Research on Tribological Properties of H13 Steel of Shield Machine Hob by Laser Shot Peening

In this paper, the laser shot peening technology of H13 steel is studied to improve the friction and wear performance of shield machine hob. And to utilize the laser shot peening (LSP) experiment and simulation analysis, the influence of LSP parameters on the friction and wear performance of H13 steel after strengthening is studied. The results show that the residual stress and the depth of stress layer are increased after LSP, which is beneficial to reduce the friction and wear of material surface. In addition, the surface has a paint absorption layer which can absorb laser energy to avoid surface annealing. The maximum residual stress of H13 steel is 911 MPa and the hardness is 650.7 HV, when there are three-times of black paint absorption and LSP. Compared with the raw material, the residual stress is increased by 125% and the hardness is increased by 18%. And its friction coefficients and wear volume were relatively lower than other schemes. The average friction coefficient and wear volume were reduced by 10.8% and 57.2% respectively.