The weldability of steel refers to the ability to produce a welded joint with good properties under specific welding process conditions. Weldability can be categorized into two types: weldability during the welding process and weldability in terms of service performance. Weldability during the welding process refers to the susceptibility of the weld metal and the adjacent base metal to the formation of hot cracks during welding, or cold cracks (shrinkage cracks) during the cooling phase.
Good weldability means that, under specific welding process conditions, neither the weld metal nor the adjacent base metal develops any cracks. Weldability in terms of service performance relates to the impact toughness of the weld and the ductility within the heat-affected zone (HAZ); it requires that the mechanical properties of the steel in the weld and the heat-affected zone be no lower than those of the base metal. In my country, test methods are employed to evaluate both the weldability during the welding process and the weldability in terms of service performance.