Hot rolled steel pipe is mainly used for oil and gas transmission line, and its specification is expressed by outer diameter * wall thickness.. Hot rolled tube has single side welded and double side welded, welded pipe should guarantee the water pressure test, the tensile strength and cold bending property of the welded pipe should be accord with the regulations.. Hot rolled steel pipe is by high frequency welding units will be a specification of strip steel is rolled into a cylindrical and straight seam welded steel pipe. The shape of hot-rolled steel pipe can be circular, or square or irregular, fixed diameter rolling straight seam pipe depends on after welding.
Pressed by the opening with a straight off after molding, high frequency welding of steel tube rolling is by using the alternating current skin effect and proximity effect, steel strip (strip) by rolling, the formation of a section of circular tube in tube bloom near the induction coil near the center of rotation or a set of impedance (bar), the impedance tube openings form a electromagnetic induction loop in the skin effect and proximity effect, tube at the edge of the powerful and concentrated heat effect, make the weld edge rapidly heated to welding temperature and extrusion, molten metal intergranular bonding, straight seam pipe cooling after the formation of a firm butt weld.
Hot rolled steel pipe weld shrinkage induced local strain often reaches the yield point strain several times, much larger than the load induced strain; uneven cooling caused by the residual stress. Residual stress is in no external force under the action of internal self equilibrium stress and various section of hot-rolled steels have this kind of residual stress and general steel section size is larger, residual stress is larger. Although the residual stress is self balanced, but still have a certain influence on the steel structure under external force performance. Such as deformation, stability, fatigue and other aspects may have a negative effect.
Hebei Shengtian group seamless steel tube Co., Ltd. the main products are: in low pressure boiler seamless steel pipe, oil casing with seamless steel tube, ship with seamless steel pipe, seamless steel pipe conveying fluid, petroleum cracking with seamless steel tube, chemical fertilizer equipment with seamless steel tube, seamless steel tube structure, hollow pumping rod with seamless steel tubes and other eight series. According to GB.ASTM.API5L.API5CT..DIN.JIS. and other standards of production 10mm-820mm, wall thickness 1.5mm-30mm seamless steel tube. Products are sold to the country and exported to Southeast Asia. Middle East.. In the domestic and foreign markets enjoy a high reputation.