Fig. 1. Images of reinforced area. (a) Front image; (b) cross-sectional image
Fig. 2. Metallographic structures of different areas. (a) Strengthened area; (b) heat-affected zone; (c) matrix area
Fig. 3. SEM morphologies at different positions of strengthened zone. (a) Local morphology of strengthened zone; (b) position A, surface morphology of strengthened zone; (c) position B, morphology in the middle of strengthened zone; (d) position C, morphology of side edge of strengthened zone; (e) position D, morphology of bottom edge of strengthened zone
Fig. 4. Schematic of the line scanning direction of the energy spectrum in strengthened zone
Fig. 5. Spectral diagram of strengthened zone along the scanning direction
Fig. 6. Schematic of the position of microhardness testing points
Fig. 7. Microhardness curves of samples before and after laser strengthening
Fig. 8. Polarization curves of samples before and after laser strengthening
Fig. 9. Friction coefficient versus time for samples before and after laser strengthening
Fig. 10. SEM morphologies of samples before and after laser strengthening. (a) Before laser strengthening; (b) after laser strengthening
Element | C | Si | Mn | P | S | Cr | Mo | Ni | Fe |
---|
Mass fraction /% | ≤0.08 | ≤1.00 | ≤2.00 | ≤0.035 | ≤0.030 | 16.00‒18.50 | 2.00‒3.00 | 10.00‒14.00 | Bal. |
|
Table 1. Chemical composition of 0Cr17Ni12Mo2 steel
Sample | Corrosion current /µA | Equilibrium potential /mV | Area /cm2 | Corrosion current density /(µA·cm-2) | Cathodic Tafel slope | Anodic Tafel slope |
---|
Before laser strengthening | 4.819 | -906 | 1 | 4.819 | 6.327 | 4.505 | After laser strengthening | 7.889 | -359 | 1 | 7.889 | 4.190 | 5.069 |
|
Table 2. Electrochemical corrosion related data of samples before and after laser strengthening