S355JR is a low alloy high strength structural steel which has good welding properties. The steel is suitable for a variety of welding methods, including manual arc welding, submerged arc welding and gas shielded welding. The good welding performance is mainly due to the following reasons:
Low carbon equivalent
Carbon equivalent is an important indicator of the weldability of steel. The carbon equivalent of S355JR steel is relatively low, usually around 0.4% - 0.5%. As a result, this steel has a low tendency to form cold cracks during welding. Welding does not require high preheating temperatures or special welding techniques to achieve good welded joint quality.
Moderate content of alloying elements
S355JR contains a small amount of alloying elements such as manganese and silicon. A moderate amount of manganese can improve the strength and toughness of steel, and the toughness of the weld heat affected zone has a certain improvement. Silicon can increase the strength of steel, but the content is controlled within a certain range, will not have too much adverse effect on welding performance.
Good plasticity and toughness
The steel itself has good plasticity and toughness, which makes the welded joints better able to adapt to deformation when subjected to external forces, reducing the possibility of weld cracks and brittle breaks. After welding, the welded joints can maintain good mechanical properties, match the base material and meet the use requirements of the structure.
