DMH United Steel Industry CO.,LTD will show you the seamless pipe manufacturing process:
① hot-rolled seamless tube main production process (△ main inspection process):
Tube preparation and inspection △ → Tube heating → Perforation → Tube rolling → Steel tube reheating → Setting (minus) diameter → Heat treatment △ → Finishing tube straightening → Finishing → Inspection △ (Non-destructive, physical and chemical, bench inspection) → Storage
② cold-rolled (pull) seamless steel pipe main production processes:
Blank preparation → pickling lubrication → cold rolling (pulling) → heat treatment → straightening → finishing → inspection
General seamless steel pipe production process can be divided into two kinds of drawing and hot-rolled, cold-rolled seamless steel pipe production process is generally more complex than hot-rolled, the first tube to be three-roll, to be carried out after extrusion Sizing test, if the surface did not respond to cracks after the pipe to cut through the cutting machine, cut into pieces of about one meter in length. And then into the annealing process, the acid pickling to be used acid pickling, pickling surface to pay attention to whether there is a lot of foam, if there is a lot of blister produced steel quality does not meet the appropriate standards. The appearance of cold-rolled seamless steel pipe is shorter than hot-rolled seamless steel pipe, cold-rolled seamless steel pipe generally smaller thickness than hot-rolled seamless steel pipe, but the surface looks thicker than thick-walled seamless steel pipe, the surface is not too More rough, caliber nor too much bur r.
Hot-rolled seamless steel pipe delivery status is generally hot-rolled state after the heat treatment delivery. Hot-rolled seamless steel pipe after quality control to go through the staff of the strict manual selection, after the quality inspection to be oiled, and then followed by a number of cold-drawn experiments, hot-rolled after the experiment to be perforated If the hole diameter is too large to be straightening correction. After straightening, it will be sent to flaw detection machine by transmission device for testing. Finally, it will be labeled and placed in the warehouse after the specifications are arranged.
Round Tube → Heating → Piercing → Three-roll Slant Rolling, Rolling or Extrusion → Tube Removal → Sizing (or Reducing) → Cooling → Straightening → Hydrostatic Testing (or Flaw Detection) → Marking → Storage Seamless Steel Tube Is made of steel ingot or solid tube perforation made of capillary, and then by hot-rolled, cold-rolled or cold dial made. Seamless steel pipe specifications with the outer diameter * mm mm said.
The outer diameter of hot-rolled seamless pipe is generally greater than 32mm, wall thickness 2.5-200mm, cold-rolled seamless steel pipe diameter can be 6mm, wall thickness can be 0.25mm, thin-walled tube diameter 5mm wall thickness less than 0.25mm, cold Hot rolling rolling than the high dimensional accuracy.
The general use of seamless steel pipe is 10,20,30,35,45 and other high-quality carbon steel 16Mn, 5MnV low-alloy structural steel or 40Cr, 30CrMnSi, 45Mn2, 40MnB bonded steel such as hot-rolled or cold rolled. 10,20 and other low-carbon steel seamless pipe is mainly used for fluid pipelines. 45,40 Cr and other medium-carbon steel seamless pipe used to create mechanical parts, such as cars, tractors force parts. Generally use seamless steel pipe to ensure strength and flattening test. Hot-rolled steel pipe to the state of hot-rolled or heat treatment delivery; cold-rolled state to deliver heat treatment.
Hot rolling, as the name implies, has a high temperature of the rolling stock, so that the deformation resistance is small and a large amount of deformation can be achieved. Take the rolling of steel plate as an example, the thickness of the continuous casting slab is generally about 230mm, and after rough rolling and finish rolling, the final thickness is 1 ~ 20mm. At the same time, due to the aspect ratio of steel is small, relatively low dimensional accuracy requirements, is not prone to plate-shaped problems, mainly to control the convexity. For the organization requirements, the general control by rolling to achieve control, that is, the control of rolling finishing rolling temperature, finishing temperature. Round tube → heating → perforation → → → annealing → pickling → oiled (copper plating) → Multi-pass cold drawing (cold rolling) → → → billet heat treatment straightening → hydrostatic test (testing) → mark → storage.