Numerical Simulation of the Effects of Scanning Velocity on the Process of Laser Transformation Hardening on the Inner Wall of Pump Barrel
This study establishes a 3-D finite element model for the numerical simulation of laser transformation hardening on inner wall of pump barrel through a finite element code-SYSWELD. The change of thermal mechanical parameters with temperature is considered. The temperature field, metallurgy transformation and distribution of residual stress are predicted. The effect of scanning velocity on the temperature, martensite fraction and distribution of residual stress are studied. The results show that peak temperature in the hardened zone reaches to 1067.0°C and the maximum heating and cooling rate of hardened zone are 1.24×104°C/s and 3.68×103°C/s. After treatment, martensite can be obtained as a main phase in the hardened zone whose fraction increases with the decrease of scanning velocity. Compressive stress could be acquired in the hardened zone while the peak of tensile stress exists in the HAZ.