How to handle deformation of stainless steel tower sections?

Deformation of stainless steel tower sections requires a graded correction strategy based on the type and degree of deformation. For localized indentation deformation, hydraulic jacks combined with arc-shaped pads can be used for cold straightening. The force application point must avoid the weld area, and the straightening amount should be controlled within the elastic deformation range (not exceeding 3% of the wall thickness). For overall bending deformation, a multi-point synchronous lifting system should be used, with 6-8 hydraulic cylinders arranged circumferentially around the tower section. The deformation recovery should be monitored using a strain gauge, and straightness testing should be performed after straightening (deviation ≤ 1‰ of tower section height). Direct force should be strictly prohibited on deformation in the weld area; local heating should be used for auxiliary straightening, with the temperature controlled below 650℃ and monitored in real time with thermocouples to avoid sensitization of austenitic stainless steel.

When severe deformation leads to material yielding, the deformed section must be removed and replaced with a new section. Stress analysis should be performed before cutting to determine the cutting sequence. Plasma arc cutting should be used, leaving a 10mm allowance, and subsequent machining should ensure bevel accuracy. Repair welding must employ a narrow-gap welding process, with interpass temperature not exceeding 150℃. Immediate post-weld solution treatment (water quenching at 1050℃) is required to restore material properties. All straightening work must be followed by 99.99% penetrant testing (PT) and local radiographic testing (RT), with acceptance standards conforming to Class II requirements of NB/T 47013. For tower sections subject to repeated deformation, annular reinforcing rings should be added or the wall thickness increased to enhance deformation resistance. A hydrostatic test, 1.25 times the design pressure, is then required to verify structural integrity.