The influence of in-situ alloying of electro-spark deposited coatings on the multiscale morphological and mechanical properties of laser welded Al–Si coated 22MnB5

Recent advances in mitigating fusion zone softening during laser welding of Al-Si coated 22MnB5 press-hardened steels

“…However, despite the production of defect-free joints, the FZ softening issue due to the dilution of the Al-Si coating into the molten weld pool still poses significant concerns. The remainder of this paper considers recently proposed solutions to the issue of FZ softening, particularly looking at the effect of welding Al-Si coated 22MnB5 through a pure colloidal graphite coating [44], modifying the Al-Si coating prior to welding using electro-spark deposition (ESD) [45], and welding the sample through pure Ni without prior removal of the Al-Si coating [46,47].…”

“…Other research on the subject has attempted to provide alternative methods to the colloidal graphite coating solution, like using a filler wire and a variable energy distribution laser optics [82] or modifying the laser welding processing parameters [83] but the results are underwhelming either due to the complexity of the setup or due to inadequate mechanical properties of the FZ. Therefore, an alternative approach to achieve in situ alloying in the FZ was adopted in which electro-spark deposition (ESD) was used to modify the as-received Al-Si coating on 22MnB5 PHS prior to laser welding [45]. The Al-Si coating was modified by ESD using tungsten-carbide (WC) and Inconel-625 (In625) electrodes, and the resulting changes in FZ alloying chemistry and microstructural morphology were compared to the HSBM and the ARWHS samples [45].…”

“…Therefore, an alternative approach to achieve in situ alloying in the FZ was adopted in which electro-spark deposition (ESD) was used to modify the as-received Al-Si coating on 22MnB5 PHS prior to laser welding [45]. The Al-Si coating was modified by ESD using tungsten-carbide (WC) and Inconel-625 (In625) electrodes, and the resulting changes in FZ alloying chemistry and microstructural morphology were compared to the HSBM and the ARWHS samples [45]. The study demonstrated that the introduction of in situ alloying had a substantial impact on reducing the α-ferrite phase concentration within the hot-stamped FZ of the samples that utilized modified coatings.…”

“…The study [45] analyzed the impact of in situ alloying of the FZ during laser welding of two different ESDmodified Al-Si coated 22MnB5 steels-namely, WC and In625, as shown in figure 12. The aim was to examine the effect of these coatings on the resulting microstructure and mechanical properties of the weldment.…”

“…Furthermore, this paper discusses several different methods that have been recently proposed to achieve the in situ alloying of the FZ during laser welding of Al-Si coated 22MnB5. These methods involve welding the sample directly through the Al-Si coating using secondary or modified coatings made of austenite stabilizing elements, which decreases the ferrite content and increases the strength of the weld [44,45]. In addition to the above-mentioned solutions, recent research has also explored the effect of alloying Ni with 22MnB5 on the properties of the steel [46,47].…”