick steel, these impurities after the roll bite are prone to scarring.
4. Easy generation and inferior material surface crack, the reason is that it's blank is adobe, adobe air, adobe in the process of cooling due to the effect of thermal stress, cracks, after rolling there is crack.
5. Easy to scratch and inferior thick-walled steel pipe, the reason is false and inferior thick-walled steel pipe factory equipment simple, easy to produce burr, scratch steel surfaces. Deep scratches to reduce the strength of the steel.
6. camouflage thick-walled steel pipe without metallic luster, reddish or similar to the color of the pig iron, two point two, its billet is adobe reasons. 2, and inferior material rolling temperature is not standard, their steel temperature is through visual inspection, so can't austenitic area of the rolling by the regulation, the performance of the steel natural can't up to standard.
7. camouflage transverse reinforcement and low, the thick wall steel pipe often appeared phenomenon of discontent, because manufacturers to achieve big minus tolerance, finished product quantity of the previous way slants big, small iron type, groove filling.
8 camouflage thick-walled steel pipe cross-section oval, because the factory in order to save material, the quantity of the finished product roll before 2 slants big, the strength of rebar is greatly decreased, but also do not conform to the standard of rebar shape size.
9. The high quality steel composition is uniform, cold shearing machine high tonnage, cutting head end face smooth and neat, and shoddy material because the material is poor, cutting head end face often have meat, or uneven, and no metallic luster. And due to low and inferior material manufacturers cut head, end there will be a big handle.
More than 10. And inferior thick-walled steel pipe material with impurity, steel small density, size and out-of-tolerance is serious, so in the absence of vernier caliper, can be checked to weigh it. For rebar 20, for example, maximum minus tolerance specified in the national standard of 5%, scale of 9 m in the theory of single weight is 120 kg, it should be the smallest weight: 120 X (l - 5%) = 114 kg, 114 kg weigh out the weight of the single than small, is false and inferior steel, the reason is that it is negative tolerance more than 5%. In general the whole amount to match the effect will be better, mainly considering the cumulative error and probability theory to this problem.
11. camouflage thick-walled steel pipe diameter is volatile, the reason is; L, the steel temperature instability has Yin and Yang. 2, the composition of steel is not uniform. 3, due to poorly equipped, foundation strength is low, mill's bounce. There will be a larger inner diameter changes of the same week, the steel bar caused by uneven on fracture.
12. The high quality tube logo and printing are specification.
13. More than three steel pipe diameter 16 big thread, the spacing between the two trademark all over IM.
14. camouflage steel rebar longitudinal reinforcement often undulate.
Hunan great steel pipe have pipe inventory of good quatlity wall thickness steel pipe.
Source: Free Articles from ArticlesFactory.com
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