Tell You About The Seamless Steel Pipe Production Process
Today, mainly to tell you about the seamless steel pipe production process, there are two kinds of hot-rolled and cold-rolled, the following together to find out about it
1. Hot-rolled (extruded seamless steel pipe): round tube billet - heating - perforation - three roll skew rolling, continuous rolling or extrusion - off tube - sizing (or reducing) - cooling - straightening - water pressure test (Or flaw detection) - mark - storage. Seamless steel pipe is made of steel ingot or solid tube through the perforated tube, and then made by hot rolling, cold or cold. The specifications of the seamless steel pipe are indicated by the outer diameter * wall thickness mm. Seamless steel pipe hot rolling and cold rolling (dial) seamless steel pipe two categories. Hot-rolled seamless steel pipe is divided into general steel pipe, low and medium pressure boiler steel pipe, high pressure boiler steel pipe, alloy steel pipe, stainless steel pipe, oil cracking pipe, geological pipe and other steel pipe. In addition to the general steel pipe, low pressure boiler steel pipe, high pressure boiler steel pipe, alloy steel pipe, stainless steel pipe, oil cracking pipe, other steel pipe, but also includes carbon thin-walled steel pipe, alloy thin-walled steel pipe, Stainless steel pipe, shaped steel pipe. Hot-rolled seamless pipe diameter is generally greater than 32mm, wall thickness 2.5-75mm, cold-rolled seamless pipe diameter can be 6mm, wall thickness to 0.25mm, thin-walled tube diameter to 5mm wall thickness of less than 0.25mm, cold Rolling ratio is higher than that of hot rolling.
General use of seamless steel pipe is 10,20,30,35,45 and other high-quality carbon steel 16Mn, 5MnV and other low-alloy structural steel or 40Cr, 30CrMnSi, 45Mn2, 40MnB and other synthetic steel made of hot-rolled or cold-rolled. 10,20 and other low-carbon steel seamless steel pipe is mainly used for fluid pipeline. 45,40Cr and other carbon steel made of seamless pipe used to manufacture mechanical parts, such as cars, tractors force parts. Generally use seamless steel pipe to ensure strength and flattening test. The hot-rolled steel pipe is delivered in a hot-rolled state or a heat-treated state; the cold-rolled steel is delivered in heat-treated state.
Hot rolling is the high temperature of the workpiece, so the deformation resistance is small, can achieve a large amount of deformation. For example, the thickness of continuous casting slab is about 230 mm, and after rough rolling and finish rolling, the final thickness is 1 to 20 mm. At the same time as the thickness of the steel plate is small, the size of the precision requirements are relatively low, not easy to plate shape problems to dominate the convex. For the organization has the requirements, generally controlled by rolling control to achieve, that is, control the rolling of the rolling temperature, finishing temperature.
2. Cold-rolled seamless steel pipe: round tube - heating - perforation - head - annealing - pickling - oil (copper) - multi-pass cold drawn (cold) - billet - heat treatment - straightening - water pressure Test (Flaw Detection) - Marking - Storage.