Seamless transported to a cold bed to cool after perforation, rolling, reeling, sizing, and other hot-pressure processing step. Pipe type cooling bed to use the workshop are: rack type cooling bed, spiral type cooling bed, step-cooling bed and so on. After cooling, the tube needs to be sawing, cutting head and cut to length. In order to cut straight pipe sections, smooth and burr-free, the machine will often use steel cut length. In order to eliminate processing, cooling and transport pipe during the bending, to ensure the quality and improve the yield, but also on pipe straightening. Pipe straightening usually in different types of oblique roller straightening machine completed. After finishing the above steps after processing of steel pipes must be inspected (include: surface quality, size, shape and appearance inspection orders according to national standards and contract requirements for chemical composition, physical and mechanical properties check, for example, pressure, curling, flattening, mechanical properties and metal tissue, etc.), and finally as a light pipe storage, delivery. There are a small number of surface defects, but can be repaired pipe, and then grinding wheel available prior inspection and approval prior to shipping.
Modern steel plant have a huge machine shop, specializing in threaded pipes bear car pipe end thickening (upsetting), car wire, pipe fittings manufacturing, coated with oil, corrosion, which covered by plastic so special materials and so on. In order to mass produce exclusively for petroleum, geological and chemical sector use threading pipe. Piercing using the piercing mill, in order to contact the head tube and to maintain the correct position, the end of the capillary wall thickness, as well as the roll bite into smooth tube, the piercing tip will be required before the centering tube. Refers to the so-called tube centered on the center of the front end section, along the axial direction of the tube processed into a tapered hole of a predetermined size. The actual production, the diameter is less than 90 mm in pipe wall thickness less than 5 mm, the centering can be guaranteed without mass production.
Seamless steel pipe production process in general can be divided into two kinds of cold-drawn and hot-rolled, cold-rolled seamless steel pipe production processes generally more complicated than hot-rolled, tube must first conduct a three-roll rolling, extrusion to be Sizing test, if the surface does not respond after cracking tube to be cut through the cutting machine, cut to a length of about one meter blank. Then enter the annealing process, annealing use acid pickling liquid, pickling the surface to the attention of a large number of bubbles are generated if a large number of bubbles generated description fails to reach the response of steel standards. Appearance is shorter than hot rolled seamless steel pipe seamless steel tubes, cold-rolled seamless steel pipe wall thickness generally is smaller than hot-rolled seamless steel pipe, but the surface looks brighter than the thick-walled seamless steel pipe, the surface is not too more rough, not too many glitches caliber.
Hot-rolled seamless delivery status is generally rolled after heat treatment delivery. Hot-rolled seamless quality control need to go through a strict hand-selected, after the inspection to be coated with oil, then followed by repeated drawing experiments after handling hot piercing experiments. If the perforation is too large will be expanded diameter straightening corrected. After straightening by the transfer device to the testing machine for testing experiments, the final label for specifications choreography and placed them into the warehouse.
