High strength quenched and tempered (Q+T) steels for pressure vessels

In most of national European codes for pressure vessels high strength steels are penalized, often their usage requires individual material appraisals. In the new European standard for unfired pressure vessels EN 13445 these steels are also penalized. In the 'ECOPRESS' research project the Q+T-steels P500 QL2 and P690 QL2 had been investigated. The results of this project—base metal properties, formability, weldability, comparison of properties before and after forming, hardness at weld joints - are presented in this paper.