When is it more appropriate to use a welding hammer to hammer?
Hammering cannot occur in the base weld or the cover layer. Why? If not, when is it right to implement hammering?
Hammering will cause the weld metal to expand laterally, so that the tensile stress inside the weld is offset during cooling. Therefore, hammering can control the deformation of the weld metal, stabilize the size, eliminate welding residual stress, and prevent welding cracks. Hammering must be performed on each weld to be effective. The effectiveness of hammering decreases as the thickness of the weld increases or hammering is performed after welding multiple layers.
The first weld is relatively thin and cannot withstand heavy hammering, while the cover layer weld will be cold-worked and hardened by hammering, and there is no possibility of heat treatment by the next layer of weld. Therefore, the first layer of weld and the cover layer weld should not be hammered.
