Abstract: In order to avoid the microcrack defects, the thermal-mechanical coupling problem is analyzed adopting a numerical approach during the wear shaft surface laser cladding. The mathematical model of nonlinear transient analysis is established based on the wear surface laser cladding experiment, then an ordered discrete grid algorithm is using to realize three-dimensional finite element model of the shaft surface laser cladding process. The transient thermal- mechanical cycle and its coupling problem during multi-tracks cladding metal powder ring deposition process are solved by a developed subprogram with ANSYS parametric design language (APDL) and the finite element kill and birth technique. The distribution of temperature and thermal stress are obtained in the cladding process. Simulation results indicate that temperature gradients of the molten pool are larger and the highest temperature is 2035.99℃ which located in the adjacent area of spot center location. Transient temperature variations of the nodes on different cladding tracts are similar and arrive behind the load time. The cladding residual stress associated with temperature gradient and the peak residual stress(about 279 MPa)occurs in substrate metal adjacent heat affected zone (HAZ), which are in a good agreement with experimentally obtained results. The paper has a guiding significance to process optimization of the wear shaft surface laser cladding.

Key words: experiment verification, laser cladding, numerical simulation, shaft surface, thermal-mechanical cycle