The flexural motion of a bar changes during the welding process because of the temperature field, which modifies the modulus of elasticity. Depending on the duration of heating during the welding process, the wave characteristics of the flexural motion changes; therefore, the wave characteristics can be related with the heating durations. In the present study, welding of one end of a bar to a rigid body is simulated and flexural motion generated at the free end of the bar through impulse force is analyzed. Temperature field and flexural wave characteristics are computed for different heating durations. It is found that temperature decays sharply in the region next to the heat source, and this decay becomes gradual as the heating progresses. The effect of temperature decay on the characteristics of the flexural wave is significant in the early heating period and gradual decay of temperature in the bar modifies the wave characteristics considerably.