| This paper proposes a synchronous heating straightening process for the deformation of the upper arch of T-beam after submerged arc welding.Three kinds of synchronous heating straightening processes are designed to straighten the 6m long Tbeam.The straightening effect of different methods is studied to verify the feasibility of the process and analyze the influence of different straightening process parameters on the straightening effect.Firstly,the temperature field of submerged arc welding of T-beam is analyzed numerically by Workbench software.Half of the T-beam was used for welding analysis,and double ellipsoid heat source was used as welding heat source for submerged arc welding to establish the thermal-mechanical coupling model of submerged arc welding.The results of temperature field analysis show that the width and depth of the T-beam molten pool are 11 mm and 7mm respectively.The temperature in the center of the molten pool is the highest and the highest temperature is about 3000℃.The temperature gradient is the largest in the fusion zone,followed by the heat affected zone and the smallest in the base metal zone.The temperature of T-beam welding process was measured by thermocouple,and the measured results were in good agreement with the simulated welding results.Secondly,the simulation results of the temperature field were loaded into the stress field as the thermal load to obtain the stress field changes of the T-beam at different times and the distribution of residual stress after welding,and the deformation of the Tbeam was predicted.After welding,the temperature on the T-beam is cooled to room temperature,the equivalent stress at the welded joints is tensile stress.The maximum equivalent stress in the fusion zone is 346 MPa,heat affected zone is next,which is283 MPa.The upper arch deformation of 6 m T-beam is 16.9 mm.The welding simulation analysis of other length T-beam shows that the longer the length of T-beam is,the greater the upper arch deformation is.Finally,the three straightening processes are simulated to obtain the distribution of the straightening temperature field and stress field as well as the straightening effect.The results show that the maximum straightening directness of process A,process B and process C is 47%,67% and 91%.The effect of process C is the best,and the final straightening result reaches the expectation.By comparing process A and process B,it can be concluded that the higher the heating temperature,the greater the degree of reverse deformation;By comparing process A and process C,it can be seen that the greater the area heated,the greater the reverse deformation,and The greater the degree of reverse deformation,the easier to achieve the purpose of straightening. |
