Symmetric welding sequence
Symmetrical welding sequence means you weld alternately from the center outward or mirror-symmetrically to the neutral fiber. This prevents asymmetric distortion and thermal expansion.
Physical-Chemical Mechanism of Action
In symmetrical welding sequence, the center of the part is used as a neutral point from which welding proceeds alternately outward. This ensures that thermal expansions are distributed evenly and no asymmetrical distortion occurs.
Metallurgical Relevance & Welding Risks
If the welding sequence is not symmetrical, thermal expansions can be distributed unevenly. This leads to asymmetrical distortion and increases the risk of cracks or stress areas in the weld.
Shop Practice & Instructions
To ensure a symmetrical welding sequence, always start with the center of the part and work alternately outward. Make sure the temperature distribution is even and no uneven expansions occur. Use the same parameters for each weld pass, such as arc time and current.