Weldability of Hsla Steels in Relation to Appropriate Toughness Requirements for Use in Safe and Economic Steel Construction

Research efforts in the development of high strength steels during the past 4 decades have led to a bundle of new steels which provide not only high strength to the designer, but also have excellent toughness, low transition temperature behavior in view to cold climate application and good weldability. However, application of such modern steels in many cases seems to be restricted which means that advantages resulting from light weight design such as lower working costs, lower transportation weights and lower energy consumption cannot be fully realized. Reasons for that are manifold and can either be technically justified (e.g. for highly fatigue loaded structures as bridges) or may result from lack of design knowledge, fabrication knowledge with respect to weldability and heat treatment, a diffuse understanding of the toughness issue and finally lack of appropriate standards.