Studies On Technological Factors Impact And Prediction Of Fume Emission Rate In Gas Metal Arc Welding

A large number of welding fumes are produced during the welding process of gas mental arc welding.The metallic oxide in the welding fume not only pollute the environment but also directly affect the health of the welding workers,which is not consistent with the concept of sustainable development.Therefore,reducing the welding fume emission rate?welding fume formation rate and welding fume generation rate?has become an important problem that must be solved in the welding industry.Choosing appropriate welding process parameters and analyzing the influence of welding process factors on the welding fume emission rate can help reduce the harm of welding fumes.To this end,the orthogonal experiment was carried out with the development of wire feed speed detection device,CO₂ gas shielded welding with solid wire had taken as the research object.The welding current,welding voltage and welding speed had taken as the three factors of the experiment.And the welding fume formation rate and fume generation rate had taken as the experimental indicators.The analysis of variance analysis and range analysis of the orthogonal experiment data show that the main influencing factors of the welding fume emission rate are welding voltage and welding current.while the welding speed has no significant influence on the welding fume emission rate.When the welding process factor parameter is that the welding current was 170 A?200 A,the welding voltage was 22 V?24 V,the welding speed was 26 cm/min,the welding fume formation rate was the lowest;when the welding process factor parameter was that the welding voltage was 22 V?24 V,welding current was 290 A?320 A,welding speed was 26 cm/min,the welding fume generation rate was the lowest.Based on the optimization analysis of experimental data,it can be seen that the welding fume formation rate and fume generation rate are increased firstly and then decreased with the increased of a certain parameter in welding current,welding voltage or wire feed speed.However,the parameters of the welding process factors corresponding to the extreme values of welding fume formation rate and welding fume generation rate are different,that is,the influence rule of the welding process parameters on the FFR and FGR is obviously different.When selecting the low-fume and environmental-friendly welding process parameters,it is necessary to pay attention to the difference between the measurement standards of the welding fume emission rate.The effect of welding current and wire feed speed on the welding fume emission rate is basically the same.The SEM investigation of welding fumes shows that during the CO₂ gas shielded welding with solid wire process,a large number of reticulated fume floc and a few micron-sized spherical fume particles were formed.The EDS results show that fume is mainly composed of oxides of Fe,Mn,and Si elements.The change of the current and wire feed speed can affect the elemental proportion of fume flocks.The flux cored arc welding fume emission rate prediction model can help to reduce welding fume from the perspective of welding process factors.the BP neural network and Elman neural network prediction models based on welding process parameters were established to realize the numerical prediction of the fume formation rate of flux cored arc welding.BP neural network prediction results was better than Elman neural network in the error percentage,R-Square and mean square error value field.