Because the welding deformation of steel structure is inevitable in welding production, one or several methods should be selected to control the deformation according to the specific form of welding structure in steel structure production. Fuyang steel structure project will specifically introduce the following methods:
(1) Attach importance to steel structure design.
Reasonable steel structure design and weld layout play a very important role in preventing and reducing welding deformation. In the design, on the basis of saving materials, convenient manufacture and safe use, we should also pay attention to: reducing the number and length of welds as much as possible; Welds should be arranged symmetrically as far as possible, and the welds should be symmetrical with respect to the neutral axis of the steel structure section; Try to use smaller weld groove and size; Simple welding fixtures and tooling are used in production.
(2) Reserve the weld shrinkage allowance when blanking.
In order to compensate for the linear shortening of weld after welding, Fuyang steel structure project can estimate the weld shrinkage by experimental method or reserve shrinkage allowance in advance when preparing materials. Because the shrinkage of weld is related to many factors, it is difficult to determine the shrinkage by calculation, so we can only rely on process tests and accumulate a lot of data to estimate the deformation.
(3) Inverse deformation method
In order to offset the welding deformation of steel structure, when assembling weldments, the weldments are artificially deformed in the opposite direction to the welding deformation in advance. This method is called reverse deformation method. Due to the change of welding conditions, the deformation of welding structure is different. Therefore, how to determine the deformation resistance in actual production is an extremely important and complicated problem. Usually we can only rely on a lot of experimental data or the accumulation of practical experience. Generally speaking, when the plates are butt welded, the angular deformation is related to the thickness, width and weld energy of the plates.
(4) Choose a reasonable assembly and welding sequence.
The steel structure is properly divided into blocks, assembled and welded separately, and then welded into a whole, so that asymmetric welds or welds with large shrinkage can shrink freely without affecting the whole structure. According to this principle, the production of complex and large-scale welded structures is not only conducive to controlling welding deformation, but also conducive to expanding the working face and shortening the production cycle.
(5) Rigid fixation method
Generally speaking, the welding deformation of weldments with high rigidity is small. The method of reducing welding deformation by imposing rigid constraints is called rigid fixation method or inhibition method. Rigid fixation method can use welding fixture to press heavy objects on weldments or fix weldments on rigid platforms, which can effectively reduce welding deformation. However, it must be pointed out in Huaibei steel structure project that rigid fixation method is adopted after welding. In general, there will be a large welding internal stress in the weldment. Therefore, it is not appropriate to use rigid fixation to control welding deformation for workpieces or welding materials with large crack tendency.
The above is Fuyang steel structure project and how to avoid welding stress and deformation of steel structure as much as possible. I hope it will help everyone! This article comes from Anhui Ganda Steel Structure Co., Ltd.:/.