• Chinese Journal of Lasers
  • Vol. 50, Issue 12, 1202104 (2023)
Zhao Liu1, Lihua Pan2, Xiaoqiang Li2, Jian Gao2, and Ke Zhang1、*
Author Affiliations
  • 1School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
  • 2Shanghai Space Propulsion Technology Research Institute, Shanghai 201100, China
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    DOI: 10.3788/CJL221499 Cite this Article Set citation alerts
    Zhao Liu, Lihua Pan, Xiaoqiang Li, Jian Gao, Ke Zhang. Study on Microstructure and Properties of Laser-Welded 30Cr3 Ultra-High-Strength Steel Joints Based on Weld Penetration Mode[J]. Chinese Journal of Lasers, 2023, 50(12): 1202104 Copy Citation Text show less
    Microstructures of 30Cr3 base metal. (a) Optical and confocal images; (b) SEM image; (c) IPF; (d) EDS plane distribution of Cr element
    Fig. 1. Microstructures of 30Cr3 base metal. (a) Optical and confocal images; (b) SEM image; (c) IPF; (d) EDS plane distribution of Cr element
    Schematics of test devices. (a) Observing dynamic behavior of molten pool; (b) observing dynamic behavior of keyhole
    Fig. 2. Schematics of test devices. (a) Observing dynamic behavior of molten pool; (b) observing dynamic behavior of keyhole
    Dynamic behaviors of keyholes under different weld penetration modes. (a1)-(a5) Keyhole unpenetrated fusion mode; (b1)-(b5) keyhole critical penetration fusion mode; (c1)-(c5) keyhole stably penetrated fusion mode
    Fig. 3. Dynamic behaviors of keyholes under different weld penetration modes. (a1)-(a5) Keyhole unpenetrated fusion mode; (b1)-(b5) keyhole critical penetration fusion mode; (c1)-(c5) keyhole stably penetrated fusion mode
    High speed photographic images of molten pool during welding process under different laser powers. (a) 3.4 kW; (b) 3.5 kW; (c) 3.6 kW; (d) 3.7 kW
    Fig. 4. High speed photographic images of molten pool during welding process under different laser powers. (a) 3.4 kW; (b) 3.5 kW; (c) 3.6 kW; (d) 3.7 kW
    Average amplitudes and standard variances of molten pool surface vibrations under different laser powers
    Fig. 5. Average amplitudes and standard variances of molten pool surface vibrations under different laser powers
    Cross section morphologies and sizes of welded joints under different laser powers. (a)(d) 3.4 kW, morphology; (b)(e) 3.5 kW, morphology; (c)(f) 3.6 kW, morphology; (g) size
    Fig. 6. Cross section morphologies and sizes of welded joints under different laser powers. (a)(d) 3.4 kW, morphology; (b)(e) 3.5 kW, morphology; (c)(f) 3.6 kW, morphology; (g) size
    Morphologies of rear welds under different laser powers. (a)(e) 3.4 kW; (b)(f) 3.5 kW; (c)(g) 3.6 kW; (d)(h) 3.7 kW
    Fig. 7. Morphologies of rear welds under different laser powers. (a)(e) 3.4 kW; (b)(f) 3.5 kW; (c)(g) 3.6 kW; (d)(h) 3.7 kW
    Microstructure of weld. (a) SEM image of weld microstructure; (b) partial magnification view of Fig. 8(a)
    Fig. 8. Microstructure of weld. (a) SEM image of weld microstructure; (b) partial magnification view of Fig. 8(a)
    EBSD analysis results of weld microstructures under different laser powers. (a)(e)(i) 3.4 kW; (b)(f)(j) 3.5 kW; (c)(g)(k) 3.6 kW; (d)(h)(l) 3.7 kW
    Fig. 9. EBSD analysis results of weld microstructures under different laser powers. (a)(e)(i) 3.4 kW; (b)(f)(j) 3.5 kW; (c)(g)(k) 3.6 kW; (d)(h)(l) 3.7 kW
    XRD analysis results of weld microstructures under different laser powers. (a) XRD patterns; (b) partial magnification view of Fig. 10(a); (c) SEM image of metallic oxide
    Fig. 10. XRD analysis results of weld microstructures under different laser powers. (a) XRD patterns; (b) partial magnification view of Fig. 10(a); (c) SEM image of metallic oxide
    Tensile properties of welded joints under different laser powers. (a) Without heat treatment; (b) with post-weld heat treatment
    Fig. 11. Tensile properties of welded joints under different laser powers. (a) Without heat treatment; (b) with post-weld heat treatment
    Fracture locations and fracture morphologies of tensile samples. (a)(b) Without heat treatment; (c)(d) after post-weld heat treatment
    Fig. 12. Fracture locations and fracture morphologies of tensile samples. (a)(b) Without heat treatment; (c)(d) after post-weld heat treatment
    Longitudinal microhardness distributions of welded joints under different laser powers. (a) 3.4 kW; (b) 3.5 kW; (c) 3.6 kW; (d) 3.7 kW
    Fig. 13. Longitudinal microhardness distributions of welded joints under different laser powers. (a) 3.4 kW; (b) 3.5 kW; (c) 3.6 kW; (d) 3.7 kW
    Chemical compositionCCrSiNiMoVMnFeCE
    Mass fraction /%0.2952.9821.0811.0510.9400.1030.702Bal.1.32
    Table 1. Chemical compositions of 30Cr3 ultra-high strength steel
    Laser powerAbsorbed energy /JStandard deviation /J

    Estimated value for standard impact

    samples /J

    Base material18.70-74.80
    3.4 kW10.411.7441.64
    3.5 kW9.232.1336.92
    3.6 kW14.360.8657.44
    3.7 kW13.920.9355.68
    Table 2. Impact test results under different laser powers
    Zhao Liu, Lihua Pan, Xiaoqiang Li, Jian Gao, Ke Zhang. Study on Microstructure and Properties of Laser-Welded 30Cr3 Ultra-High-Strength Steel Joints Based on Weld Penetration Mode[J]. Chinese Journal of Lasers, 2023, 50(12): 1202104
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