Application of Active Thermography in the Quality Control of Laser-Welded Overlap Joints

The article presents possibilities of using active thermography as a non– destructive method verifying the quality of laser-welded joints made of steel sheets. The article presents the testing methodology and the preparation of test joints as well as describes a new test rig currently implemented in the company. Thermographic images obtained in the tests were subjected to image analysis processing performed to identify the maximum “temperature” gradient distribution in the test joints. The thermographic image analysis results were verified by cross-sectional macroscopic tests performed in accordance with currently valid standards. The results obtained in the tests confirmed that the method developed and implemented in the company can be successfully applied when assessing the quality of laser-welded lap joints. The article also includes a brief description of SITECH Ltd.