Abstract: A finite element model for the wire arc additive manufacturing of single pass multi-layer H13 steel was established by using SYSWELD software. The model was validated by experiments, and the temperature field, stress field and distortion during the single pass multi-layer forming process under different inter layer cooling time (60, 90, 150, 300 s) were simulated and analyzed. The results show that the thermal cycle curve and stress distribution curve obtained by simulation are consistent with the measured results, which verifies the reliability of the finite element model. With the extension of inter layer cooling time, the heat dissipation condition of the formed part becomes stronger, the heat accumulation in the clad layer decreases, the number of weld bead remelting decreases, the maximum equivalent stress decreases from 434 MPa to 403 MPa, and the distortion decreases from 4.69 mm to 3.15 mm. When the inter layer cooling time is 300 s, the average hardness of clad zone of the wire arc additive manufactured part is 512 HV0.2, which is 2.38 times the average hardness of the annealed substrate (215 HV0.2), and the wear resistance is nearly 6 times higher than that of the annealed substrate.

Key words: wire arc additive manufacturing, thermodynamic field, numerical simulation, equivalent stress, distortion