Prevention and mechanical analysis of porosity formation in pulsed CO2 laser welding of 30CrMnSiA

Porosity formation in high power laser welding,which is related to the characteristics of high power laser welding,is an important problem of welding quality.The pulsed CO2 laser welding was employed to prevent porosity in partial penetration.The experimental results reveal that the porosity ratio decrease with increasing pulse frequency when the pulse frequency is below 50Hz,and is nearly kept constant in the range of 50Hz~200Hz.Moderate increase of the duty ratio is benefit to the reduction of porosity.