Temperature measurement inside and near the weld pool during laser welding

The work in this article deals with the measurement of temperature fields inside and near the weld pool during laser welding. The laser source used for this study is a 7.5 kW CO2 laser, and the welded material is a UNS N08904 austenitic stainless steel. The principle behind the actual experimentation is relatively simple: the welding operation is recorded with a charge coupled device camera equipped with infrared filters; after calibrating the camera sensor and image processing, the temperature distribution in the weld pool and near the melted zone is revealed.