Experimental Analysis and Simulation of the Effect of Laser Pre-heating on the Temperature and Thermal Stress Fields of a H13 Steel Substrate Laser Clad with Ni60
H-G. Yin, J-H. LI, F-P. Yao, L-W. Zhao and Y. Wu
The temperature field and thermal stress field of the fibre laser pre-heating process of H13 steel substrate are simulated by COMSOL software and the optimal pre-heating power is obtained through experimental verification. For the temperature field the temperature change of the H13 steel substrate surface gradually becomes stable after the laser beam pre-heats for three times and the temperature of the substrate reaches the pre-heating temperature under the pre-heating power. The pre-heating temperature of the H13 steel substrate increases with the increase of the pre-heating power. For the thermal stress field the maximum thermal stress is mainly concentrated on the bottom of the H13 steel substrate and it increases with the increase of pre-heating power. The thermal stress on the surface of the H13 steel substrate is less affected by the pre-heating power. The maximum thermal stress distribution in the middle of the H13 steel substrate decreases with the increase of pre-heating times. Experimental verification results show that the red-brown oxide film formed on the surface of the H13 steel substrate will damage the metallurgical bond between the Ni60 laser clad coating and the H13 steel substrate. When the pre-heating power reached 300 W there is no red-brown oxide film and other impurities on the surface of the H13 steel substrate and the metallurgical bond between the Ni60 laser clad coating and the H13 steel substrate is good.
Keywords: H13 steel, Ni60 alloy, laser pre-heating, laser cladding, temperature field, thermal stress field, simulation, finite element (FE), COMSOL