The Visual Process Control System Design Of Double-sided Gap Submerged Arc Welding For Thick-walled Member

Submerged arc welding has obvious technical advantages in the welding of medium and thick plates and long welds,and is widely used in the welding of important metal structures.Double-sided gap submerged arc welding is usually used for butt joint welding of high quality low carbon steel,low alloy steel,stainless steel thick-walled plates or cylinders.The digitalization of submerged arc welding power source control,the automation of welding production process,and the intelligent development of welding quality control have promoted the welding process to green,high quality and high efficiency.The development of a corresponding visual process control system can not only facilitate the monitoring and prediction of welding quality,achieve the purpose of quantitative evaluation and optimizing the energy consumption per unit length of weld,but also facilitate the organization of standardized production.Relying on the Key Laboratory of Construction Steel Structure and Construction Machinery of CNNC,China Nuclear Industry 23 Construction CO.,LTD.and University of South China proposed and carried out the research on online monitoring and evaluation system for welding quality of thick-walled member.The task of this project is to establish a visual process control system with welding quality prediction and evaluation for double-sided gap submerged arc welding in thick-walled member.In view of the complexity,multi-factor and experience of the welding process planning process,as well as the development status of double-sided gap submerged arc welding process and equipment,this article further investigates the interrelationship,interdependence,mutual restriction and interaction between the process parameters of double-side gap submerged arc welding and the influence on the weld appearance quality,it is believed that the extension length of welding wire should be added in the welding specification database.In order to establish the optimal design model for Double-sided gap submerged arc welding in thick-wall member,the welding speed in thick-walled member of each thickness section was changed from the constant to the variable,and the threshold range of welding current was widened.Modify the classic welding wire melting speed in terms of arc heat and joule heating wire melting nature.The concept of specific line energy and inequality constraints are introduced to ensure proper weld depth and good weld formation.The defect of incomplete penetration due to thick welding parts is solved by modifying the formula of penetration rate.The empirical formula of weld pass area is modified to make it conform to the practical principle.By clarifying the relationship between all design variables and constraints,all design variables and the objective function,and nesting treatment layer-by-layer,the welding seam dilution rate as the objective function is truly a function of all design variables,which enhances the sensitivity of the objective function to the design variables.For the integer programming of arc voltage as discrete variable,the Pappas method for stepped voltage regulation power supply and the continuous variable optimization method for stepless voltage regulation power supply are proposed.The visual process control system for double-sided gap submerged arc welding and its derived ship-shaped welding,horizon fillet welding,and one side welding both sides formation process control visualization system which developed based on Matlab GUI improve the interaction and convenience of optimized model application.After operation,the system can output the optimization results of objective function,design variables,related evaluation parameters and algorithm calculation information,which reduces the difficulty of welding quality prediction and improves the evaluation efficiency.The results have been applied in a construction company of China Nuclear Industry and Sinosteel Hengyang Machinery Co.,Ltd.,achieving the purpose of deep integration of quality technology and engineering.In view of the relationship between the welding wire melting speed and the extension length of welding wire is nonlinear in the classics,but is linear in the reconstructed DC reverse connection optimization ·model.Based on Table Curve 3D High-precision surface fitting is performed on related experimental data,and the graphical analysis results verify that the influence of extension length of welding wire on the welding wire melting speed is not a linear relationship based solely on Joule heat.The more reliable mathematical model established by mathematical processing provides a basis for refining and improving the constraint conditions of the welding wire melting speed in the DC reverse connection optimization design model in the future.