Prediction And Control Of Welding Deformation Of Long Rod

Taking mast welding structure of the rotary drilling rig as example, analyze productionmechanism and its change rules for welding deformation of long rod in combination withcurrent product distribution of company. Study welding deformation of the mast of the rotarydrilling rig and propose corresponding process measures for controlling welding deformationthrough model test of orthogonal design and monitoring conditions at site.Apply orthogonal test method to carry out model test, investigate influence of reversedeformation quantity, welding sequence and corresponding welding parameters (current,voltage) on welding deformation. Result shows that reverse deformation quantity and weldingsequence have great influence on welding deformation. In order to reduce weldingdeformation, optimized process is:⑴determine reverse deformation quantity, pre-set reversedeformation;⑵change of welding sequence, apply rib continuous welding and symmetricskip welding of main welding seam from middle；⑶welding parameter applies valuespecified in welding process evaluation.The structure is properly divided into sections, nine points and eleven point markingmethods are applied during monitoring at site, set pre-set reverse deformation and way toimpose force in combination with deformation, it is welded in three steps, each step ofwelding follows sequence proposed in model test, main welding seam applies determinedstandard symmetrical skip welding so as to reduce influence of linear energy on structure andreduce welding stress during welding process. Finally it is realized to effectively controlwelding deformation and produce work pieces in accordance with technical requirements.Take advantage of one approximate engineering calculation method, estimate weldingdeformation and compare with actual measurement results, correct this approximatecalculation way after analysis and study, make obtained result coincide with the approximateengineering calculation result, it means it is feasible to estimate welding deformation of themast by approximate calculation method. Process method for controlling deformation of themast is applied in production according to the entire test result, obtaining good effect.Research result makes foundation for further deformation analysis about welding of the longrod.