At present, China's large-diameter seamless steel tubes, the main production process for hot-rolled large-diameter seamless steel tubes and hot expanded seamless steel tubes, hot-rolled seamless steel tubes can produce non-GB size, thermal expansion seamless tube is what we often say hot Expanded pipe, a relatively low density but strong contraction of the pipe using the oblique rolling method or drawing method to expand the pipe diameter of a barn finish rolling process. The thickening of steel pipes in a short period of time can produce non-standard and special models of seamless pipes with low cost and high production efficiency. It is the current trend in the field of international pipe rolling.
For GB5310 steel pipe with outer diameter greater than or equal to 76 and wall thickness ≥ 14mm, Charpy V-type longitudinal impact test shall be carried out at 20°C; the average value of impact energy of the three samples shall not be lower than 40J, allowing one sample The impact energy is lower than the average but not lower than 70% of the average. Outer diameter> 219.1mm, and wall thickness ≥ 25mm steel tube can be used instead of the longitudinal mechanical properties test. The Charpy V-type transverse impact test was performed at 20°C, and the large-diameter tube was more convenient for the transverse mechanical test. Application
The scope of use includes general structural and mechanical structures, and a large number of structural tubes used in construction, machinery, transportation, aviation, oil extraction and other industries Dimensional tolerance