Symmetric welding sequence
Symmetrical welding sequence is a timed weld build-up on both sides of a neutral axis to compensate for transverse shrinkage. This prevents stresses and cracks.
Physical-Chemical Mechanism of Action
Symmetrical Welding Sequence ensures that the weld is deposited on both sides of a neutral axis simultaneously and in the same time. This leads to symmetrical cooling and minimizes transverse shrinkage.
Metallurgical Relevance & Welding Risks
Without a symmetrical welding sequence, unequal cooling times can cause stresses in the material structure, leading to cracks and distortion. A symmetrical sequence prevents these issues and increases the toughness of the weld.
Shop Practice & Instructions
To ensure a symmetrical welding sequence, both sides of the joint must be welded at the same time. This requires precise timing and often the use of two welding torches or machines. The cooling time should also be symmetrical to avoid stresses.