Print Email Facebook Twitter The microstructural evolution and elemental distribution of a 3rd generation 1 GPa advanced high strength steel during double pulse resistance spot welding Title The microstructural evolution and elemental distribution of a 3rd generation 1 GPa advanced high strength steel during double pulse resistance spot welding Author Eftekharimilani, P. (TU Delft (OLD) MSE-5) van der Aa, EM (Tata Steel) Hermans, M.J.M. (TU Delft (OLD) MSE-5) Richardson, I.M. (TU Delft (OLD) MSE-5) Date 2017 Abstract This paper presents the effects of double pulse resistance spot welding (RSW) on the microstructural evolution, elemental distribution and mechanical properties of a 3rd generation 1 GPa advanced high strength steel (AHSS). In order to investigate the effect of double pulsing, the steel was exposed to single and various double pulse RSW schedules. The first current pulse was applied to create the weld nugget, while the second current pulse generated a secondary weld nugget and annealed or (partial) re-melted the primary weld nugget, depending on the magnitude of the current. The effect of the second current pulse on the weld nugget and heat-affected zone characteristics was investigated using optical microscopy and electron probe microanalysis (EPMA). Optical and electron microscopy revealed that the secondary weld nugget is fully martensitic, showing a typical solidification microstructure, while the annealed zone reveals an equi-axed martensitic structure. EPMA results showed that elemental segregation has been considerably reduced in the annealed zone. Mechanical properties of the welds show that the AHSS studied is prone to weld metal failure for single pulse RSW. However, the double pulse RSW method can lead to significantly improved mechanical performance and favourable failure modes. Subject Resistance spot weldingLow alloy steelsMicrostructureSegregationMechanical properties To reference this document use: http://resolver.tudelft.nl/uuid:e0e63d47-7449-433e-b3be-5ec6a6ca19b0 DOI https://doi.org/10.1007/s40194-017-0459-4 ISSN 0043-2288 Source Welding in the World, 61 (4), 691 - 701 Part of collection Institutional Repository Document type journal article Rights © 2017 P. Eftekharimilani, EM van der Aa, M.J.M. Hermans, I.M. Richardson Files PDF art_10.1007_s40194_017_0459_4.pdf 3.94 MB Close viewer /islandora/object/uuid:e0e63d47-7449-433e-b3be-5ec6a6ca19b0/datastream/OBJ/view