2.6 Simulation of Weld Pool and Keyhole in Deep Penetration …
53
Fig. 2.24 Weld width varied with laser power
Figure 2.24 shows the variation of weld pool width during the increase of laser
power. With the increase of laser power, the width of the weld increases, but the
width of the middle part of the weld changes more obviously.
2.7 Numerical Simulation of Fluid Flow in Weld Pool
During Deep Penetration Laser Welding
2.7.1 Characteristics of Fluid Flow in Weld Pool
Figure 2.25 shows the velocity vector diagram of the upper surface of the weld pool
(z = 0.0025 m) when the laser power is 3000 W and the welding speed is 0.05 m/s.
It can be seen that the velocity distribution on the upper surface of weld pool is
not uniform. The velocity vectors with a velocity value of about 1.05 m/s form a
distinct circle. These velocity vectors originate from the center of the heating source
and diverge from one heating center to all sides. That is to say, the melted liquid
metal flows from the heating center to the surrounding area, and the flow velocity is
approximately the same. This convection has a higher velocity value, which indicates
that the convection heat transfer is stronger.
53
Fig. 2.24 Weld width varied with laser power
Figure 2.24 shows the variation of weld pool width during the increase of laser
power. With the increase of laser power, the width of the weld increases, but the
width of the middle part of the weld changes more obviously.
2.7 Numerical Simulation of Fluid Flow in Weld Pool
During Deep Penetration Laser Welding
2.7.1 Characteristics of Fluid Flow in Weld Pool
Figure 2.25 shows the velocity vector diagram of the upper surface of the weld pool
(z = 0.0025 m) when the laser power is 3000 W and the welding speed is 0.05 m/s.
It can be seen that the velocity distribution on the upper surface of weld pool is
not uniform. The velocity vectors with a velocity value of about 1.05 m/s form a
distinct circle. These velocity vectors originate from the center of the heating source
and diverge from one heating center to all sides. That is to say, the melted liquid
metal flows from the heating center to the surrounding area, and the flow velocity is
approximately the same. This convection has a higher velocity value, which indicates
that the convection heat transfer is stronger.