Seamless steel pipe crack analysis are as follows:
First, the nonuniformity of the structure is the cause of the tube.
Second, the finished annealing temperature is suitable. Perforated heating temperature 1180 ~ 1230 ℃, low, which is the temperature of carbon steel, take 1230-1250, is appropriate. 35min is the heating time or furnace time? Furnace time is generally more than 60min.
Third, the crack may be the reason, I have done a number of tests. The result is tube (round) of the majority, the internal contains more cracks, inclusions, air bags and so on.
Perforation temperature, process adjustment can not be ignored, if the perforation temperature is low, improper adjustment, can also cause tearing of the capillary tube internal organization.
