Study on Temperature Field Detection Technology of Molten Pool Based on Color Thermometry

The temperature field distribution of molten pool affects the quality of welding process directly, study on the temperature field distribution of molten pool to improve the quality of welding process is of great significance. The temperature field distribution of molten pool under Cold Metal Transfer(CMT) welding process is studied in this paper, a temperature field detecting system for molten pool is designed based on color thermometry, the system is mainly composed of spectroscope, filter, Charge Coupled Device(CCD) camera, computer and Field Programmable Gate Array(FPGA). The FPGA triggers the CCD camera when the welding current is at the base value under the CMT welding process, in this way, the acquired molten pool images are almost unaffected by arc light. The formula for calculating the temperature field of molten pool is derived, and the experimental verification is carried out. The experimental results show that: Under the CMT welding process, the designed temperature field detecting system is almost free from the influence of arc light, and it can detect the temperature field distribution of molten pool in real time.