About flux-cored wire fusion welding, in the weld and its heat-affected zone are large residual stress, the existence of residual stress will lead to deformation, cracking and reduce the bearing capacity of the welded components; at the same time, in the weld toe area there are also pits, residual height, bite edge stress concentration; and the weld toe slag defects, microcracks and the formation of early crack sprouting source. As a result of residual tensile stress, stress concentration and the influence of the source of cracking, the fatigue life of the welded joint is greatly reduced.
After the overlay weld wire residual stresses are concentrated in the vicinity of the weld, when the weld residual stresses are superimposed with the working stresses of the load, the value exceeds the yield limit of the material, the workpiece will produce welding deformation near the weld, fracture and other phenomena. The study of the effect of residual stress not only considers the size of its value, and the direction of the residual stress is also an important factor, using the blind hole method residual stress detector can measure the size and direction of the value of residual stress in welding. When analyzing the effect of residual stress, even if the residual stress value of a welded component is well below the yield limit of its material, if there is a severe stress concentration, then the welded component will undergo permanent plastic deformation due to the release of residual stress during its transportation and use.
The main methods of reducing deformation in cladding welding are as follows:
1. Choose a reasonable welding sequence.
2. Use symmetrical welding seams (such as I-beam cross-section) as far as possible.
3. The use of anti-deformation method.
Wear-resistant wire welding process to control deformation of the main measures:
1. The use of anti-deformation.
2. The use of small hammer hammering intermediate welding channel.
3. The use of a reasonable welding sequence.
4. The use of rigid fixation of work jigs.
5. Analysis of rebound constants.
Post time: Sep-30-2021