Heat expansion seamless steel pipe

We often say that the heat expansion seamless pipe refers to a steel pipe with a relatively low density but a strong shrinkage. (Seamless steel pipe) can be simply referred to as a thermal expansion pipe. A roughing finishing process for expanding the diameter of a pipe by a cross-rolling method or a drawing method. In a relatively short period of time, the steel pipe is thickened, and non-standard, special-type seamless pipes can be produced, and the cost is low, and the production efficiency is the development trend in the international rolling pipe field.

The two-step propulsion pipe expanding machine adopts the taper die expanding technology, the digital intermediate frequency induction heating technology and the hydraulic technology in one machine, with its reasonable process, low energy consumption, low construction, Good product quality, wide range of raw materials and product specifications, flexible, easy to change, low-input production batch adaptability, replacing the traditional pull-type expansion technology of the steel pipe industry.

What are the precautions for the production of thermal expansion seamless pipes:
1. When the hot-expanded pipe material is subjected to the initial cutting head and tail after straightening, it is only necessary to cut the shrinkage and the empty-drawn section and the cracked part of the tail, and it is not possible to cut; the end face should be flat and not skewed;

2. The finishing class shall carry out surface inspection on the inspection rig on the expansion of the pipe material. The outer fold, the inner fold, the crack, and the outer knot are small and the depth is shallow, and the outer fold is more or deeper. The direct judgment of the inability to repair can not be used as the expansion pipe; after the grinding, the wall thickness exceeds the negative deviation and is repaired and smoothed;

3. After the thermal expansion operator has checked the inner and outer surfaces of the pipe, it is found that the defects such as the outer folds and cracks that have been missed are repaired by the grinding wheel, and the depth of the grinding is filled and smoothed by electric welding;

4. When encountering the rigid head tube, mark it on the rigid part of the head. During the expansion process, when the jaw is coming to the end, slow down the speed and increase the temperature;

5. After the expansion is completed, the inner and outer surfaces should be inspected. The unremoved defects should be marked on the steel pipe and recorded in the production record; the grinding can be repaired and then transferred to the annealing furnace;

6. After each expansion of a steel pipe, the expanded wall thickness shall be measured, and the specifications shall be determined according to the standard requirements and the production record shall be made.