Shear tension strength of resistant spot welded ultra high strength steels

• Published in: Thin-walled structures Vol. 142; pp. 64 - 73
• Main Authors: Varbai, Balázs, Sommer, Christina, Szabó, Mihály, Tóth, Tamás, Májlinger, Kornél
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2019
• Subjects: Advanced high strength steel AHSS; Resistance spot welding RSW; Shear tension strength STS; Thin steel sheets; Ultra high strength steel UHSS; Ultra high strength steel UHSS; Shear tension strength STS; Resistance spot welding RSW; Advanced high strength steel AHSS; Thin steel sheets
• ISSN: 0263-8231; 1879-3223
• DOI: 10.1016/j.tws.2019.04.051

To reduce self-weight of thin-walled structures like car bodies, the use of ultra high strength steels (UHSS) is beneficial. Therefore, three UHSS steels with tensile strength (Rm) ≥ 1500 MPa were resistance spot welded in different combinations successfully. The obtained shear tension strength (STS) values were evaluated with significant amount of literature data, and a new correlation is proposed for the minimum required STS for UHSSs with Rm ≥ 1340 MPa. With this equation the design is more permissive for parts with shear loading, enabling less welded points for the designer and subsequent faster production of such resistance spot welded parts. [Display omitted] •Ultra high strength steel (UHSS) sheets with tensile strength > 1500 MPa were resistance spot welded successfully.•The homogeneous and dissimilar joints were optimized for maximal shear tension strength (STS).•All the joint combinations of UHSSs had beneficial button pull fracture.•All the joints had significantly higher STS than anticipated according AWS D 8.1 standard.•A new correlation for minimal STS values for UHSSs joints with higher tensile strength than 1340 MPa is proposed.