Weld Bead Sequencing
The weld bead sequence defines how and where the individual layers are placed in multi-pass welding. It controls the thermal reduction of stresses and improves the microstructure.
Physical-Chemical Mechanism of Action
The sequence of weld beads influences the thermal deformation of the material during the welding process. A deliberate sequence of layers achieves a uniform thermal stress distribution, leading to optimal stress relief.
Metallurgical Relevance & Welding Risks
An incorrect weld bead sequence can lead to uneven cooling and thus to stress buildup. This can result in cracks, distortion, or poor toughness of the material. Furthermore, a faulty sequence can alter the microstructure, impairing mechanical properties.
Workshop Practice & Instructions
For multi-pass welds, it is crucial to follow the weld bead sequence exactly. This means each individual pass must be placed and welded in the specified order. Temperatures and times for each welding step must be adhered to ensure an optimal thermal stress distribution. If you have questions about the correct sequence, consult the material manufacturer or the material data sheets.