Method of making alloy pipe fittings

After the hot rolling and sizing process is finished, the pipe making method and bending a, the unevenness, usually the steel pipe should be turned around naturally. However, in the parts of the slide, chain or screw that come into contact with the steel pipe, water from these parts can also be sprayed onto the pipe. The part where the axial and circumferential velocities of the alloy pipe are not uniform shrinks sharply, and when the remaining red-hot part shrinks, the existing part will be pulled over. Since this shrinkage is a complex deformation, it forms a minor bends. In addition, strictly speaking, due to the difference of the speed in the national circumferential direction, the hot-worked steel pipe inevitably produces different degrees of deformation. b. Whether the bending produced on the sizing machine is hot working or cold working, if the line between the frames of the sizing machine is inconsistent, as shown in Figure 2-2, just like the rough bending machine, make the steel pipe a little bit in the same direction Bend down. Such bends are called "big bends". Now using this phenomenon in turn, the large bending produced in the d section can be straightened by the sizing machine. When the small bending hot-rolled steel pipe is produced at the end of the pipe, because the head and tail are unstable, the thickness of the wall is not stable. , The outer diameter is abnormal, and there are many cases of bending.

During the operation of the transfer roller table, the pipe end may be bent, etc., and the pipe end may be deformed. In addition, as shown in Fig. 23, if there is an offset with respect to the roll line between the sizing machine stands, the pipe and the roll cannot be contacted at the same instant. The pipe is subjected to bending and forging. Although the diameter is reduced on the sizing machine, there is no tension at the front end and rear end of the pipe, so the bending remains. This kind of bending is called pipe end bending. Once freed from the shackles of life, that kind of curvature becomes a big curvature with the continuation of time. More strictly speaking, the deformation also occurs in the national circumference direction, making the alloy pipe fittings not round, and the bending caused by the tube blank. If the chemical composition of the tube blank (round steel or strip steel) segregates, the hot workability and The difference in speed will cause the steel pipe to form a large bend. Because the strip steel has a bending called warpage, the steel pipe made of strip steel cannot be formed uniformly and smoothly, and the steel pipe will be greatly bent or twisted. "Others are cold drawn. During processing, due to the deviation of the draft line and the clamp line of the pulling trolley and the deviation from the tube blank line, the section deformation will be uneven, and a large bending will occur from the surface. The effect of bending a, when the steel pipe is sent for finishing, due to the steel pipe It is round and can rotate by itself, so it has special advantages when handling.