1. Try not to arc welding. New high-strength steel wire application of trace alloying elements to promote the formation of acicular ferrite and pro-eutectoid ferrite precipitation inhibition, a substantial swing arc, will change the ferrite morphology, and precipitation in the intergranular harmful organization. Therefore, the welding arc as far as possible not to ensure good performance of the weld.
2. Protective gas requirements. The new high-strength steel wire as far as possible the use of argon-rich mixture of gas welding, in order to ensure the transition of alloying elements and get a good microstructure.
3. Preheating and post-weld heat treatment. For Q550 above the level of high-strength steel, preheating and post-weld heat treatment is necessary, but also to control the welding process of the inter-channel temperature. If necessary, the use of more than welding.
4. The welding process. Using multi-channel multi-channel dislocation welding, in order to obtain an excellent welding joints. Arc and arc should be staggered off more than 50mm, to avoid the stress concentration at the arc and arc.
5. Welding material selection. For the positioning welding and backing welding, using a base metal strength lower than the level of welding wire, the effect will be better. Such as GHS-70 (GB / T8110, ER69-G) for Q690, GHS-80 (GB / T8110, ER76-G) for filling and capping.
6. A reasonable welding sequence. It is necessary to prevent the occurrence of large welding deformation, but also to control the welding stress, according to the workpiece structure, develop a reasonable welding sequence.
