Low carbon steel welding process

Low carbon steel has a carbon content of ≤0.25% and good plasticity. Generally no hardening tendency, insensitive to welding process, good weldability. No special process measures are required when welding such steels, and usually no heat treatment is required after welding (except for electroslag welding).


For low-carbon steel structures with a thickness of more than 50mm, high-current multilayer welding is generally used, and internal stress annealing is eliminated after welding. When the structure with high welding stiffness is large in low temperature environment, the temperature difference between parts of the weldment is large, and the deformation is limited. Large internal stresses are prone to occur during welding, leading to structural cracking. Therefore, preheating should be performed before welding.


Low carbon steel can be welded by various welding methods. The most widely used are arc welding, submerged arc welding, electroslag welding, gas shielded welding and resistance welding.


When fusion welding is used to weld structural steel, the choice of welding materials and processes should mainly ensure the strength of the welded joints and workpiece materials. Electrode arc welding is generally a low-carbon steel structure. E4313 (J421), E4303 (J422), and E4320 (J424) electrodes can be selected. When welding dynamic structures and complex structures, E4316 (J426), E4315 (J427) or E5015 (J507) electrodes should be used. Submerged arc welding generally uses H08A or H08MnA wire, flux 431.