Validation of evaporation-determined model of arc-cathode coupling in the peak current phase in pulsed GMA welding

Abstract

Abstract A first experimental validation of the evaporation-determined arc-cathode coupling (EDACC) model is performed by comparing the experimental and simulated current in the peak current phase of a pulsed gas metal arc welding process. For this, the EDACC model was extended to limit the cathode surface temperature to a realistic value of <2400 K. The information on the plasma for the EDACC model was gathered from literature and extrapolated and extended according to qualitative reasoning. The information on the cathode surface of the EDACC model was derived from a steady-state simulation of the weld pool, using an averaging approach over time for the energy and current. The weld pool surface temperature was compared to pyrometric measurements, that were performed for this work, and the agreement was found to be fair. The observed agreement between the modeled and experimentally determined current was within 10%. As strong assumptions were made for the comparison, the validation cannot be considered as final, but the assumptions are thoroughly analyzed and discussed. However the critical link between surface temperature, plasma temperature and total current transmitted could be reconstructed.