Fig. 1. Flat samples

Fig. 2. Laser shock area and light spots overlap

Fig. 3. Schematic diagram of residual stress measurement points

Fig. 4. Schematic diagram of sample preparation corresponding and observation area to various test methods

Fig. 5. XRD pattern of repaired layer of sample No.1

Fig. 6. SEM morphology and energy spectrum scanning of sample No.1

Fig. 7. Typical surface TEM image of sample No.1

Fig. 8. Typical SEM morphology of sample No.2 repaired layer

Fig. 9. Typical TEM image of the surface area by laser shock on sample No.2

Fig. 10. Lath martensite image of the surface area by laser shock on sample No.2

Fig. 11. Residual stress measurement results of sample No.1 and No.2

Fig. 12. Schematic diagram of laser shock induced residual compressive stress