Monitoring And Research Of Resistance Spot Welding Spatter

Resistance spot welding technology has become an indispensable welding technology in industrial production due to its high production efficiency and easy automation,and with the development and progress of the times,the welding quality requirements of resistance spot welding are also Higher and higher.In the process production of resistance spot welding,spatter is a very common phenomenon.The generation of spatter is often accompanied by bad solder joints,and the quality of solder joints directly determines the quality of the entire product.There are many factors that lead to the occurrence of spatter.When spatter occurs,it will consume a lot of time and labor costs by adjusting the welding process parameters and assembly parameters to eliminate spatter.This paper takes DP590 steel as the research object,mainly studies the characteristics of spatter caused by different factors,and establishes a resistance spot welding spatter monitoring system.An orthogonal test of three levels and three factors of welding current,welding time and electrode pressure was designed to determine the optimal welding process parameter group for DP590 steel.In order to better study the influence of different parameters on the spatter during the welding process,three levels of welding current(I),welding time(T)and electrode pressure(F)are selected as three levels.,and the misalignment of the electrode leads to the offset of the nugget position(E_o),the electrode rod and the workpiece are not perpendicular to the angle deviation(E_a),the electrode surface is worn(E_w),the distance between the plates at the overlap of the workpiece(W_d),and the surface of the workpiece has oil pollution(W_s)take 2 level,mixing level uniform orthogonal test was designed,combined with logistic regression equation,the calculation formula of spatter probability of DP590 steel is obtained.The welding current is greater than the threshold current,the welding time is longer than the threshold time,the electrode pressure is lower than the threshold pressure,the distance between the parts to be welded,the electrode rod is not perpendicular to the workpiece,the electrode surface is worn,and the welding spot is located at the edge of the work-piece are respectively set as single variable in the parameter setting of resistance spot welding,and the spatter images under different factors are collected through the self-built image acquisition hardware system.The collected spatter images are uniformly preprocessed,and then image processing with different algorithms is performed for the spatter images with different characteristics,and finally the spatter characteristics caused by various factors are obtained.Based on the spatter features obtained after image processing,a general database is established,and the spatter features and their corresponding spatter-generating factors are put into the general database as a sub-database.Then,a spatter monitoring system of resistance spot welding based on DP590 steel is established by programming in python.The spatter monitoring system will process the original spatter image collected by the hardware system,and a series of image processing is performed according to the internal program,and the results are compared with the data in the database,and the system will finally output the cause of the spatter.