Medium frequency bending tube involves placing a heating coil around the steel pipe, with a gap of approximately 15mm from the pipe on all sides, slightly +2mm on the outer side and slightly -2mm on the inner side.

φ800×30 heating width approximately 55mm, φ1200×30 heating width approximately 60mm. During bending, paired with 8Mpa strong wind cooling to lower the temperature, maintaining the specified heating width temperature around 850°, allowing the steel pipe to have two cooled rounded ends.

Support it to ensure the bending section remains within a narrow width, thereby achieving a roundness that remains unchanged or very little distorted after the steel pipe is bent into shape.

Medium-frequency bending is primarily used for heating straight seam pipes and seamless steel tubes, and production can only be carried out after achieving the desired effect through medium-frequency heating. Medium-frequency induction heating bending is an advanced bending method. However, improper bending processes may lead to relaxation and damage of the metal tissue in the pipes. This damage manifests as fine grain boundary cracks, which have a negative impact on the mechanical properties and service life of the pipes. The heating range of medium-frequency bending is narrow, resulting in uneven temperatures on the inner and outer walls of the pipes, and the material is subjected to rapid cooling and heating during the bending process, which is an inherent weakness of the method.