Method of Reducing Welding Deformation for Q345R Steel

The methods to reduce welding deformation during welding of Q345R steel mainly include:
1. Reasonable assembly sequence and welding sequence. To correctly select the assembly and welding sequence of Q345R steel, the following principles should generally be followed: a. The weld seam with large shrinkage is welded first, because the weld seam welded first is less hindered when it shrinks, so the stress is smaller; b. Adopt symmetrical welding , which greatly reduces the re-deformation of Q345R steel after welding. For symmetrical welds, it can be welded symmetrically at the same time, at least two people, and large structures can be welded by multiple people at the same time, so that the welds to be welded are mutually restricted. The structure does not produce overall deformation; c. When welding the long weld seam of Q345R steel, the welding sequence such as symmetrical welding, gradual back welding, split middle and gradual back welding, and skip welding should be adopted.

2. Reduce the size and quantity of Q345R steel welds as much as possible.

3. Anti-deformation method. The anti-deformation method is a method often used in production. It pre-adds an opposite deformation during assembly according to the size and direction of the welding deformation estimated in advance, so that it can offset the deformation produced by Q345R steel welding.

4. Rigid fixation method. This method is to fix the Q345R steel to limit the welding deformation without reverse deformation. This method is more effective for angular deformation and wave deformation.