The daily use S355J2H seamless steel pipe needs to do some cutting treatment and heat treatment, what are the reasons why S355J2H seamless steel pipe needs to be treated?

Cutting treatment of S355J2H seamless steel pipe: after S355J2H seamless steel pipe is straightened, initial inspection and soot blowing shall be carried out to determine the cutting head and tail length. The purpose of S355J2H seamless steel pipe cutting is to remove the ends with cracks, knots, scars, tears and uneven wall thickness, so as to obtain the required fixed size S355J2H seamless steel pipe. In addition, the defects that are unqualified and difficult to be rescued after inspection are removed, such as internal folding, internal scab, serious wall thickness inhomogeneity, etc. Generally, the former is cut off on the operation line, while the latter is off-line.

Control of holding time during heat treatment of S355J2H seamless steel pipe: during heat treatment of S355J2H seamless steel pipe, the holding time shall ensure that the steel pipe in the furnace can be completely burnt through, the temperature is uniform, and the structure transformation shall be completed, so as to obtain uniform structure and performance. Generally, increasing the heating temperature can shorten the holding time. During low temperature annealing, including softening, stress relief and recrystallization annealing, the closer the annealing temperature is to the lower critical point A1, the faster the recovery of S355J2H seamless steel pipe is, the more complete the elimination of work hardening is. Therefore, the holding time can be appropriately shortened.