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CN-121988933-A - Pipeline nondestructive weld joint performance prediction method based on numerical simulation

CN121988933ACN 121988933 ACN121988933 ACN 121988933ACN-121988933-A

Abstract

The invention discloses a pipeline nondestructive weld neck performance prediction method based on numerical simulation, which comprises the steps of performing numerical simulation on a weld neck in a welding process, simulating thermal phenomena and physical phenomena occurring in the welding process by using a heat conduction model, obtaining a transient temperature field in the whole welding process, simulating and calculating weld neck residual stress based on the influence of the transient temperature field in a structure on the basis of stress and deformation fields, wherein the transient temperature field is not influenced by stress and deformation, predicting the evolution of a weld neck microstructure by using the transient temperature field, and calculating the hardness of each phase according to the predicted weld neck metallographic structure. The invention uses the heat conduction model to simulate the thermal phenomenon and the physical phenomenon in the welding process, and assists the actual welding process and the thermal simulation process to verify the structure performance of the welded junction structure in the same thermal process, thereby correcting the structure change condition of the welded junction structure in the numerical simulation process under the action of heat, accurately predicting the mechanical property of the welded junction and improving the construction efficiency of oil and gas pipeline engineering construction.

Inventors

  • QI LIHUA
  • WANG LEI
  • Gao Xiongxiong
  • YANG YAOBIN
  • CHEN YUEFENG

Assignees

  • 中国石油天然气集团有限公司
  • 中国石油集团工程材料研究院有限公司

Dates

Publication Date
20260508
Application Date
20241104

Claims (9)

  1. 1. The method for predicting the nondestructive weld joint performance of the pipeline based on numerical simulation is characterized by comprising the following steps of: Step 1, carrying out numerical simulation on a welding process of a welding port, and simulating thermal phenomena and physical phenomena occurring in the welding process by using a heat conduction model to obtain a transient temperature field of the whole welding process; Step 2, based on the influence of a transient temperature field in the structure on the stress and deformation field, simulating and calculating the residual stress of the welded junction, wherein the transient temperature field is not influenced by the stress and deformation; and 3, predicting the evolution of the microstructure of the weld neck by using the transient temperature field simulated by the heat conduction simulation, and calculating the hardness of each phase according to the predicted metallographic structure of the weld neck.
  2. 2. The method for predicting the non-destructive welded joint performance of a pipeline according to claim 1, wherein in the step 1, numerical simulation of the welding process is performed on the welded joint, modeling operation and post-processing are performed by using Abaqus finite element software, modeling is performed by using Abaqus/CAE, transportation is performed by using a static hermit algorithm Abaqus/Standard, post-processing is performed by using Abaqus/Viewer, and the pipeline model adopts a 3D model with a weld bead center as a symmetry center.
  3. 3. The method for predicting the non-destructive welded junction performance of a pipeline based on numerical simulation according to claim 2, wherein in the step 1, the heat conduction model adopts 3D linear hexahedral heat conduction unit modeling, the mesh size is set to 15 mm-25 mm in a long-distance area which is 2cm away from the girth joint to the weld line, the mesh size in the circumferential direction can be set to 4mm-6mm in a short-distance area which is 2cm away from the girth joint to the weld line, the mesh number in the depth direction of each weld bead is 3-7, and the mesh number in the width direction is 4-7.
  4. 4. The method for predicting the nondestructive testing of pipe crater performance based on numerical simulation of claim 3, wherein the heat input parameters of the heat conduction model are the process parameters in the welding process procedure used in the welding field, including welding voltage, current, welding speed and wire feeding speed, the moving heat source is a double-ellipsoid heat source model, the temperature field of the whole welding process is calculated through the heat conduction model, and when the welding heat source passes through each point position of the full-position welding, the heat source of the material in the corresponding area is activated.
  5. 5. The numerical simulation-based pipe non-destructive weld performance prediction method according to claim 1 or 4, wherein the entire welding process comprises the welding process of a root pass, a hot pass, a fill pass, and a cap pass.
  6. 6. The method for predicting the nondestructive testing of the performance of a welded junction of a pipeline based on numerical simulation according to claim 1, wherein in the step 2, in the process of simulating and calculating the residual stress of the welded junction, a linear follow-up strengthening criterion and a linear isotropy strengthening criterion are adopted, the transient temperature field point-to-point in the welding process is mapped onto a residual stress model, and the expansion and the contraction of each point on the model are calculated through the thermal expansion coefficient.
  7. 7. The method for predicting the non-destructive welded junction performance of a pipeline according to claim 1, wherein in the step 3, the evolution of the microstructure of the welded junction is predicted by using a transient temperature field simulated by thermal conduction simulation, the transient temperature field is mapped point-to-point onto the microstructure model, the microstructure components on each incremental step are calculated by USDFLD program in Abaqus finite element software, USDFLD program can extract the temperature, temperature gradient and cooling rate of each incremental step and integral point, and the toughness and metallographic content ratio are calculated and stored by internal variables.
  8. 8. The method for predicting the nondestructive testing of the performance of a pipe weld of claim 7, wherein in the step 3, the microstructure evolution of the weld is performed by a phase change map algorithm at a constant temperature, the diffusion evolution is calculated by JMAK equation, the phase change displacement is calculated by Koistinen-Marburger equation, and the model parameters are adjusted by comparing the phase change map under continuous temperature cooling.
  9. 9. The method for predicting nondestructive testing of pipe weld end performance based on numerical modeling of claim 8 wherein in step 3, the hardness of each phase is calculated based on the predicted weld end metallographic structure according to the following formula: (1) In the formula, hv represents the phase hardness, Is the hardness of ferrite and pearlite, hv B is the hardness of bainite, hv M is the hardness of martensite, 、 、 And The volume ratio of ferrite, pearlite, bainite and martensite respectively.

Description

Pipeline nondestructive weld joint performance prediction method based on numerical simulation Technical Field The invention belongs to the technical field of pipeline crater performance prediction, and relates to a pipeline nondestructive crater performance prediction method based on numerical simulation. Background The welded junction of oil gas pipeline engineering construction still only depends on nondestructive test qualification to be used as the judgment of the welded junction qualification so far. The simulation of a welding thermal process of welding heat input and the stress change condition of a welded junction after being heated by means of a SYSWELD software simulation technology are proposed by students, and the simulation is used as a thermal simulation model for calculating the stress concentration of the welded junction, but the prediction of the mechanical property of the welded junction has not been reported yet. The prior numerical simulation technology only carries out the simulation of the change of the weld junction stress and the change of the temperature field, does not effectively predict the weld junction welding process and the performance of the weld junction, does not realize the organic fusion of the interaction mechanism of the weld junction structure change and the corresponding performance in the welding special complex multilayer multipass welding thermal action process, and can not effectively predict the structure performance change of the weld junction process so far, and can not scientifically explain and quantitatively predict the influence of the change of the welding process parameters, the construction environment and the like in the construction and construction period, thereby greatly influencing the construction efficiency of oil and gas pipeline engineering construction. Disclosure of Invention The invention aims to provide a numerical simulation-based pipeline nondestructive weld joint performance prediction method, which solves the problems that the existing numerical simulation technology cannot effectively predict the weld joint welding process and weld joint performance and influence pipeline construction. The technical scheme adopted by the invention is that the method for predicting the nondestructive weld joint performance of the pipeline based on numerical simulation comprises the following steps: Step 1, carrying out numerical simulation on a welding process of a welding port, and simulating thermal phenomena and physical phenomena occurring in the welding process by using a heat conduction model to obtain a transient temperature field of the whole welding process; Step 2, based on the influence of a transient temperature field in the structure on the stress and deformation field, simulating and calculating the residual stress of the welded junction, wherein the transient temperature field is not influenced by the stress and deformation; and 3, predicting the evolution of the microstructure of the weld neck by using the transient temperature field simulated by the heat conduction simulation, and calculating the hardness of each phase according to the predicted metallographic structure of the weld neck. In step 1, numerical simulation of the welding process is carried out on the welding port, abaqus finite element software is used for modeling operation and post-processing, abaqus/CAE is used for modeling, abaqus/Standard is used for transportation by using a static hermit algorithm, abaqus/Viewer is used for post-processing, and a 3D model taking the center of a welding bead as a symmetrical center is adopted for a pipeline model. In the step 1, a 3D linear hexahedral heat conduction unit modeling is adopted for the heat conduction model, the grid size of a long-distance area which is 2cm away from the girth joint to the welding line is set to 15 mm-25 mm, the grid size of the girth is set to 4mm-6mm in a short-distance area which is 2cm away from the girth joint to the welding line, the grid number of the depth direction of each welding bead is 3-7, and the grid number of the width direction is 4-7. The heat input parameters of the heat conduction model adopt technological parameters in a welding technological procedure used in a welding field, including welding voltage, current, welding speed and wire feeding speed, the mobile heat source adopts a double-ellipsoid heat source model, the temperature field of the whole welding process is calculated through the heat conduction model, and when the welding heat source passes through each point position of full-position welding, the heat source of the material in the corresponding area is activated. The entire welding process includes the welding process of the root pass, the hot pass, the fill pass, and the cap pass. In the step 2, in the process of simulating and calculating the weld junction residual stress, a linear follow-up strengthening criterion and a linear isotropy strengthening criterion are a