1：Experimental Design and Method Selection:

The study involved laser cladding of AISI 420 SS powder onto an A36 steel substrate, followed by low-temperature tempering at 210°C for 1 hour. Microstructure and properties were analyzed using XRD, SEM, TEM, micro-hardness testing, tensile testing, and electrochemical polarization tests.

2：Sample Selection and Data Sources:

An A36 steel plate was used as the substrate, and spherical gas-atomized AISI 420 SS powder was supplied by Changsha Tianjiu Materials Ltd. Specimens were extracted from the laser-cladded coating before and after tempering.

3：List of Experimental Equipment and Materials:

Equipment included a TJ-HL-T5000 5 kW CO2 laser, Miniflex600 XRD, TM3030 SEM, JEOL-2100 TEM, HMV-2T micro-hardness tester, PWS-E100 universal testing machine, and CS300 electrochemical workstation. Materials included AISI 420 SS powder and A36 steel.

4：Experimental Procedures and Operational Workflow:

Laser cladding was performed with specific parameters (laser power

5：5 kW, scanning speed 6 mm/s, etc.), followed by tempering. Specimens were machined, polished, and characterized using various techniques. Tensile and corrosion tests were conducted according to standard methods. Data Analysis Methods:

Data were analyzed using techniques such as phase identification from XRD patterns, microstructural observation with SEM and TEM, hardness measurements, tensile property evaluation, and electrochemical parameter calculation from polarization curves.