Study On Arc Plasma Radiation And Its Application On Welding Process Inspection

Arc welding as a very important method of heat processing technology occupies the irreplaceable status in some manufacturing."High-quality, low-cost, automated"will become the forefront and hot of future welding technology and development. So online monitoring and control of welding quality is seems to be particularly important. A new approach was provided for the online detection and control of welding quality in this paper.On the basis of the physical principle of the arc plasma spectrum, the physical essentials of the arc plasma can be actually reflected by the arc spectrum information. It can be realized through spectrum information technology to refine the arc light and separate good quality spectrum signal, which can reflect the quality of welding. Compared with other present methods of arc sensing, the spectrum information technology has such advantages as plentiful information, high sensitivity, good selectivity, fast response speed, high special-time resolution and good performance of anti-disturbance.With the analysis of radiation theory and distribution feature of the arc plasma, standardize spectrum collected in TIG and MIG welding process, choose the Fe and Ar atoms lines as study object. Boltzmann graphic method and Abel transform were used to calculate the plasma temperature, space distribution of arc-ray which is used to characterize the characteristics of the arc plasma.We collected TIG welding arc light spectrum of steel with disturbing factor such as rusty and various gas flow rate and compared with normal welding process in the trial. And got the conclusion that different disturbing factor had different signal characteristic which could provide assorting diagnose criterion for disturbing factor. Based on the above study, we also designed a more practical sense of the arc spectrum acquisition and analysis system, and was used in MIG welding spectrum acquisition test under different welding parameters. The results show that the analysis and acquisition system can exactly determine the form of metal transfer, the changes in element concentrations and the change of arc length.