Role of surface-active elements during keyhole-mode laser welding

摘要: During high power density laser welding of mild steel, the keyhole depth, liquid metal flow, weld geometry and integrity are affected by base-metal sulfur content oxygen (O2) present in atmosphere or shielding gas. The role these surface-active elements during keyhole-mode steels is not well understood. In order to better understand their effects, steel specimens containing various concentrations examined. addition, a numerical model used evaluate influence on heat transfer fluid flow welding. Increase concentration O2 gas results decreased widths. Sulfur negligible increase penetration depth whereas presence significantly affects penetration. It has earlier been proposed that oxygen, if gas, can get introduced into pool resulting formation carbon monoxide (CO) at surface additional pressure from CO result increased Numerical modelling this work effects geometries.