Author Affiliations
State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology,Harbin, Heilongjiang 150001, Chinashow less
Fig. 1. Microstructure of ST12 galvanized steel sheet matrix and appearance of zinc coating. (a) Microstructure of matrix; (b) appearance of zinc coating
Fig. 2. Schematic of experimental setup and welding path. (a) Experimental setup; (b) welding path
Fig. 3. Schematic of shear tensile specimen. (a) Spot welding; (b) 30 mm laser welding; (c) 15 mm laser welding
Fig. 4. Influence of spot welding velocity on spot weld morphology. (a) 125 mm/s; (b) 105 mm/s; (c) 75 mm/s
Fig. 5. Influence of inter-sheet gap on spot weld morphology
Fig. 6. Influence of inter-sheet gap on spot weld diameter and underfill size
Fig. 7. Fe and Zn elements distribution on the edge of spot weld prepared at different inter-sheet gaps
Fig. 8. Load-displacement curves and macro-profiles of spot weld prepared at different inter-sheet gaps and macro profiles of failure wendment. (a) Load-displacement curves ; (b) macro profiles of failure weldment
Fig. 9. Failure modes. (a) Partial thickness-partial pullout; (b) pollout failure
Fig. 10. Maximum load of spot weld prepared at different inter-sheet gaps
Fig. 11. Fracture profiles. (a) 0.1 mm inter-sheet gap; (b) 0.6 mm inter-sheet gap; (c) enlarged image of pore region c; (d) enlarged image of region d in Fig.11 (c)
Fig. 12. Process parameter of different welding methods and corresponding cross-section of weldments
Fig. 13. Load-displacement curves of weldment welded by different methods
Materialthickness /mm | Yieldstrength /MPa | Tensilestrength /MPa | Mass fraction /% |
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C | Si | Mn | P | S |
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1.8 | 130--260 | ≥270 | ≤0.1 | - | ≤0.5 | ≤0.035 | ≤0.035 |
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Table 1. Mechanical properties and chemical composite of ST12 galvanized steel sheet
Location | Mass fraction /% |
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Fe | Zn | |
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A* | 14.36 | 85.64 | B* | 22.34 | 77.66 | C* | 17.86 | 82.14 |
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Table 2. Chemical composition of fracture surface for 0.1 mm inter-sheet gap
Welding method | Maximum load /N |
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Resistance spot welding | 14.40 | Laser screw welding | 15.72 | 30 mm laser welding | 16.57 | 15 mm laser welding | 8.06 |
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Table 3. Maximum load of weldment welded by different methods