Welding Sequence
The welding sequence determines the order and timing of welding passes in complex components to control shrinkage stresses and avoid distortion.
Physical-Chemical Mechanism of Action
The welding sequence affects the thermal expansion and contraction of the metal during welding. Each weld pass heats up and cools down, causing stresses. The correct sequence minimizes these stresses through controlled cooling.
Metallurgical Relevance & Risks in Welding
An incorrect welding sequence can lead to high shrinkage stresses and cracks, especially in thick components or with dissimilar materials. This can cause distortion and reduce the component's service life.
Workshop Practice & Action Instructions
When planning the welding sequence, keep the following points in mind:
• Start with the outer passes and work inward.
• Avoid welding adjacent passes simultaneously to minimize stresses.
• Make sure each weld pass has cooled sufficiently before starting the next.
• Use stress relief measures such as stress belts or clamping screws if needed.