Investigations on the impact and fracture toughness of beam welded structural steels with yield strengths from 355 to 960 MPa

摘要

Beam welding processes, i.e., laser beam welding and electron beam welding, are increasingly used to join structural steels. Welds which originate from these joining processes are known for having high weld hardness, and, in many cases, a martensitic or martensitic-bainitic microstructure in the weld seam. As these characteristics might affect the toughness behavior of those joints compared to arc welded joints, the toughness of beam-welded fine-grained steels has been investigated. Charpy impact toughness temperature curves as well as fracture mechanics tests were carried out to find a suitable T-0-T-28J-correlation. The results showed that the T-0-T-28J-correlation which is commonly used for the assessment of arc welded joints in EN 1993-1-10 does not lead to conservative results. A correlation which was originally proposed for low-carbon ultra-high-strength quenched steels was found to be more suitable.