Research On The Test And Structure Of Welding Fume In Co₂ Gas Shielded Fcaw

CO2 gas sh ielded FCAW i s w idely us ed in many i ndustries, because i t ha s automated welding, high deposition efficiency and welding bead quality. However, the main disadvantage of this welding method is that when it is welding, it generates numerous fume, so that it w ill hurt the health of welders. So it is very necessary to research the testing system of welding fume in CO2 gas shielded FCAW and the basic structure of welding fume.This paper firstly introduces (GB1225-76)and the collection device of welding fume designed by another researchers and analyzes advantage and disadvantage of the two devices, then designs a new collection device of welding fume. Next it introduces how to collect and weigh welding fume. Lastly, it measures the fume forming rate of three d ifferent ki nds o f f lux-cored w ire a nd analyzes the i nfluence of w elding parameters on the fume forming rate. When arc voltage is 30V and welding current is 240A,the fume forming rate is lowest. This is because metal transfer is fine transfer, particle diameter is smaller and the transfer frequency is also higher in the condition, moreover, welding process is fine, slag covering is uniform and the weld has metal luster and beautiful shape. So, welding current between 240A and 260A is the best welding current of CO2 gas shielded FCAW in the actual production.This paper also us es high opt ical m icroscope and t ransmission electron microscopy to obs erve w elding f ume a nd di stinguish w elding f ume and w elding spatter, so that the fume f orming r ate of CO2 gas shiel ded FCAW can be more accurately determined, at the same time the reason of the new method of testing the fume forming rate is demonstrated. Welding fume formation involves liquefaction, oxidation and the final s olidification pr ocess, a nd w elding s patter only ha s t he solidification process. It also recognizes the fundamental group element of welding fume is the once particle and the basic structure of welding fume is regular chain structure and trys to find out why welding fume has this regular chain structure. At last,it uses BI-FOQELS to analyze and discuss the welding fume particle size and its distribution.