A steel tube made of a piece of metal, without a joint on the surface, is called a seamless steel tube. Seamless steel pipe is widely used. The general purpose seamless steel pipe is produced by ordinary carbon structural steel, low alloy structural steel or alloy structural steel. The output is the largest, and is mainly used for conveying fluid pipes or structural parts.
Seamless steel pipe has a hollow section, a large number of pipes used for conveying fluid, such as pipelines, such as oil, natural gas, gas, water and some solid materials. Widely used in the manufacture of structural parts and mechanical parts, such as the oil pipe, automobile transmission shaft, the bicycle frame and steel construction with scaffold with steel pipe manufacturing circular parts, can improve the utilization rate of materials, simplify the manufacturing process, material saving and working hours, has been widely used to manufacture steel tube.
The production process of seamless steel tube in general can be divided into two kinds of hot rolling and cold drawing, cold-rolled seamless steel pipe production process than hot-rolled billet to complex, first to three roller rolling and extrusion to sizing test, if the tube through the cutting machine cutting surface without crack growth response after cutting blank about one meter. Then enter the annealing process. The acid solution should be used for acid washing. When it is pickled, we should pay attention to whether there is a lot of bubbling on the surface. If there is a lot of blister, the quality of the steel pipe can not reach the corresponding standard.
The appearance of cold-rolled seamless steel tube is shorter than that of hot-rolled seamless steel tube, and the wall thickness of cold-rolled seamless steel tube is generally smaller than that of hot-rolled seamless steel tube, but the surface looks more bright than the thick wall seamless steel tube, the surface is not too rough, and there is not much burr on the caliber. The delivery state of hot rolled seamless steel tubes is generally due to hot rolling after heat treatment. Hot rolled seamless steel tube after quality inspection after staff strict hand picked in quality inspection should be carried out after the oil surface, followed by cold drawing experiments, hot rolling process should be carried out after the perforation experiment, if perforated expanding too large to carry out straightening correction. After the straightening, the transmission device is transferred to the flaw detector for the detection experiment. Finally, the label is attached and the specifications are arranged and placed into the warehouse.
Seamless Steel Tube
Outdiameter:10---812.2mm(2/5"—32")
Wall thickness: 1.0---200mm(1/25"—8")
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STANDARD
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GRADE
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ASTM A53/A106
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Gr.A/B
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ASTM A519
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4140, 8720, 4130
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ASTM A213
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T5/T9/T11/T22
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ASTM A335
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T5/T9/T11/T22
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DIN1629
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ST35/ST45/ST52
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DIN2448
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ST37.2/ST37.4/ST52
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EN
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S235, S355
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DIN17175
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ST35.8/ST45.8
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GB
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42CrMo, 40CrNiMo
30CrMnSi, 20CrMnTi
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