1：Experimental Design and Method Selection

A hybrid surface modification approach using a high-power diode laser (HPDL) and large pulsed electron beam (LPEB) irradiation was proposed. The HPDL irradiation was applied to AISI 304 SS surfaces at various scan rates to induce surface melting of substrates, thereby eliminating non-metallic inclusions. The LPEB irradiation was then applied to the HPDL-treated surfaces to further modify the surface characteristics.

2：Sample Selection and Data Sources

AISI 304 stainless steel samples (40 × 40 mm2) were used. The surface area of substrates was fully scanned using X/Y-translation stages for both HPDL and LPEB treatments.

3：List of Experimental Equipment and Materials

High-power diode laser (Directprocess 900; Directphotonics), large pulsed electron beam setup, white-interference microscopy (NV-3000; Nanosystem), two-dimensional profilometer (SV-C3100; Mitutoyo), field-emission scanning electron microscope (FE-SEM; Nova Nano 230; FEI), energy-dispersive X-ray spectrometer (EDS), X-ray diffractometer (XRD, D8 Advance; Bruker), three-electrode electrochemical system (IVIUMnStat; IVIUM Technologies).

4：Experimental Procedures and Operational Workflow

HPDL irradiation was performed at scan rates of 150, 300, and 600 mm/min under ambient conditions without a shielding gas. LPEB irradiation was performed with a cathode voltage ranging from 0 to 30 kV and solenoid voltage ranging from 0 to 1.5 kV, with a pulse duration of 2 μs and a dwell time of 10 s between each pulse. The hybrid treatment involved HPDL irradiation followed by LPEB irradiation.

5：Data Analysis Methods

Surface qualities and crater generation were evaluated using white-interference microscopy and profilometry. Microstructural characterization was performed using SEM, EDS, and XRD. Corrosion behavior was assessed using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS).