Welding Forming Control Method Of T/K/Y Joint Of Catheterostat

Welding is the key manufacturing process of offshore wind power heavy equipment,which is widely used in the manufacturing of wind power pipe rack.At present,most of the welding of catheterostat still uses manual welding,which has a serious impact on actual production efficiency and welding quality.Therefore,it is of great significance to improve the production efficiency and welding quality and reduce the production cost in the field of wind power welding.Aiming at the urgent need of multi-layer and multi-channel automatic welding of T/K/Y intersection of catheterostat in offshore wind power industry,this paper constructs a model of the relationship between multi-layer and multi-channel welding process parameters and weld bead shape.It reveals the inherent law,guides the implementation of welding process,and realizes the forming control and prediction of base welding and filling welding of catheterostat intersecting groove.It is of great significance to improve the multi-layer and multi pass automatic welding of large steel structure with complex groove.In order to realize the forming control and prediction of multi-layer and multi pass welding of catheterostat intersecting groove,this paper studies the bead shape control of backing welding,single pass filling welding and multi-layer and multi pass filling welding,and establishes the prediction model.Firstly,the multi parameter coupling effects of welding voltage,welding current,welding speed,weld cross-sectional area,weld height and weld fusion ratio of the base welding layer of catheterostat intersecting groove were studied by response surface central composite design method.It effectively reveals the functional relationship between the welding process parameters and the geometric characteristics of the backing welding,and realizes the control and prediction of the automatic backing welding of the catheterostat intersecting groove,and the accuracy of the model is within 6%.Secondly,the control method of forming the first pass of each layer into a parallelogram weld section is proposed.The input variables are welding voltage,welding current,welding speed and welding torch swing.Taking the aspect ratio,area and angle of the welding seam as the output indexes,the functional relationship between the input variables and the output indexes is constructed.The control and prediction of the weld contour of the parallelogram section shape of the filling welding are realized,and the accuracy of the model is less than 5%.Then,the quality control of single layer and multi pass forming of filler welding is studied.The influence of initial position of welding torch,swing of welding torch and welding speed on the residual stress,flatness and deformation of single-layer multi pass filling welding was studied by orthogonal experimental design.On the basis of signal-to-noise ratio conversion,the goal of low residual stress,high flatness and small deformation is achieved by applying grey correlation analysis.Finally,the multi-layer and multi pass welding tests of the catheterostat intersecting groove are carried out,and the joint reliability is tested by impact test,tensile test and electrochemical corrosion test.The average tensile strength of the sample is 572 Mpa,the impact energy at the fusion line is 51 J,and the minimum impact energy at the weld is 105 J and the corrosion rate of the weld is lower than that of the base metal,and the test results all meet expectations.The research results can provide theoretical basis for multi-layer and multi-channel welding forming mechanism,control method and multi-layer and multi-channel welding technology of catheterostat intersecting groove.It can also provide technical methods and theoretical basis for the future development of all position automatic welding of catheterostat intersecting groove,all position automatic welding robot and Application Research of multi-layer and multi pass welding process of complex structural parts.