Methods of dealing with deformation problems in processing and forming of steel structures

Deformation problems in steel structure processing and forming

Causes of deformation in steel structure processing

(1) The deformation that occurs in the processing of complex steel structures mainly includes thermal deformation, cold deformation or the inability of interrelated components to be assembled into one.

(2) Thermal deformation is usually caused by improper welding process; cold deformation is caused by large volume and poor rigidity; Inaccurate line, wrong assembly sequence or deformation.

Operation method to reduce thermal deformation of welding

(1) Fixture method: use a very rigid The fixture clamps the combined weldment, controls the deformation with a forced force, and then welds it. This method is called the fixture fixing method.

The expansion force and contraction force generated inside the weldment during welding are limited by the force of the fixture, which can significantly reduce the deformation. However, there is a large internal stress inside the weldment by this method, and this method should not be used for components that require a small internal stress of the weldment.

(2) Anti-deformation method: Before the components are welded, they should be judged according to the conditions of the welded metal components. When cooling after welding, the direction of deformation and the amount of shrinkage occur, the weldment is bent or inclined in the opposite direction in advance, and after welding, due to its own shrinkage and deformation, it just returns to the predetermined shape and position. The purpose of preventing welding deformation and reducing welding stress can be achieved.

(3) The positioning control method is adopted: before the component is welded, many welding spots are used to position the welding part or its surroundings, and heavy objects can also be pressed on both sides of the welding seam. This method is called positioning control method.

(4) Welding sequence method: Correctly arranging the welding sequence is an effective method to prevent welding deformation. The law of welding deformation is that the deformation caused by the first weld is the largest, the deformation caused by each weld generally cannot cancel each other, and the final deformation direction is the same as the deformation direction caused by the first weld.