NUMERICAL ANALYSIS OF TRANSIENT DEVELOPMENT OF TEMPERATURE FIELD IN KEYHOLE PLASMA ARC WELDING
小孔等离子弧焊接热场瞬时演变过程的数值分析

With considering the characteristics of keyhole plasma arc welding and the plasma's " digging " action to the weld pool, a new welding heat source model (transient thermal model for plasma arc welding, TPAW) is proposed to describe and reflect the " reversed bugle " configuration of weld cross section under plasma's action and the heat intensity distribution along the workpiece thickness direction. Based on TPAW, finite element calculation of temperature field in keyhole plasma arc welding is conducted, and the transient development of weld pool and surrounding thermal profiles are analyzed. The predicted weld geometry and the time needed to reach the quasi-steady state are in agreement with the experimental measurements.