Analysis of crack reason of seamless steel tube

 　　What are the main factors that cause seamless steel pipe cracking? There are mainly the following points:

　　1. Raw material selection

　　In order to save costs, some seamless steel pipe manufacturers will use round steel produced by small steel plants for processing, but the round steel produced by these small steel plants will contain many impurities, bubbles, interlayers, pores, etc., which will easily cause cracks after post-processing. problem.

　　2. Inadequate heat treatment temperature control

　　Small manufacturers do not have professional production experience and technology. Workshop workers cannot guarantee whether the heat treatment of the steel pipe is in place based on the heating temperature and duration alone, and the heat treatment will change the mechanical properties of the steel pipe. However, general manufacturers do not have clear indicators for different steel grades, wall thicknesses, mechanical properties, etc., and no testing equipment to determine whether the pipe has reached the performance indicators required by the customer.

　　3. Straightening strength

　　Straightening is equivalent to secondary deformation. Two-way force is applied during straightening. If the operator is not experienced enough, the straightening force is too strong, and the thick-walled pipe will cause internal damage and cracks if the strength of the thick-walled pipe is not well controlled. This is also the reason for the cracking of the steel pipe in the later stage.

　　4. Drawing deformation

　　If the drawing deformation is too large, steel pipe cracks will also be formed, causing the steel pipe to crack during the later processing. Bright tube has low elongation, generally 7-8%, large deformation, low elongation; small deformation, high elongation. Some small manufacturers cut corners and cut corners to save craftsmanship. The three deformations were changed to two, which expanded the deformation and caused excessive stress to cause cracking.

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