The Experimental Study On Optimization Of Gas Shielded Welding Parameters For Automatic Forming Of Concrete Reinforcement Skeleton

On the basis of advocating"green"architecture in the 13th five-year Plan,as the"skeleton"of assembled architecture,the quality of shaped steel bar skeleton is the most important and plays an important role in modern architecture.Welding,as a kind of connection with good quality and simple operation,is widely used in steel bar joint structure.Carbon dioxide gas shielded welding?CO2 welding?has been applied to weld steel bar skeleton in automatic forming production line because of its high efficiency,and is economic and easy to realize automation.In the welding process,the welding process parameters and the microstructure of the heat have great impact on the welded joint have the properties of the whole steel bar skeleton.Therefore,Therefore,higher requirements are put forward for the adjustment of welding process parameters.According to the welding principle of CO₂ gas shielded welding and the requirements of welding environment.Based on the study of the causes and types of welding defects of welded joints,the production plan of automatic welding of steel skeleton is finally formulated.The quality inspection standard of the main reinforcement and stirrup in the reinforcement skeleton is studied,which provides the theoretical basis for the later mechanical performance experiment of the reinforcement skeleton.According to the characteristics of the microstructure of the welded joint of the reinforcement framework,the theory of the microstructure of the reinforcement welding is studied.The area near the welded joint of reinforcement framework is divided into weld area,fusion area and heat affected area.To understand the micro metallographic structure in different areas and the macro mechanical properties of the regional metallographic structure,so as to provide micro theoretical support for further optimization of welding parameters.Based on the previous theoretical research,the four welding parameters of welding current?A?,arc voltage?V?,welding time?s?,hoop spacing?mm?are selected as the experimental factors according to the main welding parameters of the automatic forming production line of steel bar skeleton at the present stage and the preparatory tests in the early stage.The orthogonal table of the selected process parameters is established by SPSS software tool,and the tensile strength,yield strength and extension rate of the tensile specimens are taken as the best combination of welding parameters.Then the steel is determined by welding quality effect diagram and extreme difference analysis.The best combination of welding parameters of reinforcement and bone frame is obtained,and the primary and secondary conditions of the influence of these four welding parameters on the welding quality of steel bar skeleton are obtained at the same time.Finally,the best combination of process parameters selected in the experiment is applied to verify the production and compared with the actual production.It is proved that the optimized welding process parameters improve the excellent welding rate by about 15%,which lays the foundation for the research and development of the automatic forming production line of steel skeleton.On the premise of macroscopical optimization experiment of welding parameters of steel bar skeleton,four other groups of welding parameters,welding current?A?,arc voltage?V?,welding time?s?,welding torch angle?°?,were selected for orthogonal test to determine the best combination of parameters.By controlling the welding time to carry out single factor welding test,the microstructure of the steel skeleton specimens welded with different welding parameters was observed.According to the difference of mechanical properties of different metallographic structures,the parameters with the best properties are selected.Finally,through the verification test,it is proved that the excellent and good rate of the optimized welding process parameters is increased by 10%,which further provides technical support for the automatic production of steel bar skeleton.