Large Diameter Seamless Steel Pipe and Small Diameter Seamless Steel Pipe

Small diameter steel pipe, can be called small diameter seamless steel pipe, small diameter seamless steel pipe can also be divided into: seamless small diameter steel pipe and straight seam (also known as welding) small diameter seamless steel pipe, general in the steel pipe diameter of 89mm below, 4mm or more; can be collectively referred to as small diameter seamless steel pipe.

Large diameter seamless pipe refers to the pipe diameter greater than 325mm, the main production process for the hot-rolled large diameter seamless steel pipe and hot expanded diameter seamless steel pipe, thermal expansion of seamless steel pipe can produce non-GB size, we often say that the thermal expansion pipe, the density is relatively low but the strong contraction of the steel pipe with a slim rolling method or drawing method to expand the diameter of a pipe finishing process.

Smls pipe according to the production method can be divided into different hot-rolled pipe, cold-rolled tube, cold-drawn tube, extrusion pipe, hot-rolled seamless pipe is generally produced in the automatic rolling mill, solid tube inspection and removal of surface defects cut into the required length, in the tube tube perforation end of the center of the center, and then sent to the heating furnace, perforation in the piercing machine, at the same time continuous rotation and forward, in the roll and the role of the head, cavity called capillary, and then sent to the automatic rolling mill to continue rolling through the whole machine are the whole wall thickness, the sizing machine to achieve the specifications, the use of continuous rolling mill production of hot-rolled seamless steel pipe is a more advanced method, if you want to get smaller and better quality seamless pipe, cold rolling, cold drawing or cold combination of the two methods must be cold rolling is usually carried out in the two-roll mill, steel pipe in the variable section round hole and not moving Of the conical head of the ring formed by the rolling, cold drawing is usually carried out in a single chain or double chain cold drawn machine, the extrusion method is about to heat a good tube placed in a closed extruded cylinder piercing rod with the squeeze bar to move together to squeeze member is extruded from the die hole smaller, produce smaller diameter steel pipe in this method. Large diameter seamless steel pipe specifications for the maximum size of 325mm-1220mm thickness of 120mm, thermal expansion of seamless steel pipe can produce non-national standard size, thermal expansion of seamless pipe is that we often say that the thermal expansion pipe, the density is relatively low but strong contraction steel pipe with a rolling method or drawing method to expand the diameter of a pipe pipe finishing process.