Numerical model of transient convection pattern and forming mechanism of molten pool in laser cladding

Because the convection pattern inside the laser cladding transient molten pool is difficult to measure by experimental means, the numerical analysis model of the inside of the laser cladding molten pool was constructed, and the forming mechanism of the cladding layer was simultaneously analyzed. The internal convection pattern of the single-track, multi-track and multi-layer laser cladding molten pool was analyzed. The results show that the convection inside the laser cladding molten pool in different types is mainly annular convection. The fluid at the bottom of the molten pool flows to the surface of the molten pool, and the fluid on the surface of the molten pool flows along the sides to the bottom of the molten pool. Therefore, the cladding layer is mainly solidified by the fluid flowing from the bottom of the molten pool to the surface of the molten pool.